const int trigPin = 9;
const int echoPin = 10;
const int buzzerPin = 8;
const long distanceThreshold = 50; // Distance threshold in centimeters

void setup() {
  // Initialize serial communication
  Serial.begin(9600);

  // Set pin modes
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);

  // Initialize buzzer to off
  digitalWrite(buzzerPin, LOW);
}

void loop() {
  // Send a pulse to trigger the ultrasonic sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Read the echo pin and calculate the distance
  long duration = pulseIn(echoPin, HIGH);
  long distance = (duration * 0.034) / 2;

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

  // Turn on the buzzer if the distance is less than the threshold
  if (distance < distanceThreshold) {
    digitalWrite(buzzerPin, HIGH);
  } else {
    digitalWrite(buzzerPin, LOW);
  }

  // Wait for 500 milliseconds before the next reading
  delay(500);
}