ITEAD PN532 NFC module as its name implies is based on PN532 chip and used for 13.56MHz near field communication. The module is equipped with onboard antenna thus no external antenna coil is needed. It is compatible with SPI IIC and UART interface for communication. With NFC library support for Arduino and Raspberry Pi offered by us it is quite convenient for development of products with NFC functions. Features Longest effective communication distance of 3 cm. Supports switching of SPI IIC and UART interface. Can be used for 13.56M non-contact communication. Compatible with ISO14443 Type A and Type B standards. Specification IC NXP PN532 Operating Voltage 3.3V Power Supply Voltage 3.3~5.5V Max Supply Current 150mA Working Current(Standby Mode) 100mA Working Current(Write Mode) 120mA Working Current(Read Mode) 120mA Indicator PWR Interface SPI Interface Std Raspberry Pi 20pins Interface Hardware. There are two slide switches on the board for selection of interface mode: SET0 SET1 UART L L SPI L H IIC H L