#include <Servo.h>

Servo myServo;
int angle = 0;

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

void loop() {
  for (angle = 0; angle <= 180; angle += 1) {
    myServo.write(angle);  // Move servo to the current angle
    delay(20);
  }

  delay(1000);

  for (angle = 180; angle >= 0; angle -= 1) {
    myServo.write(angle);
    delay(20);
  }

  delay(1000);
}