const int stepPin = 3;
const int dirPin  = 4;
const int swPin   = 2;

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

  
  digitalWrite(dirPin, LOW);
}

void loop() {

  
  if (digitalRead(swPin) == LOW) {
    digitalWrite(dirPin, HIGH);   // CW
  } else {
    digitalWrite(dirPin, LOW);    // CCW
  }

  // Один шаг
  digitalWrite(stepPin, HIGH);
  delayMicroseconds(800);
  digitalWrite(stepPin, LOW);
  delayMicroseconds(800);
}