Does anyone have any experience writing code to monitor battery voltage/capacity using a gas gauge? I some mechatronics coding experience, but feel a bit out of range here.

I have a board containing a Linear Technology LTC2942 battery gas gauge. It's being programmed using an Atmega328P and C++.

Does anyone have any good references or example code that could help me get started in the right direction?

 

If you can afford it ($100US) buy the demo board setup and have at it. If you don't want to go that route, all of the info used to build and program the demo board is right here. Understand what they have done and you'll be well on your way.