An electromechanical clock based on sliding frames

Watch Time Slide By With This Electromechanical Clock

February 27, 2023 by Robin Kearey 13 Comments

Back in the 18th century, clockmakers were held in high esteem, as turning pieces of metal and wire into working timepieces must have seemed like magic at the time. The advent of mass production made their profession largely obsolete, but today there are several hardware hackers whom you could consider modern heirs of the craft. [Hans Andersson] is one of them, and has made a name for himself with an impressive portfolio of electromechanical clocks. His latest work, called the Time Slider, is every bit as captivating as his previous work.

The mechanical display is almost entirely made of 3D printed components. Four flat pieces of red PLA form a basic 88:88 indicator, onto which the correct time is displayed by sliding frames that black out certain pixels. Those frames are moved up and down by a rack-and-pinion system driven by stepper motors. Evertyhing is controlled by an Arduino Mega, acoompanied by a DS3231 RTC and eight ULN2003-based stepper motor drivers.

[Hans] wrote a detailed assembly guide to go along with the STL files and Arduino code, so it should be easy make your own Time Slider if you have a decent supply of PLA filament. The display takes about ten seconds to update, but the process has certain hypnotic quality to it, helped by the mechanical whirring of the stepper motors in the background. Especially the hourly change of three or four digits at once is mesmerizing, as you can see in the video embedded below.

Time Slider is the latest in [Hans]’s long line of mechanical clocks, which includes the Time Twister series that evolved from a clever Lego-based design to a neat 3D-printed model. The rack-and-pinion system can also be used to make a compact linear clock.

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A clock with an e-paper display in a 3D-printed case

Low Power Challenge: E-Paper Shelf Label Becomes Ultra-Frugal Clock

February 24, 2023 by Robin Kearey 12 Comments

Over the past two decades, e-paper has evolved from an exotic and expensive display technology to something cheap enough to be used for supermarket price tags. While such electronic shelf labels are now easy to find, actually re-using them is often tricky due to a lack of documentation. Luckily, [Aaron Christophel] has managed to reverse engineer many types of shelf labels, and he’s demonstrated the results by turning one into an ultra-low-power clock called Triink. It’s based on a 128×296 pixel e-ink display paired with an nRF52832 BlueTooth Low-Energy SoC and uses just 65 micro-amperes on average: low enough to keep it running for more than a year on a single battery charge.

A PCB for an e-ink clock — Power on the left, e-ink on the right: the custom PCB is clever and compact, too

The clock is housed in an enclosure that’s simple but effective: a 3D-printed triangular prism with a slot for the screen and space for the 18650 lithium battery. One side can be opened to access the internal components, although that’s really only needed to charge the battery. You can see how cleverly everything snaps together in the video embedded below. Continue reading “Low Power Challenge: E-Paper Shelf Label Becomes Ultra-Frugal Clock” →

Sneaky Clock Displays Wrong Time If It Catches You Looking

February 23, 2023 by Donald Papp 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.

A round clock with a color-coded face, with its name "Pingo" across it, together with a 3D animated mouse

Pingo Is An Analog Clock That Uses Colors Instead Of Hands

February 20, 2023 by Robin Kearey 8 Comments

The purpose of a clock is to show the time, obviously. But if you’ve followed Hackaday for some time, you’ll know there are about a million different ways of achieving this. [illusionmanager] added yet another method in his Pingo Color Clock, which, as the name suggests, uses color as the main indicator.

The clock’s face is divided into three concentric circular zones. The zone at the center shows the hours, while the outer ring indicates the minutes. Both change their color such that they match the zone in between, which always shows a complete rainbow, at the desired location. In the picture above for example, the magenta inner circle matches the rainbow at the 10 o’clock position, while the yellow outer circle matches it at 10 minutes past the hour, meaning it’s currently 10:10.

The rainbow ring is also moving however, and by adjusting its rotation through time you can get some interesting effects. [illusionmanager] programmed it in such a way that the outer ring is always yellow during the day, purple at night, and red at sunrise and sunset. The overall brightness is also adjusted to a day/night schedule.

As complex as the clock’s appearance may be, inside it’s quite a simple design. Nine concentric circular LED strips are driven by an ESP8266, which retrieves the time and sunrise information through its WiFi connection. A piece of translucent white acrylic acts as a diffuser, while a 3D-printed enclosure holds everything together.

Encoding the time using different colors of light has been done before in various different ways, and while we haven’t seen Pingo in real life, we believe it should be somewhat easier to read than most of those examples. It might actually form a nice complement to a recent analog LED ring clock.

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Decorative Clock Uses LED Strips To Beautiful Effect

February 9, 2023 by Lewin Day 19 Comments

Clocks used to be dowdy old things with mechanical hands and sometimes even little cuckoo birds that would pop out to chime the hour. [David] built something altogether more modern that uses shifting colors on LED strips to tell the time.

The core of the build is an ESP8266, which queries an NTP time server to keep itself synced up with the current time as accurately as possible. It then controls a WS2812B LED strip to display the time. The strip itself is hidden in a 3D-printed housing behind an opaque wooden ring, with the light from the LEDs diffusing out nicely on to the wall upon which the clock is mounted.

The display shows three “hands” in the colors it projects on the wall. The red second hand is projected inside and outside the ring. The minute hand is green, and projects outside the ring. Meanwhile, the hour hand is blue, and projects inside the ring. Without any numerical markings, you won’t get an exact reading of the time, but you can figure it out closely enough. As a bonus, the clock looks like a stylish light-based wall sculpture and your guests may not even realizes it tells the time.

We’ve featured [David’s] work before too, in the form of the handy ESP8266 breadboard socket. Video after the break.

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Ikea Clock Gets Wanderlust

February 6, 2023 by Al Williams 29 Comments

We always enjoy unique clocks, and a recent 3D print from [David Kingsman] caught our eye. It converts an Ikea clock into a very unusual-looking “wandering hour” clock that uses a Geneva drive to show a very dynamic view of the current time. The concept is based on an earlier wandering clock, but [David] utilized a different mechanism.

To read the clock, you note which hour numeral is in range of the “minute arc” and read the time directly. So if the 12 hour is over the 20-minute mark, the time is 12:20. Besides the clock, you need a fair number of printed parts, although they all look like relatively simple prints. You’ll also need 13 bearings and some metric hardware. A piece of cardboard used for the face rounds out the build.

Modifying the clock is more than just taking it apart. There is a template file to print, and you’ll need to align it and drill holes as indicated.

If you haven’t seen a Geneva drive before, it translates a continuous rotation into intermittent rotation. This isn’t the first clock we’ve seen use this kind of drive, although the last one we saw represented time differently. If you want something even more mechanical, try a chain-driven clock.

Sundial Collection Is 2D Printed

February 5, 2023 by Al Williams 3 Comments

We see a lot of clocks, and many of the better ones have some 3D printed elements to them. But [Carl Sabanski] shows us his kits for making sundials for either hemisphere using a conventional printer (you know, one that puts ink on paper), some styrofoam, and possibly some other materials like wire coat hangers, threaded rods, thumbtacks, glue, and different papers like transparencies or card stock.

In all, there are 21 different kinds of sundials. Some are pretty standard-looking fare, but there are others, like the pinwheel equatorial sundial or the cycloid polar sundial, which might be surprising. One even uses a CD as a kind of indicator.

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