const int trigPin1 = 13;  // First ultrasonic sensor trigger pin
const int echoPin1 = 12;  // First ultrasonic sensor echo pin
const int trigPin2 = 9;   // Second ultrasonic sensor trigger pin
const int echoPin2 = 8;   // Second ultrasonic sensor echo pin
const int trigPin3 = 5;  // Third ultrasonic sensor trigger pin
const int echoPin3 = 4;  // Third ultrasonic sensor echo pin
const int trigPin4 = 1 ;  // Fourth ultrasonic sensor trigger pin
const int echoPin4 = 0;  // Fourth ultrasonic sensor echo pin


const int led1 = 11;      // First LED pin (Red)
const int led2 = 10;      // Second LED pin (Green)
const int led3 = 7;       // Third LED pin (Red)
const int led4 = 6;       // Fourth LED pin (Green)
const int led5 = 2;       // Fifth LED pin (Green)
const int led6 = 3;       // Sixth LED pin (Red)
const int led7 = A5;       // Seventh LED pin (Green)
const int led8 = A4;       // Eighth LED pin (Red)

void setup() {
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);
  pinMode(trigPin3, OUTPUT);
  pinMode(echoPin3, INPUT);
  pinMode(trigPin4, OUTPUT);  // New ultrasonic sensor trigger pin
  pinMode(echoPin4, INPUT);   // New ultrasonic sensor echo pin
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(led5, OUTPUT);
  pinMode(led6, OUTPUT);
  pinMode(led7, OUTPUT);  // New LED pin (Green)
  pinMode(led8, OUTPUT);  // New LED pin (Red)
  Serial.begin(9600);
}

void loop() {
  // Measure distance using the first ultrasonic sensor
  int distance1 = getDistance(trigPin1, echoPin1);

  // Measure distance using the second ultrasonic sensor
  int distance2 = getDistance(trigPin2, echoPin2);

  // Measure distance using the third ultrasonic sensor
  int distance3 = getDistance(trigPin3, echoPin3);

  // Measure distance using the fourth ultrasonic sensor
  int distance4 = getDistance(trigPin4, echoPin4);

  Serial.print("Distance 1: ");
  Serial.print(distance1);
  Serial.println(" cm");

  Serial.print("Distance 2: ");
  Serial.print(distance2);
  Serial.println(" cm");

  Serial.print("Distance 3: ");
  Serial.print(distance3);
  Serial.println(" cm");

  Serial.print("Distance 4: ");
  Serial.print(distance4);
  Serial.println(" cm");

  // Control LEDs based on the smallest distance among all sensors
  int smallestDistance = min(min(distance1, distance2), min(distance3, distance4));

  // Turn off all LEDs first
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  digitalWrite(led4, LOW);
  digitalWrite(led5, LOW);
  digitalWrite(led6, LOW);
  digitalWrite(led7, LOW);
  digitalWrite(led8, LOW);

  // Turn on the corresponding LEDs based on the smallest distance
  if (smallestDistance == distance1) {
    digitalWrite(led2, HIGH);  // Turn on First Green LED
  } else if (smallestDistance == distance2) {
    digitalWrite(led4, HIGH);  // Turn on Second Green LED
  } else if (smallestDistance == distance3) {
    digitalWrite(led5, HIGH);  // Turn on Third Green LED
  } else if (smallestDistance == distance4) {
    digitalWrite(led7, HIGH);  // Turn on Seventh Green LED
  }

  // Turn on Red LEDs for other sensors
  if (smallestDistance != distance1) {
    digitalWrite(led1, HIGH);  // Turn on First Red LED
  }
  if (smallestDistance != distance2) {
    digitalWrite(led3, HIGH);  // Turn on Second Red LED
  }
  if (smallestDistance != distance3) {
    digitalWrite(led6, HIGH);  // Turn on Third Red LED
  }
  if (smallestDistance != distance4) {
    digitalWrite(led8, HIGH);  // Turn on Eighth Red LED
  }

  delay(500); // Add a delay to avoid rapid switching
}

int getDistance(int trigPin, int echoPin) {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  return pulseIn(echoPin, HIGH) * 0.034 / 2;
}