Three things combined to promote this project. Several years ago my generous wife bought me an expensive “Mindstorms” LEGO set which is intended for exploring programming of robots. I felt guilty about not using it after an initial robot construction, since disassembled. This Christmas she bought me a Christmas tree kit with 24 “neopixel” LEDs. Since I soldered 3 incorrectly, I was left with 4, including a spare.
Also many years ago I had bought 10 8mm 4-lead LEDs which I could not use as I had no information.
I rediscovered them when I sorted out my stock of LEDs and now realized that they were also neopixels. I now knew how to use these because of the “Octagon” project.
I opened up the Mindstorms box and saw it lacked bricks to make structures, so I bought about a kg of these on Craigslist for $20. This is made with these. A lattice inside which holds the 3 circuit boards with the LEDs is made with Mindstorms parts.
The right side uses the 4 5mm LEDs, while the front and left side use the 8mm LEDs. Each board has a 6-pin header at the bottom. They are interconnected by a single custom harness made with ”raw” jumpers and housings from Pololu. The bottom left LED on the right side is extended to the processor board with 3 wires.
The processor board rests on ledges at the sides.The processor is on the top side for programming access. Also on the top is the doppler radar board. The wiring and the LED and power connectors are hidden underneath.