#define DIR_PIN 8
#define PUL_PIN 9

void setup(){
  pinMode(PUL_PIN, OUTPUT);
  pinMode(DIR_PIN, OUTPUT);
}

void loop(){

  // Initial direction
  digitalWrite(DIR_PIN, HIGH);

  for(int i=0;i<200;i++){
    digitalWrite(PUL_PIN, HIGH);
    delayMicroseconds(5000);
    digitalWrite(PUL_PIN, LOW);
    delayMicroseconds(5000);
  }

  delay(1000);

  // Opposite direction
  digitalWrite(DIR_PIN, LOW);

  for(int i=0;i<200;i++){
    digitalWrite(PUL_PIN, HIGH);
    delayMicroseconds(5000);
    digitalWrite(PUL_PIN, LOW);
    delayMicroseconds(5000);
  }

  delay(1000);
  
}

/*

  A4988 PINS

  ENA  o ---------- o  MOTOR VCC
  MS1  o            o  GROUND
  MS2  o            o  2B
  MS3  o            o  2A
  RST  o            o  1A
  SLP  o            o  1B
  STP  o            o  5V
  DIR  o ---------- o  GND

*/