// Define the pins for each traffic light
int trafficLight1[] = {4, 5, 6};   // {Red, Yellow, Green}
int trafficLight2[] = {7, 8, 9};   // {Red, Yellow, Green}
int trafficLight3[] = {A0, A1, A2};  // {Red, Yellow, Green}
int trafficLight4[] = {A3, A4, A5}; // {Red, Yellow, Green}

// Timings in milliseconds
const int yellowTime = 2000;   // Yellow light duration
const int Time = 5000;      // light duration for one cycle

// Ultrasonic sensor pins 
const int trigPin1 = 3;  // Trigger pin1
const int echoPin1 = 2;  // Echo pin1
const int trigPin2 = 11;  // Trigger pin2
const int echoPin2 = 10;  // Echo pin2

long duration ;
int distance1, distance2;

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

  // Set the trigger pin as an output and the echo pin as an input
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
   pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);

  // Initialize each pin as an output
  for (int i = 0; i < 3; i++) {
    pinMode(trafficLight1[i], OUTPUT);
    pinMode(trafficLight2[i], OUTPUT);
    pinMode(trafficLight3[i], OUTPUT);
    pinMode(trafficLight4[i], OUTPUT);
  }
}

void loop() {
  // Measure distance using the ultrasonic sensor
  measureDistance1();
  measureDistance2();

  // Print the distance on the serial monitor
  Serial.print("Distance1: ");
  Serial.print(distance1);
  Serial.println(" cm");
 Serial.print("Distance2: ");
  Serial.print(distance2);
  Serial.println(" cm");

  if ((distance1 > 5 && distance2 > 5) || (distance1 <= 5 && distance2 <= 5)) {
    // Traffic light 1 green, others red
    setTrafficLight(trafficLight1, LOW, LOW, HIGH);  // Green
    setTrafficLight(trafficLight2, LOW, LOW, HIGH);  // Green
    setTrafficLight(trafficLight3, HIGH, LOW, LOW);  // Red
    setTrafficLight(trafficLight4, HIGH, LOW, LOW);  // Red
    delay(Time);

    // Traffic light 1 yellow, others red
    setTrafficLight(trafficLight1, LOW, HIGH, LOW);  // Yellow
    setTrafficLight(trafficLight2, LOW, HIGH, LOW);  // Yellow
    setTrafficLight(trafficLight3, HIGH, LOW, LOW);  // Red
    setTrafficLight(trafficLight4, HIGH, LOW, LOW);  // Red
    delay(yellowTime);

    // Traffic light 1 red,
    setTrafficLight(trafficLight1, HIGH, LOW, LOW);  // Red
    setTrafficLight(trafficLight2, HIGH, LOW, LOW);  // Red
    setTrafficLight(trafficLight3, LOW, LOW, HIGH);  // GREEN
    setTrafficLight(trafficLight4, LOW, LOW, HIGH);  // GREEN
    delay(Time);

    // Traffic light 2 red, traffic light 3 green
    setTrafficLight(trafficLight1, HIGH, LOW, LOW);  // Red
    setTrafficLight(trafficLight2, HIGH, LOW, LOW);  // Red
    setTrafficLight(trafficLight3, LOW, HIGH, LOW);  // Yellow
    setTrafficLight(trafficLight4, LOW, HIGH, LOW);  // Yellow
    delay(yellowTime);
  }
  if ((distance1 <= 5 && distance2 > 5))
  {
    // If a vehicle is detected (distance <= 5 cm), all lights stay red except traffic light 1
    setTrafficLight(trafficLight1, LOW, LOW, HIGH);  // Green
    setTrafficLight(trafficLight2, LOW, LOW, HIGH);  // Green
    setTrafficLight(trafficLight3, HIGH, LOW, LOW);  // Red
    setTrafficLight(trafficLight4, HIGH, LOW, LOW);  // Red
  }
    if ((distance1 > 5 && distance2 <= 5))
  {
    // If a vehicle is detected (distance <= 5 cm), all lights stay red except traffic light 1
    setTrafficLight(trafficLight1, HIGH, LOW, LOW);  // red
    setTrafficLight(trafficLight2, HIGH, LOW, LOW);  // red
    setTrafficLight(trafficLight3, LOW, LOW, HIGH);  // Green
    setTrafficLight(trafficLight4, LOW, LOW, HIGH);  // Green
  }
}

void setTrafficLight(int light[], int red, int yellow, int green) {
  digitalWrite(light[0], red);
  digitalWrite(light[1], yellow);
  digitalWrite(light[2], green);
}

void measureDistance1() {
  // Clear the trigger pin
  digitalWrite(trigPin1, LOW);
  delayMicroseconds(2);

  // Set the trigger pin HIGH for 10 microseconds
  digitalWrite(trigPin1, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin1, LOW);

  // Read the echo pin and calculate the duration of the pulse
  duration = pulseIn(echoPin1, HIGH);

  // Calculate the distance in cm
  distance1 = duration * 0.034 / 2;
}

void measureDistance2() {
  // Clear the trigger pin
  digitalWrite(trigPin2, LOW);
  delayMicroseconds(2);

  // Set the trigger pin HIGH for 10 microseconds
  digitalWrite(trigPin2, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin2, LOW);

  // Read the echo pin and calculate the duration of the pulse
  duration = pulseIn(echoPin2, HIGH);

  // Calculate the distance in cm
  distance2 = duration * 0.034 / 2;
}