stepper

stepper motor control via RPi

A4988 driver

wiring

GND 3-5.5V ground DIRECTION -> pi gpio VDD 3-5.5V logic power supply STEP 1B stepper coil 1 SLEEP --l 1A stepper coil 1 RESET --l 2A stepper coil 2 MS3 -> pi gpio 2B stepper coil 2 MS2 -> pi gpio GND 8-35V ground MS1 -> pi gpio VMOT 8-35V stepper power supply ENABLE -> pi gpio

current limiting

Find the two sense Resistors Rs1 and Rs2. They are usually on the same side of the pcb like the chip and have Values like 0.05 Ohm, 0.068 Ohm and 0.1 Ohm. Now measure the Reference Voltage without VMOT power supply but only power supply between the potientiometer and GND 3-5.5V. It should be `VREF = IMAX * 8 * Rs. And set it accordingly.