#include <Servo.h>
Servo myServo;
int pos;

void setup() {
  // put your setup code here, to run once:
  myServo.attach(9);
}

void loop() {
  // put your main code here, to run repeatedly:
  for(pos=0;pos<=180;pos+=1){
    myServo.write(pos);
    delay(15);
  }
  for(pos=180;pos>=0;pos-=1){
    myServo.write(pos);
    delay(15);
  }
}