// Define pins for ultrasonic sensor
const int trigPin = 12;
const int echoPin = 10;

// Define pins for buzzer
const int buzzerPin = 8;

// Define variable for duration of ultrasonic pulse
long duration;

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  
  // Set pin modes
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
}

void loop() {
  // Send ultrasonic pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Measure the duration of the pulse
  duration = pulseIn(echoPin, HIGH);
  
  // Calculate distance in cm
  int distance = duration * 0.034 / 2;
  
  // Print distance to serial monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  // If distance is less than 10 cm, sound the buzzer
  if (distance < 10) {
    digitalWrite(buzzerPin, HIGH);
  } else {
    digitalWrite(buzzerPin, LOW);
  }
  
  // Wait a short time before taking another reading
  delay(100);
}