Innovative Clock Uses Printed Caustic Lens

January 20, 2025 by Lewin Day 13 Comments

Hackers and makers have built just about every kind of clock under the sun. Digital, analog, seven-segment, mechanical seven-segment, binary, ternary, hexadecimal… you name it. It’s been done. You really have to try to find something that shocks us… something we haven’t seen before. [Moritz v. Sivers] has done just that.

Meet the Caustic Clock. It’s based on the innovative Hollow Clock from [shiura]. It displays time with an hour hand and a minute hand, and that’s all so conventional. But what really caught our eye was the manner in which its dial works. It uses caustics to display the clock dial on a wall as light shines through it.

If you’ve ever seen sunlight reflect through a glass, or the dancing patterns in an outdoor swimming pool, you’ve seen caustics at play. Caustics are the bright patterns we see projected through a transparent object, and if you shape that object properly, you can control them. In this case, [Moritz] used some GitHub code from [Matt Ferraro] to create a caustic projection clockface, and 3D printed it using an SLA printer.

The rest of the clock is straightforward enough—there’s some WS2812 LEDs involved, an Arduino Nano, and even an RP2040. But the real magic is in the light show and how it’s all achieved. We love learning about optics, and this is a beautiful effect well worth studying yourself.

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Hackaday Podcast Episode 304: Glitching The RP2350, Sim Sim Sim, And A Scrunchie Clock

January 17, 2025 by Dan Maloney 1 Comment

It’s podcast time again, and this week Dan sat down with Elliot for a look back at all the cool hacks we’ve written about. We started off talking about Hackaday Europe, which is coming up in March — seems unlikely that it’s just around the corner, but there it is. There’s also good news: the Hack Chat is back, and we started things off with a bang as Eben Upton stopped by to talk all things Pi. Separately, we talked about fault injection attacks, including how to find the hidden cup of 0xC0FFEE in an RP2350.

We saw a very cool piece of LED jewelry that does a fluid simulation, a direct conversion radio that’s all laid out in front of you, and the scrunchiest mechanical digital clock you’ll ever see. We saw blinkenlights for blinkenlights’ sake, all the ways to put threads in your prints, and how to ditch to coax and wire up your antennas with Cat 6 cable. Plus, it’s an Al Williams twofer in the Can’t-Miss Articles, with a look back at life before GPS and how you can tune into digital ham radio, no radio required.

Download the zero-calorie MP3.

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Electromechanical 7-Segment Display Is High Contrast Brilliance

January 13, 2025 by Lewin Day 11 Comments

The seven-segment display is most well known in LED form, but the concept isn’t tied to that format. You can build a seven-segment display out of moving parts, too. [tin-foil-hat] has achieved just that with a remarkably elegant design.

As you might expect, the build relies heavily on 3D-printed components—produced in white and black plastic to create a high-contrast display. It’s a simple choice that makes the display easy to read in a wide variety of lighting conditions, and far less fussy than toying with LEDs and diffusers and all that.

Actuation of each display segment is achieved electromagnetically. Effectively, each segment behaves like a flip dot, with the orientation controlled by energizing one of two electromagnets per segment. Controlling the electromagnets is an ESP32, which is hooked up to the various segments via a Darlington transistor array, with multiplexing used to minimize the number of IO pins required. A shift register was also employed to let the microcontroller easily drive four of these electromechanical digits.

It’s a simple build, well explained—and the final result is aesthetically pleasing. We’ve seen a few builds along these lines before, albeit using altogether different techniques. Lots of different techniques, in fact! Video after the break.

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Split-Flap Clock Flutters Its Way To Displaying Time Without Numbers

November 5, 2024 by Donald Papp 18 Comments

Here’s a design for a split-flap clock that doesn’t do it the usual way. Instead of the flaps showing numbers , Klapklok has a bit more in common with flip-dot displays.

It’s an art piece that uses custom-made split-flaps which flutter away to update the display as time passes. An array of vertically-mounted flaps creates a sort of low-res display, emulating an analog clock. These are no ordinary actuators, either. The visual contrast and cleanliness of the mechanism is fantastic, and the sound they make is less of a chatter and more of a whisper.

The sound the flaps create and the sight of the high-contrast flaps in motion are intended to be a relaxing and calming way to connect with the concept of time passing. There’s some interactivity built in as well, as the Klapklok also allows one to simply draw on it wirelessly with via a mobile phone.

Klapklok has a total of 69 elements which are all handmade. We imagine there was really no other way to get exactly what the designer had in mind; something many of us can relate to.

Split-flap mechanisms are wonderful for a number of reasons, and if you’re considering making your own be sure to check out this easy and modular DIY reference design before you go about re-inventing the wheel. On the other hand, if you do wish to get clever about actuators maybe check out this flexible PCB that is also its own actuator.

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Clockwork Rover For Venus

October 26, 2024 by Danie Conradie 28 Comments

Venus hasn’t received nearly the same attention from space programs as Mars, largely due to its exceedingly hostile environment. Most electronics wouldn’t survive the 462 °C heat, never mind the intense atmospheric pressure and sulfuric acid clouds. With this in mind, NASA has been experimenting with the concept of a completely mechanical rover. The [Beardy Penguin] and a team of fellow students from the University of Southampton decided to try their hand at the concept—video after the break.

The project was divided into four subsystems: obstacle detection, mechanical computer, locomotion (tracks), and the drivetrain. The obstacle detection system consists of three (left, center, right) triple-rollers in front of the rover, which trigger inputs on the mechanical computer when it encounters an obstacle over a certain size. The inputs indicate the position of each roller (up/down) and the combination of inputs determines the appropriate maneuver to clear the obstacle. [Beardy Penguin] used Simulink to design the logic circuit, consisting of AND, OR, and NOT gates. The resulting 5-layer mechanical computer quickly ran into the limits of tolerances and friction, and the team eventually had trouble getting their design to work with the available input forces.

Due to the high-pressure atmosphere, an on-board wind turbine has long been proposed as a viable power source for a Venus rover. It wasn’t part of this project, so it was replaced with a comparable 40 W electric motor. The output from a logic circuit goes through a timing mechanism and into a planetary gearbox system. It changes output rotation direction by driving the planet gear carrier with the sun gear or locking it in a stationary position.

As with many undergraduate engineering projects, the physical results were mixed, but the educational value was immense. They got individual subsystems working, but not the fully integrated prototype. Even so, they received several awards for their project and even came third in an international Simulink challenge. It also allowed another team to continue their work and refine the subsystems. Continue reading “Clockwork Rover For Venus” →

A Look Inside The Geochron Clock

May 31, 2024 by Dan Maloney 6 Comments

There are plenty of cool clocks out there, and maps by their very essence are cool, too. But a map that’s also a clock — or is it a clock that’s also a map? — has to be the coolest thing ever.

Of course we’re talking about the Geochron, a world clock that makes the relationship between the Earth and the Sun clear and has graced the offices of executives who want to impress visitors with the global nature of their importance for decades. [Attoparsec] has long coveted one of these electromechanical beauties, and when a used one popped up online for a pittance, at least compared to what they cost new, he jumped at the chance.

The Geochron he ended up with was in need of some TLC, but surprisingly little considering its mid-1980s vintage. The real treat in the video below is getting to see how these wonderful devices work. They’re basically simple slide projectors. While we here in the future would simply do everything in software on a nice flat-screen display, the base map, night-day terminators, and calendar are all contained on transparent elements that move under the power of a synchronous motor across a lighted platen. The analemma display is particularly cool; an indicator tracks the Sun’s position over the Earth with a cam that encodes the equation of time in its shape, moving through its familiar bi-lobed loop as the seasons progress.

Any clock that comes with a set of blueprints for installation purposes is alright in our book, and kudos to [Attoparsec] for landing this prize and getting it back in shape. His description of it as “the greatest clock of all time” is apt, but perhaps with a little competition. Or maybe a lot.

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Simple NTP Clock Uses Custom RGB 7-Segment Displays

March 17, 2024 by Lewin Day 14 Comments

A great majority of hackers build a clock at some point. It’s a great way to get familiar with electronics and (often) microcontrollers, and you get to express some creativity along the way. Plus, you get something useful when you’re done! [Tadas Ustinavičius] recently trod this well-worn path and built a neat little NTP clock of their own.

The build uses an ESP 12F as the core of the operation. It’s charged with querying an NTP time server via its WiFi connection in order to maintain accurate timekeeping around the clock. For display, it drives a series of custom 7-segment displays that [Tadas] built using 3D-printed housings. They use WS2812B addressable LEDs and thus can display a rainbow of colors.

For initial configuration, the phone creates its own WiFi hotspot with a web interface for changing settings. Once configured, it connects to the Internet over WiFi to query an NTP server at regular intervals.

It’s a simple build that does a simple job well. Projects like these can be very valuable, as they teach you all kinds of useful skills. If you’ve been working on your own clock design, don’t hesitate to let us know. You can use a microcontroller, relays, or even a ball.