#include <Servo.h>
Servo servosatu;
long jarak,waktu;

void setup() {
  // put your setup code here, to run once:
pinMode(13, OUTPUT);
pinMode(12, INPUT);
servosatu.attach(11);
Serial.begin(9600);
}

void loop() {
digitalWrite(13, LOW);
delayMicroseconds(2);
digitalWrite(13, HIGH);
delayMicroseconds(10);
digitalWrite(13, LOW);

waktu=pulseIn(12, HIGH);
jarak=0.034/2*waktu;

if(jarak<20) {
  servosatu.write(180);
  delay(1000);
}
if(jarak>20) {
  servosatu.write(0);
  delay(1000);
}

Serial.println(jarak);
}