// Include the necessary libraries
#include <Arduino.h>

// Define the pins for the ultrasonic sensor
const int trigPin = 2;
const int echoPin = 4;

// Define the pin for the LED
const int ledPin = 14;

// Define the maximum distance in centimeters
const int maxDistance = 500;

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

  // Set the trigger pin as an output
  pinMode(trigPin, OUTPUT);
  
  // Set the echo pin as an input
  pinMode(echoPin, INPUT);

  // Set the LED pin as an output
  pinMode(ledPin, OUTPUT);
}

void loop() {
  // Trigger the ultrasonic sensor by sending a 10 microsecond pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure the duration of the pulse on the echo pin
  long duration = pulseIn(echoPin, HIGH);

  // Convert the duration to distance in centimeters
  int distance = duration * 0.034 / 2;

  // Print the distance to the serial monitor
  Serial.print("Distance: ");
  Serial.println(distance);

  // Check if the distance is greater than 300cm
  if (distance > 300) {
    // Turn on the LED
    digitalWrite(ledPin, HIGH);
  } else {
    // Turn off the LED
    digitalWrite(ledPin, LOW);
  }

  // Delay before taking the next measurement
  delay(1000);
}