#define TRIG_PIN 5
#define ECHO_PIN 18
#define GREEN_LED 17
#define ORANGE_LED 16
#define RED_LED 15

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(GREEN_LED, OUTPUT);
  pinMode(ORANGE_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);
  
  Serial.begin(9600);
}

void loop() {
  long duration;
  int distance;

  // Send a 10us pulse to trigger pin
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Read the echo pin and calculate distance
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2;  // Convert to centimeters

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  if (distance > 300) {
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(ORANGE_LED, LOW);
    digitalWrite(RED_LED, LOW);
  } else if (distance > 200 && distance <= 300) {
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(ORANGE_LED, HIGH);
    digitalWrite(RED_LED, LOW);
  } else if (distance <= 200) {
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(ORANGE_LED, LOW);
    digitalWrite(RED_LED, HIGH);
  }

  delay(500); // Delay for stability
}