# Stepepper motor not moving but step and dir pin getting the pwm

i am trying to run 3 stepper motor using 12v 5 amp smps, arduino and cnc shield,i programmed it i could see the pwm in step and dir pin, but just getting 12 v at the coil of motor it is not changing in accordance with pwm, i asdjusted vref too

Hello.

I moved your post to the “Motor controllers/drivers and motors” section of the forum.

Are you still using the same setup that you were having problems with before? Similar to your previous post, you still are not posting enough information for us to offer any meaningful help. If you have not done so, I suggest reading our “Support” page as I suggested before.

For example, what stepper motor and stepper motor driver are you using, and what voltage is VREF set to? Additionally, since you are having problems getting it working with your CNC shield, I recommend simplifying and testing a single stepper motor driver at a time. We have a minimal wiring diagram for each of our 16-pin stepper motor drivers posted on their respective product pages, so you can use that as a reference to make sure your connections are appropriate. If you try that and have problems, can you post details about the results as well as pictures of your setup that show all of your connections?

Brandon

how much voltage will go for each coil sir, vref=0.77

The relationship between VREF and the current limit depends on which driver you are using, which you have not specified yet. If you would like further assistance, please answer the questions from my previous post.

Brandon

i am using drv 8825,vref to 0.72

As described on the DRV8825 carrier product page, the equation for the current limit is:

Current Limit=VREF×2

So, with a VREF of 0.72V, the current limit would be set to 1.44 A per phase.

Brandon