L6474 -- much faster in forward direction than in reverse?

dvelasco · ‎2015-06-22

Posted on June 22, 2015 at 16:05

I've been encountering a strange problem. I can use the L6474 to move a stepper motor pretty fast in the forward direction. When I flip the direction bit though, I find that I can't make it move anywhere near as fast in the reverse direction. Any idea what might be causing this?

Enrico Poli · ‎2015-07-01

Posted on July 01, 2015 at 13:53

Hi,

How much is the speed difference? Whant is the mechanical load of the motor?

Enrico

dvelasco · ‎2015-07-15

Posted on July 15, 2015 at 21:54

Sorry for the late response, but I didn't see your reply earlier.

This happens even on an unloaded motor. I don't have a precise speed measurement available, but I believe that it happens at around 144000 pulses per second. I did some ad hoc changes to the firmware that seemed to mask out this problem, so I don't have any specifics on hand about the speed difference.

Still, the fact that this occurs on a completely loaded motor is strange.