stepper-unipolar-half-step.ard.cpp

#include <Arduino.h>

int current_pos   = 7;
int motor_speed   = 20;
int motor_pins[4] = { 9, 6, 7, 8 };
bool positions[8][4] = {
  { 1, 0, 0, 0 },
  { 1, 1, 0, 0 },
  { 0, 1, 0, 0 },
  { 0, 1, 1, 0 },
  { 0, 0, 1, 0 },
  { 0, 0, 1, 1 },
  { 0, 0, 0, 1 },
  { 1, 0, 0, 1 }
};


void led( bool state ) {
  digitalWrite( 13, state );
}


void setup() {
  Serial.begin( 115200 );
  for ( int i = 0; i < 4; i++ ) {
    pinMode( motor_pins[i], OUTPUT );
  }
}


void motor_move( int pos, int steps = 1 ) {
  if ( pos > 7 ) pos = 7;
  if ( pos < 0 ) pos = 0;
  for ( int i = 0; i < ( steps + 1 ); i++ ) {
    led( 1 );
    for ( int ii = 0; ii <4 ; ii++ ) {
      digitalWrite( motor_pins[ii], positions[pos][ii] );
    }
    delay( motor_speed );
    led( 0 );
  }
}


void loop() {
  if ( Serial.available() > 0 ) {
    int key_pressed = Serial.read();
    bool move = 0;
    if ( key_pressed == 67 ) {
      current_pos++;
      if ( current_pos > 7 ) {
        current_pos = 0;
      }
      move = 1;
    }
    if ( key_pressed == 68 ) {
      current_pos--;
      if ( current_pos < 0 ) {
        current_pos = 7;
      }
      motor_move( current_pos, 1 );
      move = 1;
    }
    if ( move ) {
      motor_move( current_pos, 1 );
      Serial.println( current_pos );
    }
  }
}