This is a simple bi-polar stepper motor driver with Arduino compatible ATmega328P and STMicroelectronics's L6470 stepper driver chip.
Power supply for AVR is come from L6470's internal voltage regulator (3V). Clock is internal 8MHz RC oscillator.
These are optional PCB foot print:
- a switch input for L6470
- an external xtal for L6470
- 2 trimmer for AVR
- an external xtal for AVR
Also unused pins are exposed as pin pads on PCB.
DC input voltage range is 9V to 32V, the chemical capacitor in this circuit has voltage limit 35V.
A components list is available from here;
Arduino Bootloader :
"Minimum circuit" configuration in this link;
Arduino Sketch :
You should adjust "maxSpeed" val, depends on the motor and input voltage.