I have a unipolair arduino 5V stepper motor with gearbox, the motor is controlled through a ULN2003 driver. The arduino stepper motor knob example works ok.
The Pololu DRV8825 stepper motor driver is for bipolair stepper motors, can I use this stepper for a unipolair stepper motor?
What happens if I connect the 5th (and 6th) wire to 5V
I should have read the manual first.
Some unipolar stepper motors (e.g. those with six or eight leads) can be controlled by this driver as bipolar stepper motors. For more information, please see the frequently asked questions. Unipolar motors with five leads cannot be used with this driver.
As long as you use ONLY full step mode, five wire steppers will work with the driver. I have personally verified this. If all the windings have the same resistance, the center tap is always close to ground potential in full step mode, so just leave it open. Microstepping probably won’t work and so I didn’t try it.