Description
Gemtronic is a smart ring that turns a tiny round LCD screen into a new kind of gem. It is both an avant-garde piece of jewelry and a piece of consumer electronics that fits real function into an extremely tight space: an ESP32-C3, a round LCD and its sensors deliver gesture controls, mini-games, a step-driven digital pet and Bluetooth phone pairing.
During the event (September to October 5), the gesture controls got better: tilt to flip through menus, air-tap to select, double air-tap to go back, and the more complex functions got their own menu pages. The electronics moved to a redesigned rigid PCB, its schematic finalized with help from experienced hardware engineers and professors, with Type-C and battery power added; the demo prototype was rebuilt with USB-C and strain relief. The shell was redesigned too, starting in Tripo and then given a more precise mechanical layout in Rhino.
Before the event, the author had made a first version in spring 2026: a "Tamagotchi in a ring" with simple animations and gestures, its ESP32-C3 and round LCD still on a breadboard with the motion sensors tested and no battery, built around an FPC wrapped around the band and a different shell taken from Tripo to Nomad.
It is a gift for people who want playful tech they can wear as jewelry. The firmware is built on Espressif's Arduino-ESP32 core and the NimBLE Bluetooth stack, with coding assistance from Claude Code and Codex.
How Tripo was used
Gemtronic's shell design starts in Tripo.
- The new shell for this entry: started in Tripo, then given a more precise mechanical layout in Rhino.
- The earlier shell, made before the event: also started in Tripo, then finished in Nomad.
