#define ECHO_PIN 15
#define TRIG_PIN 2
#define LED1 19
#define LED2 21
#define LED3 22
#define LED4 23
#define BUZZER 13

void setup() 
{
  Serial.begin(115200);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);
  pinMode(BUZZER, OUTPUT);
}

void loop() 
{
  //Menghasilkan Ultrasonic 40 KHz
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  //Baca Ultrasonic
  int duration = pulseIn(ECHO_PIN, HIGH);
  float distance = duration * 0.034 / 2;

  if(distance < 50.0)
  {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
    digitalWrite(LED4, LOW);
    noTone(BUZZER);  
  }
  else
  if(distance < 100.0)
  {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
    digitalWrite(LED4, LOW);
    noTone(BUZZER);       
  }
  else
  if(distance < 200.0)
  {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);
    digitalWrite(LED3, LOW);
    digitalWrite(LED4, LOW);
    noTone(BUZZER);       
  }
  else
  if(distance < 300.0)
  {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);
    digitalWrite(LED3, HIGH);
    digitalWrite(LED4, LOW);
    noTone(BUZZER);       
  }
  else
  {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);
    digitalWrite(LED3, HIGH);
    digitalWrite(LED4, HIGH);
    tone(BUZZER, 200);      
  }
  Serial.print("Jarak: ");
  Serial.println(distance);

  delay(100);
}