DRV 8825- Microstepping shifts to 1/8th randomly

Hi There,

We have configured DRV8825 module to 1/16 microstepping mode using resistors on Mode 0, Mode1 & Mode 2 pins. (Mode0=Mode1=Low, Mode2=High).
We noticed (based on the motor movement and the speed) that the module randomly goes in 1/8 microstepping mode, causing a bit noisy motor rotation.
During motor revolution, we checked the voltage levels on the Mode 0/1/2 pins, we noticed that they are at correct state/level.
We have faced this problem with multiple units.
Has any one noticed this and what is the possible solution to this ?
We have following config.
STEP=DIR= 5V logic.

Please guide.

Best regards,

Hello, Rajesh.

Can you post some pictures of your setup that show the board’s connections and tell me what resistor values are connected to each of the Mode pins?

What specific behavior are you seeing that makes you suspect the driver is changing microstepping modes? Based on your description, one possibility is that the load is too high for your current combination of power supply and driver settings resulting in the motor skipping every other step. A video showing the behavior would be helpful. The forum does not allow users to post very large videos, but it does work well with videos linked from other sites (like YouTube or Vimeo).

- Patrick

Hello Patrick,
Thanks for your reply.
The motor speed increases and the motor travels half a distance when it changes (microstepping) mode. For eliminating the doubt related to the load we tried rotating the motor without load but the motor still continues to misbehave even without load.
We have used 4.7K for mode2 pin pull up. other mode pins are open as it is internally pull down.
Best regards,

The pull-up choice sounds fine.

The motor increasing speed but not traveling as far does not make sense. If the driver and motor is shifting from 1/16 microstepping to 1/8 microstepping, then its speed should double causing the motor to travel twice as far in the same amount of time/pulses.

Can you post pictures of your setup and a video like I suggested previously?

- Patrick