const int trigPin = 9;  // Trig pin of the ultrasonic sensor
const int echoPin = 10; // Echo pin of the ultrasonic sensor
const int led1Pin = 12; // Pin for the first LED
const int led2Pin = 13; // Pin for the second LED

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(led1Pin, OUTPUT);
  pinMode(led2Pin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // Trigger the ultrasonic sensor to send a 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);

  // Calculate the distance in centimeters (speed of sound is 343 m/s or 0.0343 cm/microsecond)
  int distance = duration * 0.0343 / 2;

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

  // Control LEDs based on the distance measured
  if (distance < 20) {
    // If the distance is less than 20 cm, turn on both LEDs
    digitalWrite(led1Pin, HIGH);
    digitalWrite(led2Pin, HIGH);
  } else {
    // If the distance is 20 cm or more, turn off both LEDs
    digitalWrite(led1Pin, LOW);
    digitalWrite(led2Pin, LOW);
  }

  // Wait for a short duration before taking the next measurement
  delay(1000);
}