The RFID Module adopts MFRC522 IC as the mian Chip ,which is a highly-integrated reader/writer IC for contactless communication at 13.56MHz. The MFRC522 reader supports ISO/IEC 14443 A/MIFARE Mode. The MFRC522 supports following interfaces: 1、Serial Peripheral Interface 2、Serial UART 3、I2C_bus Interface This Module uses SPI as the interface to the external board. Features: Highly integrated analog circuitry to demodulate and decode responses Buffered output drivers for connecting an antenna with the minimum number of external components Supports ISO/IEC 14443 A/MIFARE Typical operating distance in Read/Write mode up to 50 mm depending on the antenna size and tuning Supports MF1xxS20, MF1xxS70 and MF1xxS50 encryption in Read/Write mode Supports ISO/IEC 14443 A higher transfer speed communication up to 848 kBd Supports MFIN/MFOUT Additional internal power supply to the smart card IC connected via MFIN/MFOUT Supported host interfaces SPI up to 10 Mbit/s I2C-bus interface up to 400 kBd in Fast mode, up to 3400 kBd in High-speed mode RS232 Serial UART up to 1228.8 kBd, with voltage levels dependant on pin voltage supply FIFO buffer handles 64 byte send and receive Flexible interrupt modes Hard reset with low power function Power-down by software mode Programmable timer Internal oscillator for connection to 27.12 MHz quartz crystal 2.5 V to 3.3 V power supply CRC coprocessor Programmable I/O pins Internal self-test