#include <Servo.h> // servo library
#include <LiquidCrystal.h>

LiquidCrystal lcd(12,11,10,9,8,7); // LCD library
Servo s1, s2 ,s3,s4;
const int GREEN_LED = 4; // green LED pin
const int RED_LED = 6; // red LED pin
const int YELLOW_LED = 2; // red LED pin
const int BUZZER =  3; // buzzer pin
int irSensor1Pin = A0;
int irSensor2Pin = A1;
int irSensor3Pin = A2;
int val = 0;//Train Departure
int va2 = 0;//Train Arrival
int va3 = 0;//Obstacle detection

void setup() {
  Serial.begin(9600); // sensor buart rate
  pinMode(irSensor1Pin, INPUT); // IR sensor 1
  pinMode(irSensor2Pin, INPUT); // IR sensor 2
  pinMode(irSensor3Pin, INPUT); // IR sensor 3 Obstacle
  pinMode(GREEN_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(YELLOW_LED, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  s1.attach(A3); // Servo Connect 9 pin
  s2.attach(A4); // Servo Connect 9 pin
  s3.attach(A5); // Servo Connect 9 pin
  s4.attach(13); // Servo Connect 9 pin
  s1.write(0);
  s2.write(0);
  s3.write(0);
  s4.write(0);
}

void loop() {
  val = digitalRead(irSensor1Pin); // IR sensor 1 output pin connected
  va2 = digitalRead(irSensor2Pin); // IR sensor 2 output pin connected
  va3 = digitalRead(irSensor3Pin); // IR sensor 2 output pin connected
  Serial.println(val); // see the value in serial monitor in Arduino IDE
  Serial.println(va2); // see the value in serial monitor in Arduino IDE
  delay(200); // Time Delay
  if (va3 == 1) {//ARRIVAL OF the train
    s1.write(0); // SERVO 0 DEGREE
    s2.write(0);
    s3.write(0);
    s4.write(0);
      lcd.begin(16, 2);
      lcd.print("Train Coming:");
      
      digitalWrite(RED_LED, LOW);
      digitalWrite(BUZZER, LOW);
      digitalWrite(YELLOW_LED, LOW);
      digitalWrite(GREEN_LED, HIGH); 
      delay(2000);
  }
 
  if (va3 == 1&& va2==1 && val == 1) {//IF the trained arrived and No obstacle detected
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(RED_LED, LOW);
    digitalWrite(YELLOW_LED, HIGH);
    
    delay(2000);
    s1.write(90); // SERVO 90 DEGREE
    s2.write(90);
    s3.write(90);
    s4.write(90);
    lcd.begin(16, 2);
    lcd.print("No Object: Train Com");
    delay(2000);
    digitalWrite(BUZZER, HIGH);
    delay(2000);
    digitalWrite(BUZZER, LOW);
  }
  if (va3 == 1&& va2==0 && val == 1); { //IF the trained arrived and obstacle detected
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(RED_LED, HIGH);
    digitalWrite(YELLOW_LED, LOW);
    delay(2000);
    lcd.print("Detected: WAIT");
    lcd.print(": CLEAR");
    delay(2000);
    lcd.print(": CLEAR");
    s1.write(90); // SERVO 90 DEGREE
    s2.write(90);
    s3.write(90);
    s4.write(90);
    lcd.begin(16, 2);
    digitalWrite(BUZZER, HIGH);
    delay(2000);
    digitalWrite(BUZZER, LOW);
}
if (va3 == 0&& va2==1 && val == 1) { //IF obstacle detected and no train
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(RED_LED, LOW);
    digitalWrite(YELLOW_LED, LOW);
    delay(2000);
    lcd.print("Remain Open");
    delay(2000);
    s1.write(90); // SERVO 90 DEGREE
    s2.write(90);
    s3.write(90);
    s4.write(90);
    lcd.begin(16, 2);
    digitalWrite(BUZZER, LOW);
    delay(2000);
    digitalWrite(BUZZER, LOW);
}if (va3 == 0&& va2==0 && val == 1) { //IF no obstacle detected and no train
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(RED_LED, LOW);
    digitalWrite(YELLOW_LED, LOW);
    delay(2000);
    lcd.print("Remain Open");
    delay(2000);
    s1.write(90); // SERVO 90 DEGREE
    s2.write(90);
    s3.write(90);
    s4.write(90);
    lcd.begin(16, 2);
    digitalWrite(BUZZER, LOW);
    delay(2000);
    digitalWrite(BUZZER, LOW);
}
  if (val == 1) {//DEPARTURE OF the train
    s1.write(0); // SERVO 0 DEGREE
    s2.write(0);
    s3.write(0);
    s4.write(0);
      lcd.begin(16, 2);
      lcd.print("DEPARTED:");
      delay(2000);
      digitalWrite(RED_LED, LOW);
      digitalWrite(BUZZER, LOW);
      digitalWrite(YELLOW_LED, LOW);
      digitalWrite(GREEN_LED, HIGH); 
      delay(2000);
  }
 
}