Malfunctional Timekeeping With The Vetinari Clock

April 1, 2025 by 26 Comments

Lord Vetinari from the Discworld series is known for many things, but perhaps most of all a clock that doesn’t quite keep continuous time. Instead, it ticks away at random increments to infuriate those that perceive it, whilst keeping regular time over the long term. [iracigt] decided to whip up a real world version of this hilarious fictional timepiece.

The clock itself is an off-the-shelf timepiece purchased from Target for the princely sum of $5. However, it’s been deviously modified with an RP2040 microcontroller hidden away inside. The RP2040 is programmed to tick the clock at an average of once per second. But each tick itself is not so exact. Instead, there’s an erraticness to its beat – some ticks are longer, some shorter, in the classic Vetinari style. [iracigt] explains the nitty gritty of how it all works, from creating chaos with Markov chains to interfacing the RP2040 electronically with the cheap quartz clock movement.

If you’ve ever wanted to build one of these amusements yourself, [iracigt’s] writeup is a great place to start. Even better, it was inspired by an earlier post on these very pages! We love to see the community riff on a theme, and we’d love to see yours, too – so keep the tips coming, yeah? Video after the break.

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Lord Vetinari’s Clock Strikes Again

February 12, 2013 by 15 Comments

vetinari

Inspired by the maddening timepiece from Discworld, this clock keeps time, but anyone watching the seconds tick by may be mentally unstable for it. [Renaud Schleck] built the stuttering clock using very few components. He undertook the build after being inspired by the version which [Simon Inns] built.

The clock itself is a run-of-the-mill item which uses one battery to keep time. We’re always impressed by how these dirt-cheap things remain so accurate over the long haul — but we digress. The method of attack uses coil injection to drive the hands. [Renaud] used one of the microcontrollers from the MSP430 Launchpad, along with the clock crystal which also shipped with the kit, to gain control of the mechanism. The crystal triggers an interrupt which does the actual time-keeping. The seconds hand is driven rather sporadically based on an algorithm explained in his write-up.

You can watch the uneven ticking in the video after the break. Despite that visually disturbing functionality, the short and long ticks balance each other and the correct time continues to be displayed.

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Vetinari Clock Will Drive You Insane

October 6, 2011 by 47 Comments

Sometimes we need more psy ops in our life. Being an eminent fan of the Discworld series, Reddit user [rdmiller3] decided he needed to build Lord Vetinari’s clock. This fictional clock was placed in the waiting room for Lord Vetinari in several of the Discworld books. Although the clock keeps accurate time overall, it sometimes tics irregularly and out of sync. The reason? To whittle away the minds of whoever waits for Lord Vetinari.

The build uses a standard battery-powered analog clockwork. The ticking mechanism is just a magnet mounted inside a coil driven iron core. The coil leads were disconnected from the clock circuit and connected to digital inputs of an Arduino. With a few random() calls, the clock keeps accurate but random time.

Unfortunately, the clock stopped working after a few weeks because the 5 V from the Arduino was, “pounding it way too hard.” [rdmiller3] says a few resistors and LEDs for the voltage drop would make for a more reliable circuit, though. Check out the hard to watch video of the clock in action after the break.

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2025 One Hertz Challenge: Timekeeping At One Becquerel

August 18, 2025 by 23 Comments

The Becquerel (Bq) is an SI unit of radioactivity: one becquerel is equivalent to one radioactive decay per second. That absolutely does not make it equivalent to one hertz — the random nature of radioactive decay means you’ll never get one pulse every second — but it does make it interesting. [mihai.cuciuc] certainly thought so, when he endeavored to create a clock that would tick at one becquerel.

The result is an interesting version of a Vetinari Clock, first conceived of by [Terry Pratchett] in his Discworld books. In the books, the irregular tick of the clock is used by Lord Vetinari as a form of psychological torture. For some reason, imposing this torture on ourselves has long been popular amongst hackers.

Without an impractical amount of shielding, any one-becquerel source would be swamped by background radiation, so [mihai] had to get creative. Luckily, he is the creator of the Pomelo gamma-ray spectroscope, which allowed him to be discriminating. He’s using an Am-241 source, but just looking for the characteristic 59.5 KeV gamma rays was not going to cut it at such a low count rate. Instead he’s using two of the Pomelo solid-state scintillation as a coincidence detector, with one tuned for the Am-241’s alpha emissions. When both detectors go off simultaneously, that counts as an event and triggers the clock to tick.

How he got exactly one becquerel of activity is a clever hack, too. The Am-241 source he has is far more active than one decay per second, but by varying the distance from the gamma detector he was able to cut down to one detection per second using the inverse square law and the shielding provided by Earth’s atmosphere. The result is a time signal that is a stable one hertz… if averaged over a long enough period. For now, anyway. As the Am-241 decays away, its activity decreases, and [mihai] admits the clock loses about 0.4 seconds per day.

While we won’t be giving the prize for accuracy in this contest, we are sure Lord Vetinari would be proud. The Geiger-counter sound effect you can hear in the demo video embedded below is great touch. It absolutely increases the psychic damage this cursed object inflicts.

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Sneaky Clock Displays Wrong Time If It Catches You Looking

February 23, 2023 by 20 Comments

We have a soft spot for devices that subvert purpose and expectation, and that definitely sums up [Guy Dupont]’s Clock That Is Wrong. It knows the correct time, but whether or not it displays the correct time is another story. That’s because nestled just above the 7-segment display is a person sensor module, and when it detects that a person is looking towards it, the clock will display an incorrect time, therefore self-defeating both the purpose and primary use case of a clock in one stroke.

The person sensor is a tiny board with tiny camera that constantly does its best to determine whether a person is in view, and whether they are looking towards the sensor. It’s a good fit for a project like this, and it means that one can look at the clock from an oblique angle (meaning one is out of view of the sensor) and see the correct time. But once one moves in front of it, the time changes. You can watch a brief video of it in action in this Twitter thread.

One interesting bit is that [Guy] uses an ESP32-based board to drive everything, but had some reservations about making a clock without an RTC. However, he found that simply syncing time over the network every 10 minutes or so using the board’s built-in WiFi was perfectly serviceable, at least for a device like this.

This reminds us a little of other clocks with subtly subversive elements, like the Vetinari Clock which keeps overall accurate time despite irregularly drifting in and out of sync. Intrigued by such ideas? You’re not alone, because there are even DIY hobby options for non-standard clock movements. Adding the ability to detect when someone is looking directly at such a device opens up possibilities, so keep it in mind if it’s time for a weekend project.

Hackaday Prize Entry: A Clock For Alternate Timebases

July 10, 2015 by 15 Comments

There is a strange clock in the waiting room of Lord Vetinari, Patrician of Ankh-Morpork. While this clock keeps accurate time overall, the ticks and tocks are out of sync, occasionally missing a tick altogether. The net effect is one of turning one’s brain into a sort of porridge.

Yes, a Vetinari Clock has made its way into The Hackaday Prize. This isn’t a clock that’s random yet accurate over long time spans; this is a complete replacement for run-of-the-mill clock movements you can find at any craft store.

In addition to the Vetinari Clock, [Nick Sayer]’s Crazy Clock can be programmed as a sidereal clock (3m 56s fast per day), a Martian clock (39m 36s slow per day), and a tidal clock (50m 28s slow per day), as well as some ‘novelty’ modes that still have 86400 ticks per day ranging from subtle to ‘clown car’ levels of craziness.

[Nick] is gunning for the ‘best product’ category for the Hackaday Prize, and for that he’s designing a board to be a direct replacement for the board in a Quartex Q80 clock movement. With this new board, [Nick] can replace the electronics in this movement in just a few minutes. Being built around an ATtiny45 means it’s infinitely hackable. A clock with this movement would be a great product, although judging from the video below, not one we would want to be around all day.

The 2015 Hackaday Prize is sponsored by:

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Transparent Alarm Clock Runs Linux

May 30, 2015 by 24 Comments

[Benoit] was using an extremely old alarm clock which normally ran on mains power, and he plugged it in to his computer’s UPS to keep it operational during power outages. He noticed that when the UPS switched on that the clock would run fast, though, and apparently it was keeping time by watching the power system frequency. To solve this problem he created his own feature-dense clock which runs Linux.

This alarm clock has everything: seven-segment displays housed in clear epoxy, a touch interface, battery backup, the ability to retrieve the time from an NTP server, and a web interface to change the clock’s settings over the network. That was a large part of [Benoit]’s decision to have the clock run Linux; the network capabilities add a lot of functionality to the clock like the ability to send commands to other devices at particular times. The clock runs on an Aria G25 SOM and has a custom case that looks very professional.

We’re suckers for a high-quality clock builds here, and [Benoit]’s most recent project hits all of our buttons. Even though it doesn’t currently drive people insane or tell confusing time, the Linux and networking capabilities could certainly open up options!