This project mounts 5 WS2812B LEDs on a cube made out of castellated PCBs. Five of these tiny PCBs are identical, while the one on the bottom is designed to fit a 6-pin header arrangement which allows it to receive and pass along ground and VCC, along with the addressible LED signal. Three LED cubes are used here, wired together and stuck in the top of a wine bottle.

In order to avoid flickering, a diode was used to drop the input voltage, on a variation of the procedure found here. Other than that, wiring is fairly straightforward, with VCC and Ground coming off of the D1 Mini's +5V and GND pins, and data output from GPIO2/D4.

The biggest challenges to this project were avoiding faulty connections in the wiring and in the PCB attachment. It seems that cube PCB arrangements are fun, but difficult to troubleshoot. Also, cutting the glass bottle for Wemos insertion turned out to be more difficult than originally envisioned. Please see the video below for more explanation: