#include <Servo.h>

Servo myServo;
int pos1 = 0;
int pos2 = 90;
int pos3 = 180;

void setup() {
  myServo.attach(3);
}

void loop() {
  // put your main code here, to run repeatedly:
  myServo.write(pos1);
  delay(1);
  myServo.write(pos2);
  delay(1);
  myServo.write(pos3);
  delay(1);
}