#define BTN_PIN 2
byte directionPin = 8;
byte stepPin = 9;
int numberOfSteps = 3200;
byte ledPin = LED_BUILTIN;
int pulseWidthMicros = 20;
int millisbetweenSteps = 500;

void setup() {
  Serial.begin(9600);
  Serial.println("Starting StepperTest");
  Serial.println("Click Red Button");
  digitalWrite(ledPin, LOW);
  pinMode(directionPin, OUTPUT);
  pinMode(stepPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(BTN_PIN, INPUT_PULLUP);
  // MS1
  digitalWrite(11, HIGH);
  // MS2
  digitalWrite(12, HIGH);
  // MS3
  digitalWrite(13, HIGH);
}

void loop() {
  if (digitalRead(BTN_PIN) == LOW) {
    digitalWrite(directionPin, HIGH);
    for (int n = 0; n < numberOfSteps; n++) {
      digitalWrite(stepPin, HIGH);
      delayMicroseconds(pulseWidthMicros);
      digitalWrite(stepPin, LOW);
      delayMicroseconds(millisbetweenSteps);
      digitalWrite(ledPin, !digitalRead(ledPin));
    }
    delay(1000);
    digitalWrite(directionPin, LOW);
    for (int n = 0; n < numberOfSteps; n++) {
      digitalWrite(stepPin, HIGH);
      delayMicroseconds(pulseWidthMicros);
      digitalWrite(stepPin, LOW);
      delayMicroseconds(millisbetweenSteps);
      digitalWrite(ledPin, !digitalRead(ledPin));
    }
  }
}