clock hacks

997 Articles

The WalMart Atomic Clock

February 14, 2026 by 6 Comments

In the realm of first-world problems, your cheap wall clock doesn’t keep time, so you have to keep setting it. The answer? Of course, you connect it to NTP and synchronize the clock with an atomic time source. If you are familiar with how these generic quartz clock movements work, you can probably guess the first step is to gut the movement, leaving only the drive motor.

The motor is somewhat like a stepper motor. The ESP8266 processor can easily control the clock hands by sending pulses to the motor. The rest is simple network access and control. If the network time is ahead, the CPU gooses the clock a little. If it is behind, the CPU stalls the clock until it catches up.

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Restoration Of Antique Clock With Unique Oscillator

February 13, 2026 by 8 Comments

The classic design of a mechanical clock generally consists of a display, a way to store energy, a way to release that energy at regular intervals, and a mechanism to transmit it where it needs to go. Most of us might be imagining a pendulum or a balance wheel, but there have been many other ways to maintain a reliable time standard with a physical object beyond these two common methods. This clock, for example, uses a rolling ball bearing as its time standard and [Tommy Jobson] discusses its operation in depth during a restoration.

The restoration of this clock, which [Tommy] theorizes was an amateur horological project even when it was new, starts by dismantling the clock nearly completely. The clock was quite dirty, so in addition to being thoroughly cleaned it also needed a bit of repair especially involving a few bent pins that stop the table’s rotation. These pins were replaced with stronger ones, and then everything in the clock’s movement was put back together. The tray carrying the ball bearing needed to be cleaned as well, and [Tommy] also added a lacquer to help preserve the original finish as long as possible. From there it was time to start calibrating the clock.

The ball bearing itself rolls back and forth along an inclined plane on a series of tracks. When it gets to the end it hits a lever which lets a bit of energy out of the movement, tilting the table back in the other direction to repeat the process. This is a much more involved process for getting an accurate time interval than a pendulum, so [Tommy] had a lot of work to do here. But in the end he was able to bring it back to life with an accuracy fairly close to a pendulum clock.

Ball bearings are a pretty popular medium for clock builds even in the modern era. This one uses them in a unique display, and a more recent version goes even further by using marbles to display digits directly.

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A Simple Desktop Pomodoro Timer

February 7, 2026 by 7 Comments

Pomodoro timers are a simple productivity tool. They help you work in dedicated chunks of time, usually 25 minutes in a sitting, before taking a short break and then beginning again. [Clovis Fritzen] built just such a timer of his own, and added a few bonus features to fill out its functionality.

The timer is based around the popular ESP32-S2 microcontroller, which has the benefit of onboard WiFi connectivity. This allows the project to query the Internet for things like time and date updates via NTP, as well as weather conditions, and the value of the Brazilian Real versus the American dollar. The microcontroller is paired with an SHT21 sensor for displaying temperature and humidity in the immediate environment, and an e-paper display for showing timer status and other relevant information. A button on top of the device allows cycling between 15, 30, 45, and 60 minute Pomodoro cycles, and there’s a buzzer to audibly call time. It’s all wrapped up in a cardboard housing that somehow pairs rather nicely with the e-paper display aesthetic.

If Pomodoro is your chosen method of productivity hacking, a project like this could suit you very well. We’ve featured a few similar builds before, too. Continue reading “A Simple Desktop Pomodoro Timer” →

Binary And Digital Gradients For Telling Time

January 21, 2026 by 8 Comments

Creative clocks are a dime a dozen, even clocks that use binary have been created in nearly every format. [typo] promises a clever adaptation to the binary format, and it promises a more usable display. Using a combination of both traditional binary and digital gradients creates a usable and yet still nerdy fun clock.

[typo]’s clock fits the traditional binary counting method with the hours on the left side of its face. On the other hand, its right side presents a lighting gradient depending on the completion of the hour. While this is simple in principle, [typo] chose to correct what many don’t consider when deploying visual gradients. The human eye doesn’t see everything exactly as it is, which creates a rough logarithmic curve that gets corrected for in the binary/digital hybrid clock.

If you want something more mobile and still have that smidge of difficult time telling you, check out this minimalist wrist watch!

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The Time Clock Has Stood The Test Of Time

January 8, 2026 by 32 Comments

No matter the item on my list of childhood occupational dreams, one constant ran throughout: I saw myself using an old-fashioned punch clock with the longish time cards and everything. I now realize that I have some trouble with the daily transitions of life. In my childish wisdom, I somehow knew that doing this one thing would be enough to signify the beginning and end of work for the day, effectively putting me in the mood, and then pulling me back out of it.

But that day never came. Well, it sort of did this year. I realized a slightly newer dream of working at a thrift store, and they use something that I feel like I see everywhere now that I’ve left the place — a system called UKG that uses mag-stripe cards to handle punches. No it was not the same as a real punch clock, not that I have experience with a one. And now I just want to use one even more, to track my Hackaday work and other projects. At the moment, I’m torn between wanting to make one that uses mag-stripe cards or something, and just buying an old punch clock from eBay.

I keep calling it a ‘punch clock’, but it has a proper name, and that is the Bundy clock. I soon began to wonder how these things could both keep exact time mechanically, but also create a literal inked stamp of said time and date. I pictured a giant date stamper, not giant in all proportions, but generally larger than your average handheld one because of all the mechanisms that surely must be inside the Bundy clock. So, how do these things work? Let’s find out.

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The clock and the rebuilt calculator from which its VFD was donated.

An RPN Calculator And A Bonus VFD Clock From Casio Revival

January 5, 2026 by 15 Comments

Have you heard the saying “the problem is the solution”? It seems to originate in the permaculture movement, but it can apply equally well to electronics. Take the problem [shiura] had: a Casio Mini CM-602 that had let out the magic smoke. The solution was a twofer: rebuild the Casio into a modern number cruncher with Reverse Polish Notation (RPN), and save the Vacuum Fluorescent Display (VFD) for a gorgeous WiFi clock.

[shiura]’s write-up includes a helpful guide for reverse engineering the pins on this sort of VFD, if you don’t happen to have the same model calculator (or VFD tube) they’re working with. If you’ve done this sort of thing, you know what to expect: power it up and kill power to the pins, one by one, to map out which segments or characters go out, thereby identifying the anodes and grid electrodes. The cathodes had already been ID’d from looking at the PCB. After that it’s just a matter of wiring the VFD to an ESP32 via a transistor array to get the voltages right, and voila! Clock. The code and case design files for this clock — including an editable .blend — are available via GitHub.

The calculator half of the project is an incredibly elegant hack that relies on the fact that the Casio’s CPU has the same pin pitch as modern micros: 2.54 mm, or 0.1″, so an RP2040 zero can sit in the footprint of the original CPU, scanning the keypads with its GPIO. Then an I2C display is separately wired up to replace the clockified VFD. Perhaps some driver circuitry for the VFD died, or [shiura] salvaged the display before deciding to save the calculator, because otherwise we see no reason why this brain transplant couldn’t be done while keeping the original display. Admittedly having two lines on the display instead of one make the “new” calculator a tad more usable. The code for that is also available on GitHub, and while the readme is in Japanese, machine translations have gotten pretty good and the code is quite readable on its own.

Longtime readers will likely be familiar with [shiura]’s work, with a number of finely crafted clocks having been featured from the Japanese maker, along with vintage pocket computer repairs. Bringing both together makes this twin hack particularly on-brand.

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Qron0b: A Minimalist, Low-Power BCD Wristwatch

January 2, 2026 by 19 Comments

Over the decades we have seen many DIY clocks and wrist watches presented, but few are as likely to get you either drawing in the crowds, or quietly snickered at behind your back, as a binary watch of some description does. A wrist watch like [qewer]’s qron0b project which also uses BCD encoding to display the current time is among our more rare project types here, with us having to go all the way back to 2018 for a similar project as well as a BCD desk clock.

As is typical, a single CR2032 coin cell powers the entire PCB, with an ATtiny24A or compatible as the MCU, a DS1302 RTC and the requisite 4×4 LED matrix to display the hours and minutes. Technically three LEDs are unneeded here, but it looks nicely symmetrical this way, and the extra LEDs can be used for other tasks as the firmware is expanded from the current setting and reading of the time.

The AVR C firmware can be found in the above linked GitHub repository, along with the KiCad PCB project and FreeCAD design files for the watch body. The body accepts a 22 mm GT2/GT3-style watch strap to complete the assembly. With a single CR2032 you’re assured of at least a few months of runtime.