ChronoHackers

A 3D-Printed Watch Case With a Bayonet-Mount Back
A fully 3D-printed watch case built around an off-the-shelf Miyota 8N24 movement, using a twist-lock bayonet back instead of fussy threads.
Read more
Sahko repurposed an analog coil meter movement as a watch face, driven by a Raspberry Pi Pico through a DAC, in a CNC-milled aluminum case.

Vishalsoniindia built an RP2040 smartwatch around a Waveshare round touch display, with a Tinkercad-designed case and full build files for anyone who wants to follow along.

drfailov's ESP32-S2 wearable runs for two weeks on a charge and leans on the unglamorous engineering — battery life, durability, backlighting — that most DIY smartwatch demos skip.

Huy Vector turned copper tubing and brass hardware into both the housing and the touch controls for a Fallout-inspired wrist computer.

Henner Zeller built a wristwatch that displays the time by charging glow-in-the-dark tape with a UV LED array as it scrolls past, spotted at Supercon 2024.

Redditor CoreMemory_156 built a from-scratch smartwatch on a homemade PCB — heart rate sensor, Tetris clone, and all — specifically so they'd know exactly what their watch is doing.

A replacement PCB and firmware fork turns a stock Casio G-Shock DW-5600 into a fully programmable, open-hardware watch.

Daniel Ansorregui's ESP32 smartwatch pairs a built-in solar panel with e-paper and a clever RTC-memory boot trick to stretch run time to months.

John Raffaelli machined nearly every part of a working mechanical watch movement himself, buying only the jewels, crystal, strap, hairspring, and mainspring.

Aaron Christophel rebuilt an SDK from scratch for Xiaomi's undocumented wearable chip, then proved it out by getting DOOM running on the band's screen.

The Openmovement foundation released complete STEP files for a serviceable Swiss-lever escapement movement, aimed at watchmaking schools and new makers rather than collectors.

Hansel Kay designed an ESP32-C3 smartwatch from scratch — PCB, power regulation, and firmware — as a platform other makers can build on.

Matthew James Bellafaire built an ESP32 smartwatch designed to put full control back in the user's hands, iterating through five hardware revisions to get there.

Three makers built an ESP32 fitness tracker where a hand-drawn pixel character mimics your current activity level instead of just logging steps.


ddominik's open-source RP2040 smartwatch skips fitness tracking in favor of a 5mW laser pointer, retro PWM tunes, and other deliberately unnecessary features.

Andrew Childs built his son a custom ESP32-S3 smartwatch that pulls in Dexcom CGM data over BLE, after deciding a strapped-on Apple Watch wasn't the right fit for a nine-year-old.

TallmanLabs built a piezo-microphone timegrapher that measures a mechanical watch's rate, amplitude, and beat error without the cost of a commercial acoustic probe.

What started as Umut Sevdi's senior engineering project is now open-source bare-metal firmware that turns an RP2040 board into a smartwatch with a companion Android app.
What ChronoHackers is, why it exists, and what you will find here
Know a maker?
Tell us about a project worth featuring.
If someone, somewhere, is building something remarkable at their bench — send us a link. We read every tip and follow up on the ones that fit.