Redditor littlespleen made their own RP2040-powered wristwatch. It’s not the same as the TFT screen versions we’ve seen previously — this one features tons of meticulously soldered LEDs to show the time in a way similar to the hands on analogue timepieces. It’s colourful, it’s geeky, we love it.

Sixty individually addressed LEDs are packed onto the face of the tiny timepiece, and each is capable of showing different parts of the time. Hours are represented by a blue LED, minutes are in green, and seconds are in red.

Ever so fiddly

The maker designed the body of the watch in KiCad. We love small stuff, and teeny PCBs are always appealing. It measures just 28.5mm across, a perfect size for a comfortably wearable piece of tech.

All of those LEDs took as long as you can imagine to place. Each was set with tweezers and secured with a heat pad. Hard pass from me, seeing as I don’t have the patience for this kind of intricate soldering. Kudos to littlespleen.

Comfort upgrades

Future upgrade plans include encasing the build inside an indestructible steel case with space for “the largest battery” the maker can make fit. That many LEDs pull quite a bit of power, and if we want this to be a piece of tech you can wear all day, every day, it needs to run forever. In the reddit commentary about the build, the maker also mulled overlaying the “sharp” LEDs with a ring of diffuser plastic or paper. This would still let their glow shine through, while stopping the sharp corners of the components from catching on clothing or on the wearer’s skin.

There’s also the matter of a strap to think about. I’d be up for seeing a Raspberry Pi-themed watch strap. You could laser cut some iconography onto a leather-look strap. Maybe something like we have on the windows of our Maker Lab (below) in Pi Towers.