Here is a list of all files with brief descriptions:

[detail level 1234]

battery
battery.c	Battery monitoring functions for AVR microcontrollers
battery.h	Battery monitoring interface for AVR microcontrollers
common
enums
SPI_enums.h	Enumerations for SPI interface configurations and status
macros
PORT_macros.h	Macro definitions for port operations
STRING_macros.h	Helper macros for stringification in C preprocessor
hal
avr0
adc
adc.c	AVR ADC driver implementation for initialization, configuration, and reading
adc.h	ADC (Analog-to-Digital Converter) configuration and control for AVR microcontrollers
spi
spi.c	Source file with implementation of hardware SPI functions and macros
spi.h	Header file with declarations and macros for hardware SPI
system
system.c	Source file with implementation of system clock initialization
system.h	Header file with declarations and macros for system clock configuration
led
led.c	Implementation of LED control functions using SPI interface
led.h	LED control interface for AVR microcontrollers using SPI
main.c	Main firmware file for RCC RGB LED Color Cube on AVR
main.h	Main header file for RCC firmware