Micro stepping issues with DRV8825

I am using a NEMA17 stepper, 1A, 1.8 degree motor and it runs normally at full(200 steps), 1/2(400 steps) and 1/4(800 steps) . When I set up the program for one revolution at 1/8 stepping (1600 steps per revolution) the motor makes two revolutions instead of one.

I may have found the issue with the driver. It appears that the M0 line is not being recognized when it is pulled high. All micro stepping functions seem to work normally except when M0 is needed. I mistakenly said that 1/2 step was working normally and in fact it is not.

Hello.

Can you post some pictures of your driver and setup that show how everything is connected? Could you also use a multimeter to verify that you are actually driving M0 high when your system is operating, as well as to check the resistance between M0 and GND with the driver unpowered and disconnected?

- Patrick


Breadboard setup I am using. The resistance between the ground pin and M0 is infinite. The M0 pin has
5 volts on it when the jumper is installed on M0 pin. The picture is somewhat deceiving because of the angle.
The ground jumper appears to be on pin 10, but it is on pin 9 (gnd) of the 8825. M1 to gnd is 94.3k. M0 is open???

On careful inspection, it looks like the driver you have is probably a knockoff and not manufactured by us. (I suspect that will be more apparent if you compare the bottom of your board to our carrier.) That makes it difficult to say for sure what might be causing the problem, and we cannot help you troubleshoot it since it is likely different than ours.

If you want to try a genuine Pololu DRV8825, then you can find them on our website, or you can get them from our authorized distributors. If you have the same problem with one of our boards, I would be happy to help you continue troubleshooting.

- Patrick

Thanks for you time and effort. Sorry, I thought I had bought these from Pololu. I’ve had them laying around
here for a couple of years. Thanks again.

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