Browse the full file list, or here is some of the most useful documentation:

mcp_funcs.h - Functions to interface with MCP23017 GPIO expander and MCP4728 DAC
mcp_regs.h - Initialization and command macros and constraints for MCP23017 GPIO expander and MCP4728 DAC
led_driver.h - Functions to control LED and knob ring displays
cv.h - Control voltage generation engine header
console_state_bucket.h - Header file for console parameter data saving and reporting code (for the bucket controller)
main.c - Main C file
main.h - Main header