81 IO Expander Modules

The Expander is an easy to use I/O expander module that increases the functionality of the 81 controller board. It plugs into either of the module ports on the 81 controller board. The Expander1 module uses the I2C bus to communicate with the microcontroller on the 81 board. It has DIP switches which enable address selection, as well as to engage or disengage pull-up resistors for the I2C bus. The module interfaces to the outside world via the 10-position pluggable terminal block.