#include <Servo.h>

Servo myServo; // Create a servo object

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

void loop() {
  for (int pos = 0; pos <= 180; pos++) { // Sweep from 0° to 180°
    myServo.write(pos);                 // Set servo position
    delay(15);                          // Wait for servo to reach position
  }
  for (int pos = 180; pos >= 0; pos--) { // Sweep back from 180° to 0°
    myServo.write(pos);
    delay(15);
  }
}