I’ve put together a circuit using an A4988 driver to drive a 2.8V 1.68A/phase stepper. I’m using an Arduino to run it and a 12V, 6A power supply. I’m trying to use 1/16 microstepping and run the motor at 3 rpm. I want to use microstepping to smooth out the movement. I set the current limit by measuring VREF to as close I can to 0.672V. (0.672 * 2.5 = 1.68)
The problem I’m running into is that microstepping isn’t moving the motor. I can hear the motor pulsing with each microstep, but it only moves when it hits the full step. I’ve read the data sheet for the driver and I realize torque drops significantly at 1/16 microstepping. Would it possibly fix my problem by changing to 1/8 or 1/4 microstepping? Would a different current limit setting help? Any other thoughts of what I could try?
Any suggestions would be appreciated.