#include <Servo.h>    // Add servo library

Servo myServo;        // Create servo variable

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

void loop() {
  myServo.write(180); // Turn servo to 180 degrees
  delay(1000);        // Wait 1 second
  myServo.write(0);   // Turn servo to 0 degrees
  delay(1000);        // Wait 1 second
}