#include <Servo.h>  

Servo myServo;  // create servo object

void setup() {
  myServo.attach(9); // attach servo to pin 9
}

void loop() {
  // Move servo from 0° to 180° in steps
  for (int pos = 0; pos <= 180; pos += 10) {
    myServo.write(pos);      // set servo position
    delay(500);              // wait for servo to reach
  }

  // Move servo back from 180° to 0°
  for (int pos = 180; pos >= 0; pos -= 10) {
    myServo.write(pos);
    delay(500);
  }
}