Open hardware¶

libdrone is released under CERN OHL-S v2. Not MIT, not Creative Commons, not "free to use for non-commercial purposes." CERN OHL-S — the strongest copyleft licence available for hardware. If you build on it, what you build is open too.

This was a deliberate decision, and it is worth explaining why.

Why CERN OHL-S¶

Open hardware is harder to licence than open software. Code is unambiguous — the source is the thing. Hardware has a source (the design files) and a manufactured form (the physical object), and the relationship between them is not always clean.

CERN OHL-S v2 was designed by CERN specifically for hardware. It requires that derivative works be released under the same terms. It defines "source" clearly for hardware contexts — the design files, the documentation, the manufacturing files. It has been legally reviewed. It is the right tool.

The reason to choose the strong copyleft version over permissive alternatives comes down to one question: what happens if a company takes the design, improves it, and closes the improvements?

With a permissive licence, they can. With CERN OHL-S, they cannot. Improvements to libdrone-derived hardware must be contributed back. The community gets the benefit of every improvement. Nobody can privatise the commons.

What open hardware actually means¶

It means the design files are public. The full FreeCAD/CadQuery for every libdrone printed part is in the repository. Every measurement is in the variables file. Every component choice is in the hardware document with the reasoning explained.

A person who has never met me can build this. They do not need to ask me for files. They do not need to sign an NDA. They do not need to wait for a vendor to restock. They need a printer, €250 in components, and the documentation.

That is what open means. Not "free to view." Reproducible.

The payload interface standard¶

The GX12-7 dual connector standard — the payload interface at the heart of libdrone — is documented as an independent specification. Anyone can build a payload to this interface without modifying the drone. The interface is stable. The drone is the carrier. The payloads are the point.

This is the architecture decision that makes libdrone a platform rather than a project. One drone, any sensor. The interface is the product.

Full documentation at libdrone.eu.