Jellyfish Costume

Once again, Halloween provides the inspiration. This time the goal was a jellyfish — no code, no microcontrollers, just a little design and a little math. (A nice change of pace from my usual projects, where the wiring is half the battle.)

The key ingredient was an off-the-shelf LED “curtain” — one of those grids of hanging light strands that simply wouldn’t have existed back in the days of yore. Drape it over a clear dome umbrella and you’ve basically got a jellyfish. The math was just working out how the strands would fall and how to spread them so the whole thing reads as a jellyfish and not a tangle of Christmas lights.

The hard part wasn’t the look — it was the logistics. How do you hold an umbrella over your head all night when both hands are busy opening a pillowcase and filling it with candy? You can’t. So the umbrella had to support itself.

The solution: a marching band drummer’s harness. It’s already built to carry weight off your shoulders and hold something rigid out in front of you, so it was most of the way there right out of the box. A little modification — some zip-ties, a couple of new screw points — plus a bit of fit-up, and we were in business. The umbrella rides up off the back like a bell, hands free.

A fun little mini-project with highly visible results — and you can spot it coming from half a block away.