A Custom PCB For The Casio G-Shock

June 23, 2026 by Tom Nardi 13 Comments

With the PCB fabrication services available to the modern hobbyist, it’s become increasingly common to see replacement boards designed for all sorts of devices. Even so, it’s sometimes still a little difficult to believe that we’re at the point where hardware hackers are now producing advanced replacement PCBs for commercial wristwatches such as this drop-in upgrade for the iconic Casio G-Shock by [David Volovskiy].

Honestly, we’d have been impressed if the thing could just tell the time. But the replacement board combined with the open source firmware brings new capabilities that far exceed anything the G-Shock was capable of originally. The upgraded watch now offers several applications, such as a pedometer and a number of games including simplified versions of Blackjack and Wordle. The watch can tell you the phase of the Moon, calculate sunrise and sunset, and display values pulled from the internal thermometer.

Even if you don’t have a G-Shock in need of a new PCB, [David] has put together a web-based emulator that lets you play around with the firmware. The online tool that lets you visualize how the watch’s LCD is mapped is also very slick. For those interested in getting a board of their own, you can join the project’s Discord server and get your name on the list for an upcoming production run.

If some of this sounds familiar, it’s because [David] based his project on [Joey Castillo]’s Sensor Watch, which is a replacement PCB for the Casio F-91W. With these two projects available for others to build from, one wonders how many other Casio watches might get their own upgraded hardware in the future.

The Repair Nightmare That Are Smart Rings

June 20, 2026 by Maya Posch 21 Comments

In the quest to make every wearable device ‘smart’, a lot of electronics along have to be crammed in very small spaces, along with ways to make them resistant to environments that our bodies do not mind, like getting hit by a rainstorm or simply washing our hands. These two factors combined make especially devices like smart rings an interesting case study for repairability, with [iFixit] recently taking apart a modern Oura smart ring to assess its e-waste factor after the built-in battery dies.

The tiny 10.5 mAh Lipo cell in the Oura Ring 5. (Credit: iFixit)

The subject of the teardown video is the Oura Ring 5, a $400 smart ring that’s designed to track your vitals much like a wrist-worn fitness tracker — just in a much smaller package. This metal-and-epoxy sandwich can definitely survive a good rain shower and washing of hands, but to get to the internals rather forceful methods were needed, unlike previous Oura and Samsung smart rings where some applied heat was enough.

In the Ring 5’s case even more heat was needed to make the inner ring start to slide out, but by that point the Li-ion battery inside had already popped from the heat. The inner ring then got stuck and more violence was required to continue the disassembly and get to the super-tiny, 10.5 mAh battery. Of course, at this point the smart ring really won’t be getting back together, never mind still work or be waterproof, which is a central issue with these smart rings.

With the EU’s February 2027 deadline for user-replaceable batteries looming on the horizon, it’ll be interesting to see whether devices like this can squeeze into an exception category, or whether manufacturers will have to massively redesign or stop selling these devices to this rather large market. So far this particular regulation has already forced Nintendo to make a special Switch 2 console for the EU.

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Custom Watch Is On The Case

June 13, 2026 by Al Williams 14 Comments

We were excited to see [Z0hn]’s project about 3D printing a custom watch from scratch — both because it was an exciting idea, and because the pictures looked great. While we still liked the project, we quickly realized it wasn’t really printing a watch so much as it was printing a case that holds an off-the-shelf movement. But it still looked great.

Many homebrew watches are cool and fine to wear to your next hackerspace board meeting. But this watch wouldn’t raise an eyebrow out among the normal public. Conventional watches use press-fit backs, tiny screws, or make the back screw into the housing. None of those are great for 3D printing, so this watch uses a bayonet connector, which is easy to create, robust, and reliable.

The watch looks easy to modify, so if you don’t like, for example, the unusual crown placement, you can change it. The movement is a Miyota 8N24 and, of course, the crystal is off-the-shelf, too.

While not exactly a printed watch, it was still pretty cool, and there are lessons to be learned here if you want to pull off the same feat. Or just go full on hacker. You could, too, try your hand with an open source movement.

After The Dust Settles: Building Pebble Apps

June 1, 2026 by Bryan Cockfield 17 Comments

For a piece of wearable technology, Pebble has had a fairly “rocky” history. One of the most successful Kickstarters of its era, it went on to get acquired by FitBit, quietly shelved by them, then acquired by Google and open-sourced, where it’s now somewhat back in the hands of its original creator. Its new open source nature means that regular people can develop for these popular watches again, and [Coconauts] have developed a guide for these watches, new and old.

The original watches had to be coded using C, which is a fundamental language but one that generally isn’t used much in the modern world outside of embedded systems and other areas where efficieny is important. C does much less hand-holding than modern languages, so there are a number of things to keep an eye on when coding for these watches that languages like Rust, Go, and Python handle on their own. Regardless, the two-person team recently built a pair of apps for the Pebble platform as part of an app-making contest, one which notifies the user that the watch is charged to 80%, and another that shows an interactive kitten on the watch’s face.

Both of the apps are available from the Pebble app repository, and from there the source code can be found on respective GitHub pages if you’re looking for some examples to dust off old C skills. If you happen to have an old Pebble watch or always wanted one but didn’t want to deal with FitBit, now might be a good time to get them out and start tinkering around with it since it’s now in the open-source domain.

Jacket Turned Cyberpunk Wearable OLED Display

May 22, 2026 by Zoe Skyforest 18 Comments

If you’ve played Cyberpunk 2077, you might have seen the rad jacket that has a screen in the collar. Once upon a time, such a thing would be solely the preserve of science fiction—you certainly wouldn’t be achieving that look with cathode ray tubes, that much is for sure. However, technology has advanced to the point where [Zibartas] was able to produce just such a jacket in real life.

The key to the build is the advent of the flexible OLED screen. [Zibartas] was able to source four such panels in a smartphone-like aspect ratio, which came in at the hefty price of $300 each. Two Raspberry Pi 4s were enlisted to drive two screens each. The older model Pi was chosen as it was capable of achieving a neat hack to better play smooth video across two displays. A rudimentary sync system was whipped up using GPIO pins to keep video from both Pis playing together. From there, it was simply a matter of figuring out how to create a structure to hold the screens within the large collar of the scratch built cyberpunk-styled jacket. As it turns out they don’t actually flex much in the final install, as they’re held in a 3D printed structure to keep them safe from damage.

The final result is quite something, very accurately recreating the jacket from the game itself. While technically a simple build, actually pulling it off required some delicate work and smart design decisions to make it practical to wear. We’ve featured some other fun jackets over the years, too.

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Building A Pip Boy Themed Smartwatch

May 19, 2026 by Zoe Skyforest 9 Comments

One of the problems with good science fiction is that it introduces us to all kinds of cool devices that we can’t actually have in real life. [Huy Vector] has tried to fix that a little with this fantastic smartwatch build inspired by everybody’s favorite wrist computer from the Fallout series.

The build is based around a Xiao ESP32-S3 board, which hosts the capable microcontroller and has all that useful wireless connectivity built in. It’s hooked up to a MAX30102 heart rate sensor to collect the wearer’s vital signs, as well as a 1.54″ LCD screen for displaying the fantastic Pip Boy themed interface. Power is courtesy of a small lithium-ion cell tucked in behind the display. A little copper tubing and brass hardware helps tie everything together, with the latter serving as capacitive touch points for controlling the device. A simple leather watch strap completes the build.

It’s a bit of a diversion from the classic Pip Boy design, in that it’s a small smartwatch instead of a chunky device that takes up most of the wearer’s forearm. However, this isn’t so bad in reality—it’s far more practical while still rocking those classic green-on-black graphics that we all love so much.

If you’re craving a more authentic Pip Boy recreation, we’ve featured a few of those, too.

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LightInk, A Solar Powered ESP32 Smartwatch

May 5, 2026 by Tyler August 11 Comments

There’s something about the ESP32 family of microcontrollers and timekeeping. We probably see it in clocks as often as we do anything else; we also probably see more clocks with one as the beating heart than any of the many other possible timekeeping options.

[Daniel Ansorregui]’s LightInk watch is no different in that regard — but it is very different in one important detail, because unlike most other smartwatch designs, you won’t have to worry about battery life. Outside of gloomiest Gotham, its built-in solar panel should be able to keep it charged.

That’s for a few reasons. The obvious one is the e-ink display, which only takes a sip of power during updates. That’s hardly unique to [Daniel]’s projec t– he quite explicitly calls out the Watchy project, which we featured previously, as where he got the idea of putting e-ink and an ESP32-PICO together on his wrist. What is unique is the delightful hack [Daniel] is using to minimize power usage, which is our favorite part.

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