#include <Ultrasonic.h>

const int trigPin = 12;  // Trigger pin of the ultrasonic sensor
const int echoPin = 14;  // Echo pin of the ultrasonic sensor
const int redLedPin = 2;  // Red LED pin
const int yellowLedPin = 5;  // Yellow LED pin
const int greenLedPin = 4;  // Green LED pin

Ultrasonic ultrasonic(trigPin, echoPin);

void setup() {
  Serial.begin(115200);
  pinMode(redLedPin, OUTPUT);
  pinMode(yellowLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
}

void loop() {
  // Measure distance using the ultrasonic sensor
  int distance = ultrasonic.read();

  // Print distance to Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Check distance and control LEDs accordingly
  if (distance > 150) {
    digitalWrite(greenLedPin, HIGH);
    digitalWrite(yellowLedPin, LOW);
    digitalWrite(redLedPin, LOW);
  } else if (distance > 50 && distance <= 150) {
    digitalWrite(greenLedPin, LOW);
    digitalWrite(yellowLedPin, HIGH);
    digitalWrite(redLedPin, LOW);
  } else {
    digitalWrite(greenLedPin, LOW);
    digitalWrite(yellowLedPin, LOW);
    digitalWrite(redLedPin, HIGH);
  }

  delay(500);  // Add a small delay for stability
}