RFID Door lock System RC522 with Arduino

sketch

#include <SPI.h>

#include <MFRC522.h>

 #define SS_PIN 5

#define RST_PIN 9

#define RELAY 3 //connect the relay to number 3 pin

#define BUZZER 2 // connect the buzzer to 2 pin

#define ACCESS_DELAY 2000

#define DENIED_DELAY 1000

MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance.

void setup() 

{

  Serial.begin(9600);   // Initiate a serial communication

  SPI.begin();          // Initiate  SPI bus

  mfrc522.PCD_Init();   // Initiate MFRC522

  pinMode(RELAY, OUTPUT);

  pinMode(BUZZER, OUTPUT);

  noTone(BUZZER);

  digitalWrite(RELAY, HIGH);

  Serial.println("Put your card to the reader for scanning ...");

  Serial.println();

}

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) == "61 48 93 25") // Ramesh New Emirtes ID Acces Allowed.

  {

    Serial.println("Authorized access");

    Serial.println();

    delay(500);

    digitalWrite(RELAY, LOW);

    delay(ACCESS_DELAY);

    digitalWrite(RELAY, HIGH);

    

  }

 

 else   {

    Serial.println(" Access denied");

    tone(BUZZER, 300);

    delay(DENIED_DELAY);

    noTone(BUZZER);

  }

} 

-----------------------------------------------------------------------------------------------------------------------------circuit diagram