Product DescriptionFeature:Small dimension and easy to embed into your projectSupport I2C, SPI and HSU (High Speed UART), easy to change between those modesSupport RFID reading and writing, P2P communication with peers, NFC with Android phoneUp to 5cm~7cm reading distanceOn-board level shifter, Standard 5V TTL for I2C and UART, 3.3V TTL SPIArduino ...