const int redPin = 18;
const int yellowPin = 19;
const int greenPin = 17;
const int ultrasonicTrigPin = 4; // Replace with the actual pin connected to the trig pin of the ultrasonic sensor
const int ultrasonicEchoPin = 5; // Replace with the actual pin connected to the echo pin of the ultrasonic sensor

unsigned long crossingStartTime = 0;

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(ultrasonicTrigPin, OUTPUT);
  pinMode(ultrasonicEchoPin, INPUT);
  Serial.begin(9600); // Initialize serial communication
}

void loop() {
  // Ultrasonic sensor distance check
  int distance = getUltrasonicDistance();
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  if (distance < 30) {  // If a pedestrian is detected (adjust distance accordingly)
    if (crossingStartTime == 0) {
      crossingStartTime = millis();
    }
    pedestrianCrossing();
  } else {
    crossingStartTime = 0;  // Reset crossing start time
    normalTrafficLight();
  }
}

int getUltrasonicDistance() {
  digitalWrite(ultrasonicTrigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(ultrasonicTrigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(ultrasonicTrigPin, LOW);

  return pulseIn(ultrasonicEchoPin, HIGH) * 0.034 / 2;
}

void pedestrianCrossing() {
  // Green light for 30 seconds
  digitalWrite(redPin, LOW);
  digitalWrite(yellowPin, LOW);
  digitalWrite(greenPin, HIGH);
  
  if (millis() - crossingStartTime < 30000) {
    // Pedestrian crossing in progress
    // You can add additional actions or conditions here
  } else {
    // Pedestrian crossing completed
    crossingStartTime = 0;
    normalTrafficLight();
  }
}

void normalTrafficLight() {
  // State 1: Red light
  Serial.println("Red Light");
  digitalWrite(redPin, HIGH);
  digitalWrite(yellowPin, LOW);
  digitalWrite(greenPin, LOW);
  delay(6000);  // State 1 duration
  
  // State 2: Green light
  Serial.println("Green Light");
  digitalWrite(redPin, LOW);
  digitalWrite(yellowPin, LOW);
  digitalWrite(greenPin, HIGH);
  for (int i = 0; i < 3; i++) {
    delay(10000);  // State 2 duration
    digitalWrite(greenPin, LOW);
    delay(500);
    digitalWrite(greenPin, HIGH);
    delay(500);
  }
  
  // State 3: Orange light
  Serial.println("Orange Light");
  digitalWrite(redPin, LOW);
  digitalWrite(yellowPin, HIGH);
  digitalWrite(greenPin, LOW);
  for (int i = 0; i < 6; i++) {
    delay(1000);  // State 3 duration
    digitalWrite(yellowPin, LOW);
    delay(500);
    digitalWrite(yellowPin, HIGH);
    delay(500);
  }
}