Home Interface Projects MFRC522 RFID Reader with Arduino example

MFRC522 RFID Reader with Arduino example

by shedboy71

In this example we will show how to connect a RFID_RC522 module to an Arduino, the code example could be used as the basis of some sort of security/home automation system as the purpose of it is to check the ID of the card and depending on what is read a message will be displayed depending ona  positive or negative result. In real life this could be used to open a lock.

This is a typical module that you can buy quite easily

Iy usually comes with one contactless card and a key fob.

Pin Connection

This is the pin connections from the module to your Arduino

Module Pin Arduino Uno
SDA Digital 10
SCK Digital 13
MOSI Digital 11
MISO Digital 12
IRQ N/A
GND GND
RST Digital 9
3.3V 3.3V

 

Schematic

This is a schematic showing this connection above

Code

This requires the following library –  https://github.com/miguelbalboa/rfid

#include <SPI.h>
#include <MFRC522.h>
 
#define SS_PIN 10
#define RST_PIN 9
MFRC522 mfrc522(SS_PIN, RST_PIN);
 
void setup() 
{
  Serial.begin(9600);
  SPI.begin(); 
  mfrc522.PCD_Init();
  Serial.println("Place your card on the reader.");
}
 
void loop() 
{
  if ( ! mfrc522.PICC_IsNewCardPresent()) 
  {
    return;
  }
  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) == "D5 04 C4 AF") //change here to the UID of the card you have
  {
    Serial.println("Authorized");
    Serial.println();
    delay(3000);
  }
  else   
  {
    Serial.println("Access denied");
    delay(3000);
  }
}

 

Links

You can pick up one of these for about $2
Free Shipping RFID module RC522 Kits S50 13.56 Mhz 6cm With Tags SPI Write & Read for arduno uno 2560

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