This is Module works as an adaptor to connect an Rfid reader (MFRC522) with a Arduino micro-controller. It communicates with the Arduino using only a Input Pin. You can operate this Module as a stand alone access controller using the Relay NO/COM contact. Connection with the Module can be done either with a UTP cable or with 4 cables using the screw terminal block. On the Module there led indicators and a buzzer. Also the 2 dip switches controls the add master card mode and the delay – no delay feature.

Using this Module you are able to connect up to 20 Rfids to a Arduino Uno.

You are able to register up to 150 users cards using the Master Card.

EXPANDED TECHNICAL DETAILS

RFID Protocol Standardization

This project creates a universal bridge for interfacing 13.56MHz RFID modules (like the RC522) with various systems.

• Spi-to-Serial Adaptor: The Arduino acts as an intermediate controller that handles the complex SPI initialization and handshake of the RC522. It then outputs the unique UID (Unique Identifier) of a scanned tag via simple Serial (RX/TX) commands.
• EPROM Tag Storage: Includes a feature to "Whitelist" specific tags. The authorized UIDs are stored in the Arduino's non-volatile EEPROM, allowing the device to act as a standalone security gate without needing a constant PC connection.

Deployment Flexibility

• Indicator API: Provides digital "OK/Fail" output pins that can be directly connected to door strikers, sirens, or higher-level industrial PLCs for secure access control implementation.