Laser Firmware & Controllers

The board on the machine and the firmware running on it. Diode lasers almost universally run GRBL-derived firmware on cheap 32-bit boards; CO2 cutters split between cheap M2Nano K40 boards, Ruida-class DSP controllers, and FluidNC/grblHAL upgrade boards; galvo systems use proprietary EZCAD/JCZ controllers. See Laser Design & Sender Software for what talks to these boards, and Printer Firmware for the closely related FDM-printer firmware family (GRBL/Marlin overlap).

GRBL family (diode + small CO2)

• ★ GRBL — open source (GPLv3); the original Arduino-era 3-axis G-code firmware. Still the lingua franca for diode lasers; nearly every sender speaks it. v1.1+ adds laser mode ($32=1) with dynamic power scaling.
• ★ grblHAL — open source (GPLv3); modern 32-bit-class fork of GRBL with hardware abstraction layer. Runs on Teensy 4.x, RP2040, STM32, ESP32, iMXRT. Faster motion, better laser timing, optional networking. The contemporary upgrade path for diode + small CO2 builds.
• GRBL-Mega / GRBL-Mega-5X — Mega2560-based forks supporting more axes (rotary, A/B). Older but still used.
• GRBL_ESP32 — Bart Dring's ESP32 port that became FluidNC. Use FluidNC for new builds.

FluidNC (the modern GRBL-class default)

• ★ FluidNC — open source (GPLv3); ESP32-based GRBL successor. YAML-configurable (no recompile per machine), built-in WiFi/web UI, supports laser mode + rotary + multi-axis. Default firmware on Bart Dring's MakerMade boards and many community 6-pack builds. The 2026 sweet spot for "I'm building a custom diode/CO2 frame."
• MKS DLC32 — open-source-firmware-friendly ESP32 board (commonly ships with GRBL_ESP32 or FluidNC) with a 3.5" touchscreen. Cheap K40 / diode-laser brain swap.
• Makerbase MKS TinyBee / MKS Tiny32 — adjacent ESP32 boards.

Smoothieware / re-ARM / re-laser

• Smoothieware — open source (GPL); 32-bit firmware that ran on the original Smoothieboard (LPC1769). Mostly historical now but still alive on Cohesion3D boards.
• ★ Cohesion3D Mini / LaserBoard — closed-hardware, open-firmware (Smoothieware fork); the popular K40 brain transplant before FluidNC took over. Pairs well with LightBurn over GRBL-LPC.
• LightObject DSP / Mini-Gerbil — drop-in K40 controller upgrades; Mini-Gerbil runs GRBL.

Marlin (laser mode)

• Marlin 2.x with laser mode — open source (GPLv3); rare but supported. Mostly seen on combo CNC/laser machines (e.g., Snapmaker, Ortur Aufero variants, FoxAlien). Inferior raster speed vs. GRBL/FluidNC; fine for vector cutting. See Printer Firmware for the broader Marlin context.
• Snapmaker Luban firmware — Marlin-derived; closed-vendor.

Ruida and other CO2 DSP controllers

• ★ Ruida RDC6442G / RDC6445G / RDC6585G — closed source; the dominant DSP family in mid-range CO2 machines (OMTech, Boss, Thunder, many Chinese 80–150W cutters). Speaks proprietary RD/NRD job format; LightBurn DSP and RDWorks both target it natively. Very stable, very capable, very closed.
• Trocen AWC708 / AWC608 — closed source; competitor DSP family; LaserCAD / LightBurn DSP support.
• TopWisdom TL-403CB / TL-410C — older CO2 DSP; LightBurn supports it.
• Leetro MPC6515 / MPC6525 — older Chinese CO2 DSP family; mostly legacy.
• M2Nano / LIHUIYU / Moshiboard — the cheap K40 stock boards. Slow, USB-only, proprietary. Usable via Meerk40t / K40 Whisperer; most users replace them with FluidNC / Cohesion3D / Mini-Gerbil.

Galvo / fiber controllers

• JCZ EZCAD boards (BJJCZ LMC-V4 / LMCV4-FIBER-M) — closed; ship in nearly every Chinese fiber-galvo. Pairs with EZCAD2/EZCAD3 (free) or LightBurn Galvo (paid). See Laser Galvo & Fiber Software.
• SinoGalvo / RDV6445G galvo controllers — Ruida's galvo answer; less common.

OEM / appliance firmware (closed)

• Glowforge firmware — closed source, cloud-tethered; no community access, no offline mode by design.
• xTool firmware — closed source; runs across xTool's diode/CO2/fiber/UV lineup. Updated via XCS. Some xTool D1 / S1 owners flash GRBL/FluidNC for offline use.
• Bambu Lab H2D laser firmware — closed source; new combo printer/laser as of 2025. Stock app required.

Pick this if…

• New custom diode build, modern 32-bit: FluidNC on an MKS DLC32 or 6-pack.
• Existing diode laser, "just works": stock GRBL.
• Cheap K40 brain transplant: Cohesion3D, Mini-Gerbil, or DLC32 + FluidNC.
• Mid-range CO2, you don't want to think about firmware: Ruida (and pair with LightBurn DSP).
• Combo CNC + laser running Marlin: Marlin laser mode (lower the bar for raster speed).
• Fiber galvo: the JCZ board it shipped with — don't fight it.