#include <Servo.h>
Servo servo;
int angle=0;
int direction=1;
void setup() {
  // put your setup code here, to run once:
  servo.attach(11);
}

void loop() {
  // put your main code here, to run repeatedly:
    if(angle<0){
      angle =0;
      direction=1;
    }
    if(angle>180){
      angle=180;
      direction=-1;
    }
    angle +=direction;
    servo.write(angle);
    delay(5);
}