const int trigPin = 2;  // Trig pin of the ultrasonic sensor
const int echoPin = 3;  // Echo pin of the ultrasonic sensor
const int redLedPin = 4;  // Red LED pin
const int greenLedPin = 5;  // Green LED pin
const int buzzerPin = 6;  // Buzzer pin
void setup() {
  // put your setup code here, to run once:
 pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(redLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
 long duration, distance;

  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);

  distance = (duration * 0.0343) / 2;

  if (distance < 50) {
    digitalWrite(redLedPin, HIGH);
    digitalWrite(greenLedPin, LOW);
    tone(buzzerPin, 1000);  // Activate the buzzer
  } else {
    digitalWrite(redLedPin, LOW);
    digitalWrite(greenLedPin, HIGH);
    noTone(buzzerPin);  // Deactivate the buzzer
  }

  delay(1000);  // Adjust the delay as needed
}