#define TRIG_PIN 9
#define ECHO_PIN 10
#define LED_PIN 13

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  long duration, distance;

 
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  
 
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
 
  duration = pulseIn(ECHO_PIN, HIGH);
  
 
  distance = (duration * 0.034) / 2;

 
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

 
  if (distance <= 1000) {
    digitalWrite(LED_PIN, HIGH);
  } else {
    digitalWrite(LED_PIN, LOW); 
  }

  delay(500);
}