#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);
  }
}