Sorry, I hoped to finalize the new I2c class over the weekend. Didn't happen. If you update your board with the instructions above, you will have a mostly working I2c class.
There is C++ example of I2c communication for the MPR121 sensor in
This does not use the new
I2cRt class, but maintains its own I/O loop in a separate thread/
There is also an example Pd patch, if writing user-space I2c drivers from PureData is your thing! The
core/default_libpd_render.cpp is the backend for this Pd-I2c, and exemplifies the use of the
I2cRt class in
include/I2cRt.h which uses
readRt to write/read to the I2c bus asynchronously from the audio thread.