I have a stepper driven by one of the usual, chinese stepper driver boards.
STEP+DIR signal are looking good.
Problem: the stepper is moving only in one direction.
Any idea where I could look?
I checked the cabling. enable + and- on GND. step+ and dir+ on +5V, step- and dir- pulled low by OC outputs.
I switched the 4 stepper cables around.
I played with 5us and 3us instead of 1us pulses.
Second stepper-driver shows the same behavior.
step+dir of another axis show the same behavior.
Stepper driver is an fmd2740a.
I had the same problem when I first set up my motors. I was informed that if the end stop values are not correct it will only move in one direction. I can’t remember exactly what had to be changed I think it had to changed from normally closed to normally open, but @ThantiK was the one that helped me and maybe he can shed a little more light on the solution.
There are no end stops configured and switching from the Z to the X outputs shows the same issue.
On the sanguinololu, incorrect fuse settings in firmware can cause this - http://reprap.org/wiki/Sanguinololu#Fuse_Settings
Are you sure the wiring is correct? Maybe the docs are lying to you. http://reprap.org/wiki/Stepper_wiring#Methods_and_procedures
Yes, the stepper itself is wired correctly.
Works fine when driven by the A-axis stepper driver using identical wiring.
I’m not sure the stepper driver is labeled correctly but I can confirm that the EN-pair is indeed where it is and that STEP and DIR pairs are not switched.
@Stephen_Baird this is no sanguinolu.
FOUND IT
Aparently the ENABLE is not a real differential signal.
ENABLE- and ENABLE+ must be HIGH.
If one is low and one is high, it’s properly disabled.
However if both are LOW then it happily steps…and ignored direction.