Digital Port Expander Board
Two 8-bit I/O ports with interrupt capabilities.
Port A is available on the ten-pin JST connector (+Vcc and Ground are pins 1 and 9). Port B is available on the top SPIP header, therefore only digital I/O resources are available to peripherals stacked on top of this peripheral. The board operates from either 3.3V or 5V supplies. Three different chip select options are available (selectable by on-board jumpers). NOTE: Two of three SPI Chip Select jumpers must be removed before installation. Remote reset is enabled by default, but may be disabled via the on-board jumper. For more information, refer to the MCP23S17 data sheet.