Open Source Hardware: What Is It?
by Phillip Torrone
May 04, 2007
Open source hardware is a term we've used here on MAKE and CRAFT for describing some of the projects featured, as well as some of our electronics kits. It was the subject of a talk we participated in at the SXSW conference. But what is it?
There are a few definitions. Some come from "open source software," which is usually considered software "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?
Layers of Open Source 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.
Schematics and Circuit Diagrams
Symbolic diagrams of electronic circuitry. Includes parts lists (sometimes inclusively). Often paired with matching layout diagram. Preferred document type is any sort of image (PDF, BMP, GIF, PNG, etc.).
What parts are used, where to get them, part numbers, etc.
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.
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.
The source code that communicates or is used with the electronics from a computer.
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 is released, documented, or open source.
For example, the WRT54GL wireless router has only the firmware open sourced (GPL).
The Roomba robot vacuum has an "open" API (interface).
Licenses for Open Source Hardware
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:
- Open-source Hardware License, a Creative Commons-like license proposed on Instructables -- Link.
- Open Hardware License, in development by Tuscon Amateur Packet Radio -- Link.
Projects in Open Source Hardware
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:
Chumby "Glanceable" 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 and available as a kit -- Link.
x0xb0x A Roland 303 clone MIDI synth -- Link.
Some of these projects don't provide everything open source, or do it in the most ideal way, and some might use a non-open source tool to modify, but it's a start -- this is all pretty new.
Why Open Source Hardware?
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 reason 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 assemble a kit almost IKEA-style -- but unlike assembling furniture, you can learn new skills and understanding of how things actually work. You might 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.
What else? Fixes, new features, and the "peer production" of the electronics projects/kits usually lead to better kits, communities, and, for some makers, real businesses selling kits -- Link.
All this being said, the pace for hardware is slow and steady. Hardware moves slower than software now: hardware seems to be in the same state that software was in, in the 1980s: lots of commercial developers, very few open source developers. (Or like the 1970s, when only a few had computers at all.) We'd like to see the world of hardware when there are millions of hardware developers.
This is a start. We're interested in your feedback and thoughts, post up in the comments!
Special thanks to Limor Fried, Nathan Torkington, and Eric Wilhelm for their help on this overview.
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