HexBlink
Some months ago I came across a circuit simply consisting of a bunch of 1.5 hz blinking LEDs all wired in parallel.
With the individual LEDs being individually clocked but partially synchronized, the pattern it creates is quite mesmerizing.
I then ordered some LEDs and filled out a protoboard to test it out myself. The result is entirely meaningless, but very fancy.
Then I began designing an actual circuit for etching. I of course went with a hexagonal design, because bestagons and so on. The circuit features 91 LEDs, each with its own 1206 SMD resistor, and pins for power and strain relief. Along the edge of each board, the power rails are exposed, allowing the boards to be soldered side by side.
Along with two other projects I ordered a few PCBs, and when they arrived, it was immediately quite clear that there was a better alternative to just red blinking LEDs. So I ordered a bunch of candle flicker LEDs as found in electronic candles. The result is a pretty funky beehive:
The circuit is available on github. It should be noted that assembly takes at least a few hours per board.