#include <Stepper.h>

const int stepsPerRevolution = 100; 
Stepper myStepper(stepsPerRevolution, 18, 19, 21, 22);

void setup() {

  myStepper.setSpeed(60);
  Serial.begin(9600);
}

void loop() {

  Serial.println("90 derajat searah jarum jam");
  myStepper.step(stepsPerRevolution / 2);
  delay(500);

  Serial.println("180 derajat searah jarum jam");
  myStepper.step(stepsPerRevolution / 2);
  delay(500);

  Serial.println("Kembali ke 0 derajat");
  myStepper.step(-stepsPerRevolution / 1);
  delay(500);

  Serial.println("-180 derajat berlawanan jarum jam");
  myStepper.step(-stepsPerRevolution / 1);
  delay(500);

  Serial.println("Kembali ke 0 derajat");
  myStepper.step(stepsPerRevolution);
  delay(500);
}