RC522 RFID 13.56 MHz READER/WRITER MODULE 

The RC522 RFID 13.56 MHz Reader/Writer Module is a versatile contactless RFID device designed to read and write data to 13.56 MHz RFID cards, tags, and key fobs. It uses the NXP MFRC522 IC and supports ISO/IEC 14443A standard cards, including MIFARE Classic 1K/4K, Ultralight, and NFC Type A cards, making it ideal for access control, attendance systems, cashless payment prototypes, and educational electronics projects.

The module operates by generating a 13.56 MHz electromagnetic field through its onboard PCB antenna. When a compatible RFID card or tag enters this field, it is energized via electromagnetic induction and exchanges data with the reader. The RC522 can read and write information stored in the tag’s memory. Communication with microcontrollers is typically via SPI (default), but some implementations also support I2C or UART interfaces, allowing easy integration with Arduino, ESP32, ESP8266, Raspberry Pi, and PLC systems.

Operating at 3.3 V DC, the module can detect RFID tags at a distance of 5–7 cm depending on the tag type and antenna configuration. Its compact design, onboard antenna, and easy-to-use interface make it suitable for rapid prototyping and embedded system applications.

Applications include RFID-based access control, employee attendance and identification systems, smart locks and security devices, cashless payment and ticketing systems, inventory tracking, and educational electronics or IoT projects. The RC522 module is popular for both hobbyist and professional applications due to its reliability, versatility, and ease of integration.