There are a few definitions, some of which come from “open source software,” which is usually considered software’s “source code under a license (or arrangement such as the public domain) that permits users to study, change, and improve the software, and to redistribute it in modified or unmodified form.” So how does this translate to hardware? Electronic hardware can be divided up into layers, each of which has different document types and licensing concerns.
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.
Example: Motor-driven screw block from the RepRap ‘s thermoplast extruder head, an open source 3D printer.
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).
Example: 3.3V and 5V regulator schematic from Chumby, the open source information device.
Parts List
What parts are used, where to get them, part numbers, etc.
Example: Parts List from the open source Roland 303 MIDI synth clone, the x0xb0x.
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.
Example: Board (.brd) files for the MAKE: Daisy Open Source MP3 Player.
Core/Firmware
The source code 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.
Example: Open core 8080 compatible CPU code snippet from executing the 8080 instruction set.
Software/API
The source code that communicates or is used with the electronics from a computer.
Example: A screenshot of the Arduino IDE showing a simple example program.
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.
For example, the WRT54GL wireless router only has the firmware open sourced (GPL).
The Roomba robot vacuum has an “open” API (interface).
The Ambient Orb (information device) is not open source, but the schematics and parts list are documented and available for people to tinker with and possibly build their own.
There are ongoing efforts from a variety of groups and people who are trying to figure out how an open licensing of hardware might work too:
Projects
Projects are the the fun part: what are people actually doing? Here are a few examples (some previously noted) of projects that are close to “pure” open source hardware projects:
Arduino physical computing platform (just shipped 10,000!) – Link.
Chumby ‘glancable’ information device – Link.
MAKE: Daisy MP3 Player – An open source MP3 player – Link.
RepRap / Fab@Home – Open source 3D printer – Link.
Open Cores – A collection of VHDL cores for FPGA chips (“often cited as the first example of true OS hardware”) – Link.
OpenEEG – An EEG design that is OS & available as a kit – Link.
x0xb0x – Roland 303 clone MIDI synth – Link.
Some of these projects don’t provide everything in the most ideal way, or might use a non-open-source tool to modify, but it’s a start — this is all pretty new.
At MAKE & CRAFT, we’re trying to foster this nascent hardware movement by encouraging our kit makers to consider open source hardware and a license that makes sense when developing kits with us. So far it’s worked out, and we’re looking forward to providing not only more open source hardware kits, but electronics that are more “open” than what’s out there now.
Why is this a good thing? The most obvious one for MAKE & CRAFT is the educational benefits: an open source hardware project or kit allows makers to build something completely from scratch (etching boards, etc) or assembling a kit almost IKEA-style, but unlike assembling furniture, new skills and understanding of how things actually work can be learned. One could say the building of the electronics is the “compiling” portion of the project, similar to software. Events like dorkbot and our Maker Faire are places for participation, and online, Instructables.com is a great place to look.
What else? Fixes — new features and the “peer production” of the electronics projects/kits usually lend themselves to better kits, communities, and for some makers making real businesses selling kits – Link.
All this being said, the pace is slow and steady; hardware moves slower than software now: fabbing, which may decrease but is unlikely to fully go away. And hardware seems to be in the same state software was in the 1980s; lots of commercial developers, very few open source developers (or like 1970s when only a few had computers at all). We’d like to see the world of hardware when there are millions of developers.
torrone, phillip. What is open source hardware? A start:Open source hardware projects and examples [Internet]. Version 3. Knol. 2008 Jul 23. Available from: http://knol.google.com/k/
