Pololu Robotics & Electronics
My account Comments or questions? About Pololu Contact Ordering information Distributors

Pololu Forum

Problem with NEMA 23 Stepper run by a DM542T driver

I am attempting to run a NEMA 23 stepper motor with a DM542T driver from a Raspberry Pi 3b+ using Python. I am supplying the driver with power from a 24VDC 10A Power Supply. The positive PUL and DIR terminals are being powered through a 5V buck converter(with a MAX output of 3A) from the same 24V 10A power supply mentioned previously. The negative PUL and DIR terminals are connected to GPIO pins on the Raspberry Pi. Whenever I pulse the PUL pin, the motor steps, but less that expected based on the micro stepping setting on the driver and the 1.8 degree step angle from the motor. Additionally, when the DIR pin on the Raspberry Pi is activated and I pulse the motor, the motor does not move and makes a high pitched squealing sound. The current setting on the driver is set correctly for the motor’s specifications, and I have made sure the voltages are correct at each terminal with a volt meter.

The driver manual indicates that the Logic Signal Current needs to be between 7 and 16 mA, and I am not sure what signal that is referencing. I feel like that parameter may be the issue, but I could be completely wrong. If you have any suggestions on how I could get the motor to run properly, they would be very much appreciated.


It does not sound like you are using any of our products, so we cannot really offer any meaningful advice. I recommend contacting the manufacturer of your motor driver to see if they have any suggestions.