#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

#define IR1_PIN 2
#define IR2_PIN 3
#define IR3_PIN 4
#define IR4_PIN 5

bool ir1_detected = false;
bool ir2_detected = false;
bool ir3_detected = false;
bool ir4_detected = false;

void setup() 
{
  Serial.begin(9600);
  lcd.init();                      
  lcd.backlight(); 

  pinMode(IR1_PIN, INPUT_PULLUP);
  pinMode(IR2_PIN, INPUT_PULLUP);
  pinMode(IR3_PIN, INPUT_PULLUP);
  pinMode(IR4_PIN, INPUT_PULLUP);
}

void loop() 
{
  ir1_detected = digitalRead(IR1_PIN) == LOW;
  ir2_detected = digitalRead(IR2_PIN) == LOW;
  ir3_detected = digitalRead(IR3_PIN) == LOW;
  ir4_detected = digitalRead(IR4_PIN) == LOW;

  if (ir1_detected && ir2_detected) 
  {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Train Arrived");
    delay(2000);
  }

  if (ir3_detected && ir4_detected) 
  {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Train Departed");
    delay(2000);
  }

  if (ir1_detected && ir3_detected) 
  {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Possible Train Collision!");
    delay(2000);
  }

  if (ir4_detected && !ir3_detected) 
  {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Possible Train Collision!");
    delay(2000);
  }
}