Activating Pololu DRV8825

I try to operate the Pololu DRV8825 board using your standard proposed schematic.
The motor is not spinning smooth and the motor stops spinning at STEP frequency above 10KHz.

to troubleshoot, I connected 30ohm resistors instead of motor, to see the current. I measure driver output voltage and phase current. At the region where the current should be zero, there are high frequency pulses on driver outputs. The frequency is much higher than STEP frequency.

In addition, configuring the MODE pins would not change the steps. The driver outputs only full step and half step.

Driver setting:
STEP= Pulse generator 0/3.3V
Motor Power = 24V

Kindly provide direction.

Additional information

The voltage on pins 1 and 2 (charge pump) is not stable

Hello, Igor.

I am sorry you are having problems with your stepper motor and driver. Could you tell me more about your setup? What stepper motor are you using? Could you provide a link to its specifications or datasheet? What are you using to supply the logic signals to the driver? How does the stepper motor behave at lower step rates? Could you post pictures of your setup that show all the connections? Could you also post close-up photos of both sides of your board so I can inspect the soldering?

- Jeremy

Attached is the schematic I use.
I have problems also when I connect pure resistor instead of motor. I am attaching sketch of scope screen
I asked professional to look see soldering, they are good.

Hope this helps


Thanks for posting those pictures; however, it is unclear from your sketch of your scope what is going on. What are you measuring with your oscilloscope? Could you try taking a photo of your oscilloscope screen so it shows relevant grid information? Could you also answer all the questions and provide the information I asked for in my previous post?

- Jeremy