#define trig 15
#define echo 2
#define buzz 23

void setup() {
  Serial.begin(115200);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(5, OUTPUT);
  pinMode(18, OUTPUT);
  pinMode(19, OUTPUT);
  pinMode(21, OUTPUT);
  pinMode(23, OUTPUT);
}

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

void loop() {
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);
  int durasi = pulseIn(echo, HIGH);
  float distance = durasi * 0.034 / 2; 
   
   if((distance < 100) && (distance >= 50)) {
    digitalWrite(19, LOW);
    digitalWrite(18, LOW);
    digitalWrite(5, LOW);
    digitalWrite(21, HIGH);
    digitalWrite(buzz, LOW);
   }else if((distance < 200) && (distance >=100)){
    digitalWrite(19, HIGH);
    digitalWrite(18, LOW);
    digitalWrite(5, LOW);
    digitalWrite(21, HIGH);
    digitalWrite(buzz, LOW);
   }else if((distance < 300 ) && (distance >= 200)){
    digitalWrite(19, HIGH);
    digitalWrite(18, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(21, HIGH);
    digitalWrite(buzz, LOW);
   }else if(distance >= 300){
    digitalWrite(19, HIGH);
    digitalWrite(18, HIGH);
    digitalWrite(5, HIGH);
    digitalWrite(21, HIGH);
    digitalWrite(buzz, HIGH);
   }else{
    digitalWrite(19, LOW);
    digitalWrite(18, LOW);
    digitalWrite(5, LOW);
    digitalWrite(21, LOW);
    digitalWrite(buzz, LOW);
   }
      
}