Thus begins the Choose Your Own Adventure part of the project. There is no One Right Way to do this. Your access to and experience with different materials and tools might be entirely different than what’s shown here, so consider these merely guidelines, not a blueprint.
This 3/4" pine molding is the perfect width for the NeoPixel strip. It typically comes in 8 foot lengths, which can be cut as needed.
Unfortunately, the dowels in the “hobby wood” section of most hardware stores are typically 36 inches long…just a bit too short to support a full meter of NeoPixel strip. So you’ll probably need to buy a full 8' length of molding. Many stores will provide one or two cuts for free.
PVC pipe might seem an alluring option, but it’s not recommended. It lacks rigidity, and the round cross-section is difficult to attach the NeoPixel strip to.
How big will your paintbrush be? In what ways do you envision moving it around?
A “T” configuration puts the grip at the center, providing different options (such as spinning).
Or you could mix and match. A “T” with a longer bar for multiple grip options.
The bar should be a minimum of 42 inches long…that’s just a little longer than the 1 meter strip with the end caps.
Mark and drill some small pilot holes, and screw the frame together…
There are a few LEDs on the Arduino board and shield that could produce undesirable light streaks in your paintings, so consider some kind of enclosure.
We used an Altoids-sized mint tin for ours…it’s almost exactly the same size as the Arduino and shield.
If you prefer plastic, there's a nice weatherproof box in the shop that is easier to work with - you can drill and cut it with basic hand-tools.
As an alternative, you might track down a plastic box that’s big enough for the Arduino and shield. Even a small paper box (like playing cards come in) may suffice. Look around you!
Here the footprint of the tin is traced onto index cards and cut out to produce a liner. Later this will be glued or taped in place.
Vinyl contact paper is another option, if you have some in your craft stash.
Notice with this tin that the SD slot needs cutouts both in the base and the hinged lid.
Also, mark two spots on the bottom where screw holes can be drilled. These will hold the enclosure to the frame.
Watch out for sharp edges, and wear eye protection when using tools!
After cutting, metal edges can be smoothed with sandpaper or an emery board (nail file).
Wash out the case thoroughly after doing this, and allow it time to dry. Any lingering metal shavings or dust will wreak havoc with the electronics!
The tin shown here was painted matte black to reduce reflected light from the environment. Not a crucial step, but go ahead if you already have some paint on hand.