RepRapFirmware

RepRapFirmware (RRF) is an open-source firmware for 3D printers, developed for RepRap-inspired machines. It is designed primarily for 32‑bit controller boards used in the RepRap ecosystem, and is especially associated with the Duet family of control boards. RRF aims to provide robust hardware control and a convenient configuration workflow through human-readable files and a web interface.

Key features include support for multiple extruders and tool changes, precise temperature and heater control through PID loops, fan and heater management, and sophisticated bed handling. It includes flexible bed leveling options such as mesh bed compensation, along with standard endstop handling and homing sequences. The firmware supports various networking and storage options and exposes a browser-based interface called Duet Web Control for monitoring, file management, and configuration editing.

Configuration is file-based rather than recompiling. The machine geometry and settings live in config.g, including axis travel limits, steps per millimeter, max speeds, and homing directions. Additional behavior is implemented with macro files and G-code commands. RRF runs on printers with one or more extruders and heated beds, and can accommodate tool changes and advanced standby/ power-management workflows.

Developed by the RepRap community in conjunction with Duet3D, RRF is maintained as open-source software and has seen widespread use on Duet controllers and other compatible boards. It is regarded as a mature alternative to firmware like Marlin for users seeking a browser-based workflow and configuration-driven setup.