#define merah 8
#define kuning 7
#define hijau 6
#define trig 3
#define echo 2

void setup() {
  Serial.begin(115200);
  pinMode(merah, OUTPUT);
  pinMode(kuning, OUTPUT);
  pinMode(hijau, OUTPUT);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);

}

float readDistanceCM(){
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);
  int duration = pulseIn(echo, HIGH);
  return duration * 0.034/2;
}

void loop() {
  float distance = readDistanceCM();

  if(distance <= 100){
    digitalWrite(merah, HIGH);
    digitalWrite(kuning, LOW);
    digitalWrite(hijau, LOW);
    Serial.println("Awas Banjir!");
  }
  else if(distance > 100 && distance <= 200){
    digitalWrite(merah, LOW);
    digitalWrite(kuning, HIGH);
    digitalWrite(hijau, LOW);
    Serial.println("waspada!");
  }
  if(distance > 200){
    digitalWrite(merah, LOW);
    digitalWrite(kuning, LOW);
    digitalWrite(hijau, HIGH);
    Serial.println("Aman, Silahkan Lewat");
  }
  delay(1000);
}