#define stepPin 5
#define dirPin 4

void setup() {
  pinMode(stepPin, OUTPUT);
  pinMode(dirPin, OUTPUT);

  // Set the motor direction (HIGH = one direction, LOW = the other)
  digitalWrite(dirPin, HIGH);

}

void loop() {
  digitalWrite(dirPin,HIGH);
  for (int a=1;a<=400;a++)
  {
    digitalWrite(stepPin, HIGH);
    delayMicroseconds(10000);
    digitalWrite(stepPin,LOW);
    delayMicroseconds(10000);
  }
  digitalWrite(dirPin,LOW);
  for (int a=400;a>=1;a--)
  {
    digitalWrite(stepPin, HIGH);
    delayMicroseconds(10000);
    digitalWrite(stepPin,LOW);
    delayMicroseconds(10000);
  }
}