A Phillips/NXP PCF8574 8-bit I2C bus digital I/O expander emulator.

Finally!  After a project hiatus, the first example code is uploaded to GitHub.

https://github.com/mdlougheed/I2CIO_PCF8574

This example code will use the I2CIO to emulate an 8-bit I2C digital I/O expander.  Other I/O expanders, such as the TITCA9534. 

The main idea with this code was to show how to set up a basic I2C receiver device.  Other device possibilities are a sensor preprocessor to reduce raw data to a usable form, offloading that task from the controller device.  How about an I2C connected fault tolerant co-processor array. Or maybe an SD card storage system accessible through I2C.   The possibilities are endless.