For this section, refer back to the schematic (Figure
2), Parts List, major components (Figure 4), and LED
The schematic is divided into
two sections to correspond to the
two boards made to fit the
enclosure I selected for a
prototype (see photos). The
larger section is the logic board
and the smaller is the LED board.
In my prototype, the selected
enclosure is a clear heavy plastic
box designed to hold 150
baseball cards. Found on eBay for
about $2, it fits the parts neatly
when the eight AA batteries are
used for the power supply. Plus,
being transparent, it offers the
builder a view of the inner guts
while making things fit together.
The two boards and the
batteries are (optionally)
interconnected with three-pin
Molex connectors that I found at
MPJA.com. While the selected
enclosure was handy during
development, the builder should
consider other enclosures —
especially attractive are
cannibalizing a large flashlight’s
enclosure — either a pistol-grip or
If you choose to use a
smaller battery or an external wall wart, the reduced
volume would allow something smaller, like a cylindrical
flashlight. The choice is yours.
The prototype in the photos used a printed
wiring board (PWB) for the logic board, and a
back-to-back pair of perf boards for the LED board.
Again, you can choose this configuration or any
other you’re comfortable with. The layout for the
30 October 2017
■ FIGURE 4. Component parts of the StroboDuino as
assembled in a card file box.
■ FIGURE 5. The LED board. This shows the
■ FIGURE 3A. The
Arduino "stops" the
boxer fan at 3,090
■ FIGURE 3B. At the
second harmonic ( 6,180
FPM), the fan again
appears to stop, but the
doubling of the color
dots gives away that it's
the second harmonic.
■ FIGURE 3C. The third
harmonic and the color
dots overlay each other,
adding to gray.