The OpenCAL firmware is a Python application designed to control a Computed Axial Lithography (CAL) 3D printer running on a Raspberry Pi 5. It orchestrates hardware components including a stepper motor (via Pololu Tic T249 or similar), LED array, projector (using mpv), camera (using picamera2), LCD display, and rotary encoder. Users interact via a menu-driven LCD interface to select video files from a USB drive and initiate print jobs, during which the system coordinates motor rotation, LED illumination, video projection, and image capture. The application follows a modular architecture with clear separation of concerns: GUI logic in `gui/`, hardware abstraction in `hardware/`, and configuration management in `utils/`. The LCD GUI implements a state machine for menu navigation, while the hardware layer uses a strategy pattern to support multiple stepper motor drivers (Tic USB, step/dir, UART, and a mock for testing). Configuration is managed through typed dataclasses loaded from a JSON file, allowing easy adaptation to different hardware setups. Key strengths include the reusable stepper motor abstraction layer, which cleanly separates the control interface from driver-specific implementations, and the configuration system that provides a robust, typed interface to hardware parameters. The USB media handler offers a simple, self-contained utility for managing media files on removable storage. The system is actively maintained and targets the Raspberry Pi 5 platform with specific hardware dependencies.