Is there a library to use I2C bus on RPi for Mono/.NET?
I was trying to find anything, but there are only libraries to work with GPIO but not with I2C.
After long fruitless searching, I still didn't find anything on C#/Mono. So, I had to create my own library. In case someone else is looking for a similar solution, I put it on GitHub: https://github.com/mshmelev/RPi.I2C.Net
I don't know about .Net libraries but have you looked into overo-blinkm?
It was written for controlling an RGB LED. I am sure you can tweak it meet your requirements. It is written for the Gumstix board. I was able to cross compile it for the Raspberry Pi using the native makefile available in the library. I just had to change the I2C address to i2c-dev0
I use this one. I did a lot of testing, works well. MIT license. https://github.com/thomas3d/RPiCSIO
I have tested several other before, which had some problems.