const int trigPin = 15;   // Pin Trigger sensor ultrasonik
const int echoPin = 2;   // Pin Echo sensor ultrasonik
const int greenLedPin = 13; // Pin untuk lampu hijau
const int yellowLedPin = 12; // Pin untuk lampu kuning
const int redLedPin = 14; // Pin untuk lampu merah
const int BUZERPIN =26;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(yellowLedPin, OUTPUT);
  pinMode(redLedPin, OUTPUT);
  pinMode(BUZERPIN, OUTPUT);

  Serial.begin(9600);
  }

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW); 
                        
  long duration = pulseIn(echoPin, HIGH);
  long distance = duration * 0.034 / 2;
  Serial.print("Jarak: ");
  Serial.print(distance);
  Serial.println("CM");
  
  if (distance > 200) {
  digitalWrite(greenLedPin, LOW);
  digitalWrite(yellowLedPin, LOW);
  digitalWrite(redLedPin, HIGH);
  tone(26, 400, 500); 
  } 
  else if (distance > 100) {
  digitalWrite(greenLedPin, LOW);
  digitalWrite(yellowLedPin, HIGH);
  digitalWrite(redLedPin, LOW);
  tone(26, 225, 250); 
  } 
  else if (distance > 0) {
  digitalWrite(greenLedPin, HIGH);
  digitalWrite(yellowLedPin, LOW);
  digitalWrite(redLedPin, LOW);
  tone(26, 100, 250); 
  
  }                                                                       
  delay(600); // Interval pengukuran jarak
  }