const int trigPin = 9;
const int echoPin = 10;
const int ledHijau = 6;
const int ledMerah = 7;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledHijau, OUTPUT);
  pinMode(ledMerah, OUTPUT);
  Serial.begin(9600);
}


void loop() {
  float distance = baca_jarak();
  
  Serial.print("Jarak: ");
  Serial.print(distance);
  Serial.println(" cm");

  if (distance > 20.0) {
    digitalWrite(ledHijau, HIGH);
    digitalWrite(ledMerah, LOW);
  } else if (distance > 10.0) {
    digitalWrite(ledHijau, LOW);
    digitalWrite(ledMerah, HIGH);
  } else {
    digitalWrite(ledHijau, LOW);
    digitalWrite(ledMerah, HIGH);
    delay(200);
    digitalWrite(ledMerah, LOW);
    delay(200);
  }
  
  delay(500);
}

float baca_jarak() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  long duration = pulseIn(echoPin, HIGH);
  float distance = duration * 0.034 / 2.0; // Konversi waktu ke jarak dalam cm (menggunakan float)
  
  return distance;
}