#include <SPI.h>
#include <MFRC522.h>
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C MyLCD(0x27, 20, 4); // Creates I2C LCD Object With (Address=0x27, Cols=20, Rows=4)
 
#define SS_PIN 10
#define RST_PIN 9
MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance.
 
void setup() 
{
  Serial.begin(9600);   // Initiate a serial communication
  MyLCD.init();
  MyLCD.backlight();

  SPI.begin();      // Initiate  SPI bus
  mfrc522.PCD_Init();   // Initiate MFRC522
  Serial.println("RFID Based Passport Scan Your Card ");
 // Serial.println();
  Serial.println("Scan your card to the RFID reader...");
  Serial.println();

  MyLCD.setCursor(0, 0);
  MyLCD.print("RFID Based Passport ");
  MyLCD.setCursor(0, 1);
  MyLCD.print("   Scan Your Card ");
  MyLCD.setCursor(0, 2);
  MyLCD.print(" To The RFID Reader.");

}
void loop() 
{
  // Look for new cards
  if ( ! mfrc522.PICC_IsNewCardPresent()) 
  {
    return;
  }
  // Select one of the cards
  if ( ! mfrc522.PICC_ReadCardSerial()) 
  {
    return;
  }
  //Show UID on serial monitor
  Serial.print("UID tag :");
  String content= "";
  byte letter;
  for (byte i = 0; i < mfrc522.uid.size; i++) 
  {
     Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
     Serial.print(mfrc522.uid.uidByte[i], HEX);
     content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
     content.concat(String(mfrc522.uid.uidByte[i], HEX));
  }
  Serial.println();
  Serial.print("Message : ");
  content.toUpperCase();
  if (content.substring(1) == "BD 31 15 2B") //change here the UID of the card/cards that you want to give access
  {
    Serial.println("Authorized access");
    Serial.println();
    delay(3000);
  }
 
 else   {
    Serial.println(" Access denied");
    delay(3000);
  }
}