In general, tattoo artists are not electrical engineers. That’s fine; the world needs both professions. But when you need a circuit designed, you’re better off turning to an EE rather than a tattoo artist. And you certainly don’t want an EE doing your new ink. Disaster lies that way.
Surprisingly, [Missa]’s tattoo of a heart-shaped circuit turned out at least to be plausible design, even if it’s not clear what it’s supposed to do. So her friend [Jeremy Elson] took up the challenge to create a circuit that looked like the tattoo while actually doing something useful. He had to work around the results of tattoo artistic license, like sending traces off to the board’s edge and stranding surface-mount components without any traces. The artist had rendered an 8-pin DIP device, albeit somewhat proportionally challenged, so [Jeremy] went with an ATtiny85, threw on a couple of SMD resistors and a cap, and placed two LEDs for the necessary blinkenlights. Most of the SMDs are fed from traces on the back of the board that resurface through vias, and a small coin cell hidden on the back powers it. One LED blinks “Happy Birthday [Missa]” in Morse, while the other blinks prime numbers from 2 to 23 – we’ll assume this means it was [Missa]’s 23rd birthday.
There’s a surprising amount of crossover between the worlds of electronics and tattooing. We’ve featured functional temporary tattoo circuits, prison-expedient tattoo guns, and even a CNC tattoo machine.