Hardware Reference
In-Depth Information
find existing circuit designs incorporating the same parts, which I could use as a reference
in designing my own board.
Developing successive versions of my devices has also shown me that it's important to
design your circuit boards with iteration in mind. Building extra flexibility into a design
speeds up the process by making it possible to try out different forms and functions
without having to fabricate a new board. For example, breaking out additional microcon-
troller pins, allowing for multiple types of power, and providing different mounting op-
tions can allow the board to be used in new and unexpected ways. Another approach that's
sometimes useful is to provide a footprint on the board for some parts but not actually
solder them on unless they're needed. These development techniques mean that you can
try out new variations on a device's form and function without having to wait for a new
circuit board to be fabricated, assembled, and tested.
Finally, while the design files for a device capture the components selected, they don't
necessarily document the requirements or tradeoffs that led to those decisions, which may
make it more difficult for others to create their own modifications of the device. In the
cellphone, for example, I restricted the circuit to components shorter than 6 mm so that
they'd fit within the laser-cut enclosure. This decision isn't shown in the circuit's design
file but is an important constraint on the components that can be used.
Enclosures
Most of my devices have been housed in cases made on the laser cutter. This has allowed
me to use natural materials, such as wood and fabric, that are rarely seen in commercial
devices. It has, however, required finding clever ways to combine the flat pieces made
by the laser cutter into three-dimensional objects. The radio and speakers use two parallel
laser-cut plywood faces connected by struts. The faces are then wrapped with another ma-
terial (either fabric or veneer). For the cellphone, I've sandwiched the circuit board with
two pieces of plywood and then covered them with veneer. (In general, I'm not a fan of
the finger-jointed boxes found in many laser-cut projects.) All of the designs have fairly
simple contours, making it fast to laser-cut them. That constraint has allowed me to quickly
iterate through designs by actually making them and seeing how well the parts fit togeth-
er and how they relate to the electronics. Because the parts are designed in a simple, open
source 2D drawing software (Inkscape), they are relatively easy for someone else to modi-
fy, whether by simply adding personal text to be engraved or by changing the overall form.
Another approach, which I used for my computer mouse, is to model the circuit board
in 3D (using Rhino or similar software) and then use it as a reference when designing the
enclosure. This strategy takes advantage of the relative flexibility of 3D printing and the
resulting ability to visualize the desired object in software. In addition, 3D-printing parts
