XBee ZigBee RF Modules, Digi International. XBee ZigBee RF modules provide wireless connectivity, a simple way to integrate mesh technology into applications. The Serial Peripheral Interface (SPI) provides a high-speed interface and optimises integration with embedded microcontrollers. XBee RF modules require no configuration or additional development. Supports binding and multicasting, for easy integration into home automation applications 15 Input/Output digital lines Receiver sensitivity of 110 dB Sleep current of sub 1 μA UART, SPI or over the air firmware upgrades