Open Source Hardware is hardware that keeps its designs available in a way similar to the open source in software.

Open Source Hardware is used as an alternative to the related and perhaps broader term of Open Hardware. It is in the process of being replaced more and more by the successor movement, i.e. Open Design.

Typology

Developed by Make magazine at http://www.makezine.com/blog/archive/2007/04/open_source_hardware_what.html

The original article has many examples with diagrams.

Electronic hardware can be divided up into layers, each of which has different document types and licensing concerns. Each level can be open sourced, but the exact nature of what it means to open it varies. In practice, not every layer is fully open. Often only a subset of the layers are released, documented or open source.

1/ Hardware (Mechanical) diagrams

Dimensions for enclosures, mechanical subsystems, etc. For 2d models, preferred document type is vector graphics file, with dimension prints, DXF or AI, etc.

2/ Schematics & Circuit diagrams

Symbolic diagrams of electronic circuitry, includes parts list (sometimes inclusively). Often paired with matching layout diagram. Preferred document type is any sort of image (PDF, BMP, GIF, PNG, etc)

3/ Parts list

What parts are used, where to get them, part numbers, etc.

4/ Layout diagrams

Diagrams of the physical layout of electronic circuitry including the placement of parts, the PCB copper prints and a drill file. This is often paired with a schematic. Preferred distribution is Gerber RS274x and Excellon (for drills). These are like PostScript for printers but the primitives aren't text and arcs, they're lines of solder and components.

5/ Core/Firmware

The source code for that runs on a microcontroller/microprocessor chip. In some cases, the code may be the design of the chip hardware itself (in VHDL). Preferred distribution: text file with source code in it, as well as compiled 'binary' for the chip.

6/ Software/API

The source code that communicates or is used with the electronics from a computer.

Example

"OpenSparc is Sun's attempt to bring open-source thinking and cooperation into the realm of hardware design:

Goals of the OpenSPARC Initiative

To significantly increase participation in processor architecture development and application design by making cutting-edge hardware IP freely available.