Adding Channels for Air Data Vanes to Firmware

I’ve got a Pixhawk Autopilot system and I’m trying to get it to receive voltage data from a pair of potentiometers. I have little experience with the firmware, and I don’t know where to begin on modding it, but my understanding is that I need to add a data channel for each potentiometer. Any advice would be greatly appreciated. If you need more information, please let me know.