void setup() {
  Serial.begin(9600);
  pinMode(13, OUTPUT);
  pinMode(12, INPUT);
  pinMode(7, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(2, OUTPUT);

}

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

 int rentang = pulseIn(12,HIGH);
 int jarak = (rentang/58);

 Serial.println(jarak);

  if(jarak >= 0 && jarak <= 100) {
    digitalWrite(7, HIGH);
    digitalWrite(4, LOW);
    digitalWrite(2, LOW);
  }
  
  else if(jarak >= 201 && jarak <= 400) {
    digitalWrite(2, HIGH);
    digitalWrite(7, LOW);
    digitalWrite(4, LOW);
  }

  else if(jarak >= 101 && jarak <= 200) {
    digitalWrite(4, HIGH);
    digitalWrite(7, LOW);
    digitalWrite(2, LOW);

  }

}