Hardware Reference
In-Depth Information
(Source: Screenshot is from
www.sparkfun.com/products/11114
)
Figure 14.3
SparkFun product page as an example.
Hardware Source Files
Open hardware source files are commonly referred to as design files and contain the source
materials to build your product. For electronics, open hardware source files are commonly
schematics and board files. The Open Source Hardware Definition states this about docu-
mentation:
The hardware must be released with documentation including design files, and
must allow modification and distribution of the design files. Where documentation
is not furnished with the physical product, there must be a well-publicized means
of obtaining this documentation for no more than a reasonable reproduction cost,
preferably downloading via the Internet without charge. The documentation must
include design files in the preferred format for making changes, for example the
native file format of a CAD program. Deliberately obfuscated design files are not
allowed. Intermediate forms analogous to compiled computer code—such as
printer-ready copper artwork from a CAD program—are not allowed as substitu-
tes. The license may require that the design files are provided in fully-documented,
open format(s).
From this piece of the definition, we know that to consider our project open source, we
must release design files allowing modification and distribution of the design files (or
hardware source files). This means design files cannot be copyrighted, and must be re-
leased under an open source license and preferably released on the Internet because the
cost of reproducing and sharing those files when done so electronically is free. It is also
worth considering which file types are most commonly used. If you use an unusual or ob-
solete format, that choice can affect the user's experience. Consider also using version
control and commonly accepted units of measurement.
For example, an error often made in design files that depend on measurements is to not
specify the unit of measure used in the design. For example, many designers use milli-
meters, but others use inches or centimeters. Including a “key” for measurements and oth-
er important information somewhere within the file listing can help users exchange in-
formation, thereby ensuring more continuity between users. All too often, and especially
with .svg files, a user will move a file between systems, only to find that one system's de-
fault is in inches while the other system defaults to centimeters. What this can mean when
fabricating is that you might end up with the same piece in two different sizes: one printed
10 centimeters in length and another printed 10 inches in length!
