#define ECHO_PIN 2
#define TRIG_PIN 15
#define led1 4
#define led2 5
#define led3 18
#define led4 19
#define buzzer 13

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(buzzer, OUTPUT);
}

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

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  float distance = duration * 0.034 / 2;

  Serial.print("Jarak:");
  Serial.println(distance);
  //delay(100);

  if(distance>300){
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, HIGH);
    tone(buzzer,150);
    delay(200);
    noTone(buzzer);
    delay(100);
  }
  else if (distance>200){
   digitalWrite(led1, HIGH);
   digitalWrite(led2, HIGH);
   digitalWrite(led3, HIGH);
   digitalWrite(led4, LOW); 
  }
  else if (distance>100){
   digitalWrite(led1, HIGH);
   digitalWrite(led2, HIGH);
   digitalWrite(led3, LOW);
   digitalWrite(led4, LOW);   
  }
  else if (distance>50){
   digitalWrite(led1, HIGH);
   digitalWrite(led2, LOW);
   digitalWrite(led3, LOW);
   digitalWrite(led4, LOW);  
  }
  else{
   digitalWrite(led1, LOW);
   digitalWrite(led2, LOW);
   digitalWrite(led3, LOW);
   digitalWrite(led4, LOW); 
  }
delay(100);
 }