const int trigPin = 5;
const int echoPin = 18;

#define sound_speed 0.034
#define cm_to_inch 0.393701
#define hijau 12
#define kuning 14
#define orange 4
#define merah 2

long duration;
float distanceCm;
float distanceInch;

void setup(){
  Serial.begin(115200);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(hijau, OUTPUT);
  pinMode(kuning, OUTPUT);
  pinMode(orange, OUTPUT);
  pinMode(merah, OUTPUT);
}

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

  duration = pulseIn(echoPin, HIGH);
  distanceCm = duration * sound_speed/2 + 0.06;
  distanceInch = distanceCm * cm_to_inch;
  Serial.print("Jarak (cm): ");
  Serial.print(distanceCm);
  digitalWrite(hijau, LOW);
  digitalWrite(kuning, LOW);
  digitalWrite(orange, LOW);
  digitalWrite(merah, LOW);
  
  if(distanceCm > 180){
    Serial.println(" = AMAN");
    digitalWrite(hijau, HIGH);
  }
  else if(distanceCm > 150 && distanceCm < 180){
    Serial.println(" = Siaga 1 !");
    digitalWrite(kuning, HIGH);
  }
  else if(distanceCm > 120 && distanceCm < 150){
    Serial.println(" = Siaga 2 !!");
    digitalWrite(orange, HIGH);
  }
  else if(distanceCm < 120){
    Serial.println(" = Siaga 3 !!!");
    digitalWrite(merah, HIGH);
  }

  delay(1000);
}