RFID-LCD.ino

#include <SPI.h>
#include <MFRC522.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

 int led1=6;
 int led2=7;
 
#define RST_PIN 9
#define SS_PIN 10
 
byte readCard[4];
String MasterTag = "C920D9A3";  // REPLACE this Tag ID with your Tag ID!!!
String tagID = "";
 
// Create instances
MFRC522 mfrc522(SS_PIN, RST_PIN);

void setup() 
{
  lcd.begin();
  lcd.backlight();
  SPI.begin(); // SPI bus
  mfrc522.PCD_Init(); // MFRC522
   pinMode(led1,OUTPUT);
   pinMode(led2,OUTPUT);
 
  lcd.clear();
  lcd.print(" Access Control ");
  lcd.setCursor(0, 1);
  lcd.print("Scan Your Card>>");
}
 
void loop() 
{
    Serial.begin(9600);
  //Wait until new tag is available
  while (getID()) 
  {
    lcd.clear();
    lcd.setCursor(0, 0);
     
    if (tagID == MasterTag) 
    {
            
      lcd.print(" Access Granted!");
       digitalWrite(led1,HIGH); 
       digitalWrite(led2,LOW);
      // You can write any code here like opening doors, switching on a relay, lighting up an LED, or anything else you can think of.
    }
    else
    {
       digitalWrite(led2,HIGH); 
       digitalWrite(led1,LOW);  
      lcd.print(" Access Denied!");
       
    }
     
      lcd.setCursor(0, 1);
      lcd.print(" ID : ");
      lcd.print(tagID);
       
    delay(2000);
     digitalWrite(led2,LOW); 
     digitalWrite(led1,LOW);
    lcd.clear();
    lcd.print(" Access Control ");
    lcd.setCursor(0, 1);
    lcd.print("Scan Your Card>>");
  }
}
 
//Read new tag if available
boolean getID() 
{
  // Getting ready for Reading PICCs
  if ( ! mfrc522.PICC_IsNewCardPresent()) { //If a new PICC placed to RFID reader continue
  return false;
  }
  if ( ! mfrc522.PICC_ReadCardSerial()) { //Since a PICC placed get Serial and continue
  return false;
  }
  tagID = "";
  for ( uint8_t i = 0; i < 4; i++) { // The MIFARE PICCs that we use have 4 byte UID
  //readCard[i] = mfrc522.uid.uidByte[i];
  tagID.concat(String(mfrc522.uid.uidByte[i], HEX)); // Adds the 4 bytes in a single String variable
  }
  tagID.toUpperCase();
  mfrc522.PICC_HaltA(); // Stop reading
  return true;
}