Hardware Reference
In-Depth Information
If you're designing a stand-alone board, you can design your board outline in any soft-
ware that enables you to export a DXF file; this includes most three-dimensional model-
ing tools (e.g., OpenSCAD, SolidWorks, Rhino) as well as two-dimensional vector graph-
ics software (e.g., Inkscape, Illustrator). If you're designing a housed board, you can em-
ploy the same software tools, but it is often most beneficial to use three-dimensional mod-
eling software for visualizing physical constraints. Whatever software you use, defining
your model parametrically will allow you to make any adjustments down the line much
more easily.
As the board size is determined by the physical components on the board, it makes
sense to start by modeling any mechanical constraints for your space-limiting compon-
ents. For example, with Replay, the precise placement of the audio connector and jack was
modeled first.
Figure 7.4
shows the two boards necessary for each piece of the Replay kit:
the Arduino derivative and the hall-effect board (a board containing hall-effect sensors
used for determining the orientation of each piece relative to its neighbor).
(Source: Images CC-BY-SA Tiffany Tseng)
Figure 7.4
Board outlines in the Replay construction kit.
Once the fundamental components are placed in your model, you can design the
widest-possible footprint for your custom Arduino derivative. In designing a housed
board, it's often helpful to include alignment features such as bosses, or screw posts to
screw your board into the housing, or keyed-features (as shown with the slot in the
hall-effect board in
Figure 7.4
). Additionally, you should leave clearance for a program-
ming cable and connector if it's necessary to easily reprogram your boards.
