RFID
RC522 RFID Module
The RC522 is a 13.56MHz RFID module that is based on the MFRC522 controller from NXP semiconductors. The module can supports I2C, SPI and UART and normally is shipped with a RFID card and key fob.
PN532- NFC RFID Module
We recently hear a lot about NFC. This feature is available in the latest high end smart phones present in the market. NFC stands for Near Field Communication.
EM18 - RFID Reader Module
EM18 RFID Reader is a module which reads the ID information stored in RFID TAGS. This ID information is unique for every TAG which cannot be copied.