LuxLibre › Licensing
On this page: Which licence covers what · What you may do · What you must do when you give a light or the files to others · Additional permission for vendor radio libraries · Frequently asked questions · Third-party material · Contributions
LuxLibre is free and open for everyone: hobbyists, schools and companies may use, study, change, build and sell lights based on it. In return, improvements to the shared parts flow back to everyone. This is the same model as ArduPilot, whose code is under the GPL version 3: companies build and sell products with it, and publish the changes they ship.
This page explains the licences in plain words. It is not legal advice; the licence texts in LICENSES/ are what counts. If your business depends on the details, ask a lawyer.
| Part | Where | Licence | SPDX identifier |
|---|---|---|---|
| LuxLibre firmware, tools and scripts | firmware/, tools/, .github/, the Python generators in hardware/*/tools/ and hardware/*/docs/ |
GNU General Public License v3.0 or later, with the additional permission below for the firmware | GPL-3.0-or-later |
| Hardware design files | schematics, PCB layouts, CAD, drawings (including their PDFs) and production files in hardware/ |
CERN Open Hardware Licence v2, Weakly Reciprocal | CERN-OHL-W-2.0 |
| Documentation | docs/, templates/, README files, the build guides and design-chapter PDFs |
Creative Commons Attribution-ShareAlike 4.0 | CC-BY-SA-4.0 |
| FlashKa v0.5 Rust firmware, web app and web tools | hardware/flashka-keychain-v05/firmware/, app/, tools/web/ |
MIT or Apache 2.0, at your choice | MIT OR Apache-2.0 |
| FlashKa Rust firmware (0.6.0 for v0.6 and 0.7.0 for v0.7, one code base), web app and web tools | hardware/flashka-keychain-v06/firmware/, app/, tools/web/ |
MIT or Apache 2.0, at your choice | MIT OR Apache-2.0 |
| FlashKa v0.7 design files, scripts and documents | hardware/flashka-keychain-v07/ (it has no firmware or web pages of its own: its firmware 0.7.0 and the web pages come from the v0.6 folder, row above) |
as for v0.6: design and production files CERN-OHL-W-2.0, the Python generators (tools/, docs/build_pdf.py) GPL-3.0-or-later, the documents and their PDFs CC-BY-SA-4.0 |
CERN-OHL-W-2.0, GPL-3.0-or-later, CC-BY-SA-4.0 |
| EDCO v0.1 design files, scripts and documents | hardware/edco-v01/ (its firmware is the LuxLibre firmware, board firmware/boards/edco-v01/) |
design files (CAD, STEP) CERN-OHL-W-2.0, the Python generators (tools/) GPL-3.0-or-later, the documents and pictures CC-BY-SA-4.0 |
CERN-OHL-W-2.0, GPL-3.0-or-later, CC-BY-SA-4.0 |
| Project web site (GitHub Pages) | site/ |
MIT or Apache 2.0, at your choice | MIT OR Apache-2.0 |
| Generated AVR register header | firmware/ports/attiny1616/tiny1x_io.h |
Apache License 2.0 (Microchip’s device description) | Apache-2.0 |
Source files name their licence in their first lines (SPDX-License-Identifier: ...); that line
wins over this table. Design and data files that cannot carry such a line (KiCad, STEP, STL,
DXF, Gerbers, CSV, spreadsheets, images, PDFs) take the licence of their row in this table. The
root LICENSE file holds the GPL text because the firmware is the largest part; all
licence texts are in LICENSES/.
With every part of LuxLibre you may, for any purpose including commercial ones:
Nothing is required for private use or for lights you keep. The duties start when you distribute: sell or give away lights, firmware images or design files.
Permissive: keep the copyright and licence notice; no duty to share changes. The firmware links
Espressif’s binary-only radio libraries for Bluetooth, which these licences allow. The built
installer pages (app/aurora-flasher.html of v0.5, app/flashka-flasher.html of v0.6) also
contain esptool-js (Apache-2.0, Espressif Systems) and pako (MIT and Zlib). Both pages keep the
libraries’ licence comments; the v0.6 page also names both in its header comment and its footer.
The licences cover the files, not the names. How to use “LuxLibre” and “FlashKa” for your own products is explained in TRADEMARKS.md.
Wireless microcontrollers need binary-only libraries from the chip maker for their radio and PHY (for example Espressif’s Bluetooth and Wi-Fi libraries for the ESP32 family). Without an exception, the GPL would not allow distributing firmware that links them. Therefore:
As an additional permission under section 7 of the GNU General Public License version 3, the copyright holders of the LuxLibre firmware give you permission to combine the firmware with the binary-only libraries that a microcontroller maker distributes in its software development kit for the radio, PHY and low-level hardware support of its chips, and to convey the resulting firmware, without providing source code for those libraries. All other parts of the firmware stay under the GPL. If you modify the firmware, you may extend this permission to your version, or remove it.
The current LuxLibre firmware does not use such libraries yet; the permission is there so that a Bluetooth version can be distributed.
Can my company sell flashlights that run LuxLibre? Yes. Publish the firmware source you ship (with your changes and board header), let users install their own builds, and follow the name rules in TRADEMARKS.md.
Do I have to publish my own PCB if I only use the LuxLibre firmware?
No. The firmware licence covers the firmware. A board you designed yourself, without starting
from LuxLibre hardware files, is yours. Only the board header (the pins and limits in
firmware/boards/<board>/board.h) is part of the firmware source and is shared with it.
I started from the FlashKa PCB and changed it. What now? Your changed design files are a modified version of a CERN-OHL-W-2.0 design: when you sell lights made from them, publish the changed design files under the same licence and tell buyers where to find them.
Can I write a closed-source phone app that talks to a LuxLibre light? In general, a separate program that talks to the firmware over its console or a wireless protocol is not a modified version of the firmware, so the GPL does not cover it. Code you copy from LuxLibre into the app is a different case.
Can I put LuxLibre firmware into a product that uses a closed-source library? Only if the complete source of that library can be provided under terms compatible with the GPL version 3, if it is a “System Library” in the sense of GPL-3.0 section 1, or if it is a chip maker’s radio or PHY library covered by the additional permission above. Otherwise keep the closed part outside the firmware (for example on a separate chip).
Why “or later” for the GPL? It lets the project move to a future GPL version if one is needed, without asking every past contributor.
What about safety and warranty? All these licences come without warranty. Whoever builds and sells a light is responsible for it meeting the laws of the market it is sold in; SAFETY.md and docs/design-rules.md help, but they do not replace testing and certification.
firmware/ports/attiny1616/tiny1x_io.h is generated from Microchip’s ATDF device description
of the ATtiny1617 (Copyright (c) 2018 Microchip Technology Inc., Apache License 2.0), as
distributed in the vendor folder of the avr-device crate. The generator script
atdf_to_header.py is GPL-3.0-or-later.firmware/ports/ch32v003/ch32v003_regs.h takes register addresses and bit positions from the
ch32-metapac crate (MIT OR Apache-2.0), generated from WCH’s SVD files, and from the CH32V003
reference manual.hardware/flashka-keychain-v05/app/aurora-flasher.html and
hardware/flashka-keychain-v06/app/flashka-flasher.html bundle esptool-js 0.7.0 (Apache-2.0)
and pako (MIT and Zlib).Contributions are accepted under the licence of the files they change (“inbound = outbound”, including the additional permission for the firmware), with a Developer Certificate of Origin sign-off on every commit. Details: CONTRIBUTING.md.