Introduction

RFID (Radio-Frequency Identification) technology is widely used for various applications, including access control, inventory management, and tracking. In this guide, we’ll walk you through the process of reading RFID tags using the RC522 RFID module and an Arduino. By the end of this tutorial, you’ll be able to identify and retrieve data from RFID tags with ease.

Things we need

• Arduino Uno
• RFID Reader RC522
• RFID Cards / Tags
• Jumper cables
• Breadboard

Circuit diagram

Working of the system with Arduino

To interface with the RC522 module, we need to install the appropriate libraries in the Arduino IDE. Follow these steps:

1. Open the Arduino IDE.
2. Go to “Sketch” -> “Include Library” -> “Manage Libraries…”
3. In the Library Manager, type “MFRC522” into the search bar.
4. Click the “Install” button to install the “MFRC522” library by “GitHub Community.”

Code

Here’s a basic Arduino code to read RFID tags using the RC522 module. This code reads the unique identification number from the RFID tag and displays it in the Serial Monitor:

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

#define RST_PIN 9
#define SS_PIN 10

MFRC522 mfrc522(SS_PIN, RST_PIN);

void setup() {
  Serial.begin(9600);
  SPI.begin();
  mfrc522.PCD_Init();
  Serial.println("Place an RFID tag near the reader...");
}

void loop() {
  if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial()) {
    Serial.print("Tag UID: ");
    for (byte i = 0; i < mfrc522.uid.size; i++) {
      Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
      Serial.print(mfrc522.uid.uidByte[i], HEX);
    }
    Serial.println();
    mfrc522.PICC_HaltA();
  }
}

• We include the necessary libraries for SPI communication and the MFRC522 module.
• We define the RST_PIN and SS_PIN, which correspond to pins 9 and 10, respectively, as per our circuit connections.
• In the setup() function, we initialize serial communication, SPI, and the RC522 module.
• In the loop() function, we continuously check if a new RFID card is present using mfrc522.PICC_IsNewCardPresent() and read the card’s serial data using mfrc522.PICC_ReadCardSerial().
• If a new card is present, we retrieve the UID (Unique Identifier) of the card and print it in hexadecimal format to the Serial Monitor. The card is then halted to prevent further reading until another card is presented.

Conclusion

By following this guide, you have successfully set up an Arduino and RC522 RFID module to read RFID tags. You can now use this foundation to create various applications, such as access control systems, inventory tracking, or any project that involves RFID technology. Explore further by integrating the data retrieved from the RFID tags into your projects to enhance automation and security.