// Define pins for the first ultrasonic sensor
const int trigPin1 = 2;
const int echoPin1 = 3;
const int ledPin1 = 4;

// Define pins for the second ultrasonic sensor
const int trigPin2 = 5;
const int echoPin2 = 6;
const int ledPin2 = 7;

// Define pins for the third ultrasonic sensor
const int trigPin3 = 8;
const int echoPin3 = 9;
const int ledPin3 = 10;

// Define pins for the fourth ultrasonic sensor
const int trigPin4 = 11;
const int echoPin4 = 12;
const int ledPin4 = 13;

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

  // Define pin modes
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
  pinMode(ledPin1, OUTPUT);

  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);
  pinMode(ledPin2, OUTPUT);

  pinMode(trigPin3, OUTPUT);
  pinMode(echoPin3, INPUT);
  pinMode(ledPin3, OUTPUT);

  pinMode(trigPin4, OUTPUT);
  pinMode(echoPin4, INPUT);
  pinMode(ledPin4, OUTPUT);
}

void loop() {
  // Measure distance and control LED for sensor 1
  measureAndControlLED(trigPin1, echoPin1, ledPin1);

  // Measure distance and control LED for sensor 2
  measureAndControlLED(trigPin2, echoPin2, ledPin2);

  // Measure distance and control LED for sensor 3
  measureAndControlLED(trigPin3, echoPin3, ledPin3);

  // Measure distance and control LED for sensor 4
  measureAndControlLED(trigPin4, echoPin4, ledPin4);
}

// Function to measure distance and control LED for a sensor
void measureAndControlLED(int trigPin, int echoPin, int ledPin) {
  long duration;
  int distance;

  // Clear the trigger pin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  // Send 10 microsecond pulse to trigger pin
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

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

  // Calculate the distance in centimeters
  distance = duration * 0.034 / 2;

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

  // Check if distance is less than or equal to 10
  if (distance <= 10) {
    // Turn on LED
    digitalWrite(ledPin, HIGH);
  } else if (distance >= 50) {
    // Turn off LED
    digitalWrite(ledPin, LOW);
  }
}