Light up jewelry is nothing new – we see wearables all the time here. But home brew, self-contained, programmable LED earrings that are barely larger than the watch batteries which power them? That’s something worth looking into.
Settle back and watch [mitxela]’s miniature wizardry in the video below, but be forewarned: it runs 36 minutes. Most of the video is necessarily shot through a microscope where giant fingers come perilously close to soldering iron and razor blade.
The heart of the project is an ATtiny9, a six-legged flea of a chip. The flexible PCB is fabricated from Pyralux, which is essentially copper-clad Kapton tape. [Mitxela] etched the board after removing spray-paint resist with a laser engraver – an interesting process in its own right.
After some ridiculously tedious soldering, the whole circuit wraps around a CR927 battery and goes into a custom aluminum and polypropylene case, which required some delicate turning. Hung from off-the-shelf ear hooks, the 12 multiplexed LEDs flash fetchingly and are sure to attract attention, especially of those who know Morse.
This isn’t exactly [mitxela]’s first tiny rodeo, of course. We’ve featured his work many times, including a Morse code USB keyboard, the world’s smallest MIDI synthesizer, and the world’s smallest MIDI synthesizer again.