Step 4: Actually building out some hardware

Goal: Get a lightpainting staff that I can hold

There’s a perfectly good tutorial on the Adafruit site about how they want to build a light painting stick, but I don’t feel like it necessarily represents my needs. I tend to want to wiggle my strips side-to-side and so I tend to want to grab it at different distances up and down the strip.

Also, I’m not at all ready to commit to having one single universal controller, so I’m just keeping the strip and everything else separate for the time being.

The advent of LED strip lighting everywhere means that you can just get a perfectly reasonable aluminum extrusion to hold a LED strip that comes with a built-in diffuser, so I just got one of those.

I spent a bit of time trying to make a good hand-grip in CAD but then it occurred to me that I could just get the low-temperature thermoplastic materials that cosplayers use and just sculpt my handles by hand, the brand name that everybody knows is “Worbla” but there’s actually a zillion brands out there.

So, the materials list for building my staff, which is useful for both my CircuitPython version as well as my ATMega328 version, is something like this:

  • A strip of APA102/SK9822 “DotStar” pixels
  • A metal LED mount extrusion (I used the TAMI LED Strip Channel from SuperBrightLEDs)
  • 4 Pin JST-SM connectors
  • Heat shrink tubing
  • Low temperature thermoplastics (I used Polly Plastics brand)
  • Electronics grade silicone

While I was doing this, I also took a generic 7x9cm PCB and soldered down a set of screw-terminal connectors and a 1000 uF bulk capacitor:


The whole appeal to the thermoplastics is that it’s kind of like a clay-sculpting experience and I’ve already got a heat-gun. And if you smoosh it up against the strip while the plastic is still hot, it’ll just stick like glue. I made the first strip with a single handle at the top that wraps around the back and that worked really well most of the time, but I realized that it really helps to add a second handle at around the mid-point, so my current staff has both, so here’s what my staff looks like:


I’m still fighting a bit with the connectors. I had started out with some random connectors I picked up off of Amazon, but they were clearly flimsy and the first two outings with my strip had me fighting with things.

I decided to get the JST-SM pigtail connectors that SparkFun sells because they are very obviously thicker gauge wire and this time I’ve glued them down with electronics grade silicone to the board and then I put that in heat shrink tubing: