81P-0100; Expander1 Module for the Graves Electronics Controller Board
81P-0001; based around the
NXP PCF8574A chip; plugs into either of the module ports on the controller board; uses I²C bus to communicate with the microcontroller; DIP switches to enable address selection or to engage or disengage pull-up resistors for the I²C bus; interfaces to outside world via 10-position pluggable terminal block; 2.00" x 2.44", max. component height 0.36" top of board
