rppal-mcp23s17 (cargo): MCP23S17 driver  An experimental driver for the MCP23S17 16 bit I/O expander chip addressed over the SPI bus on Raspbery Pi peripherals, such as the  PiFace Digital HAT. Requires RPPAL for the SPI interface. 
Keywords: raspberry|mcp23s17|raspberry_pi|pifacedigital|rppal