We’d like for — no, we need — the pixels to form a fairly uniform grid, so we can draw legible text.
As previously mentioned, the hat is not a perfect cylinder…it’s tapered. If we simply coil the NeoPixel strip around it, the circumference of each loop is slightly different, and everything will be a jumble rather than a neat grid. Even if you do find a straight-sided hat, the circumference is very unlikely to be a precise multiple of the pixel spacing along the strip.
To address this, we’ll build a sleeve that slips over the hat. This will give us straight sides and an ideal circumference.
Card stock or poster board are reasonable last-ditch substitutes, but something plastic is much preferred. Not expecting anyone to wear this in a downpour…but sometimes one is caught off-guard by a little drizzle or fog, and paper would just go pulpy and fall apart.
This almost worked, but the material seemed just a bit too thick, and all those cable ties added a lot of ugly nubblyness.
If you have the patience to do this with actual hand sewing instead of the cable ties, I wouldn’t rule it out as a possibility! Read on regardless, there’s still the matter of sizing and assembly…
Ideally, the material would be affordable and easily found in a local “big box” store. There were field trips involved.
Two bottles provided sufficient plastic to fit around the hat and sufficient caffeine to complete the project. Diet soda, though vile, rinses out nicely with no sticky residue.
Coke bottles were unsuitable due to their funny shape; had to be something with straight sides.
The two pieces were joined into a longer strip (overlapping about 1 inch) using packing tape on both sides.
The silicone coating on the NeoPixel strip is wonderful for weatherproofing, but does present a challenge: almost nothing on this planet sticks to silicone!
Fortunately there’s one thing that sticks just well enough…carpet tape. Most hardware stores carry this. It’s a double-sided tape that’s wicked sticky and has a removable waxy paper covering.
Cut and apply four strips of carpet tape to the sleeve, running vertically: one each at the front and back, one on either side. Leave the paper backing in place until the next step.