About

This is a simple bi-polar stepper motor driver with Arduino compatible ATmega328P and STMicroelectronics's L6470 stepper driver chip.

Circuit

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;

https://docs.google.com/spreadsheets/d/1RQAgoJGYAUAYxNAMqekGk8QEkN-P5r_IoJqcyyNFA90/edit#gid=1711452351

Firmware

Arduino Bootloader :

"Minimum circuit" configuration in this link;

https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard

Arduino Sketch :

https://github.com/kanta/OneKnobStepper/blob/master/OneKnobStepper.ino

You should adjust "maxSpeed" val, depends on the motor and input voltage.