While you can program the Trill sensors with C, a popular language is Python, so I have written a very unofficial library that reads the Trill sensors from Python. This is in the MagPi magazine out today, available in newsagents, or on line, or free PDF download.
There is a video of it in action at
Code at:-
https://github.com/Grumpy-Mike/Mikes-Pi-Bakery/tree/master/Trill%20Part%201
Magazine at:-
https://magpi.raspberrypi.org/issues/102
Enjoy.
Next month at this time three projects using Trill sensors.