const int trigPin = 9;
const int echoPin = 10;
const int ledPin = 13;

long duration;
float distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledPin, OUTPUT);

  Serial.begin(9600);
  Serial.println("Ultrasonic Sensor Initialized.");
}

void loop() {
  // Send ultrasonic pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

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

  // Read echo pulse duration
  duration = pulseIn(echoPin, HIGH);

  // Convert to distance (cm)
  distance = duration * 0.034 / 2;

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

  // Check if object is too close
  if (distance < 10) {
    digitalWrite(ledPin, HIGH); // Turn on LED
  } else {
    digitalWrite(ledPin, LOW);  // Turn off LED
  }

  delay(500); // Delay for stability
}