void setup() {
  Serial.begin(9600);
  pinMode(2, OUTPUT);
  pinMode(3, INPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
}

void loop() {
  //mengaktifkan pin trigger
  digitalWrite(2, HIGH);
  delayMicroseconds(10);
  digitalWrite(2, LOW);

  //mengaktifkan pin echo
  long rentang = pulseIn(3, HIGH);

  //rumus mengukur jarak (CM)
  int jarak = rentang / 58;

  Serial.println(jarak);

  //kondisi led
  if(jarak >= 0 && jarak <= 100) {
    digitalWrite(12, HIGH);
    digitalWrite(11, LOW);
    digitalWrite(10, LOW);
  }
  else if(jarak >= 101 && jarak <= 200) {
    digitalWrite(11, HIGH);
    digitalWrite(12, LOW);
    digitalWrite(10, LOW);
  }
  else if(jarak >= 201 && jarak <= 400) {
    digitalWrite(10, HIGH);
    digitalWrite(12, LOW);
    digitalWrite(11, LOW);
  }
}