clock

592 Articles

Parts Shortage Forces Creativity For This Recursive Clock Of Clocks

July 25, 2021 by 9 Comments

We’ve been seeing a lot of metaclocks lately — a digital clock whose display is formed by the sweeping hands of an array of individual analog clocks. They can look fantastic, and we’ve certainly seen some great examples.

But in this time of supply pinches, it’s not always possible to gather the parts one needs for a full-scale build. Happily, that didn’t stop [Erich Styger] from executing this circular multi-metaclock with only thirteen of his custom dual-shaft stepper analog movements. Normally, his clocks use double that number of movements, which he arranges in a matrix so that the hands can be positioned to form virtual seven-segment displays. By arranging the movements in a circle, the light-pipe hands can mimic an analog clock face, or perform any of [Erich]’s signature “intermezzo” animations, each of which is graceful and engaging to watch. Check out a little of what this charmingly recursive clock has to offer in the video below.

[Erich] could easily have gotten stuck on the original design — he’s been at this metaclock game for a while, after all. The fact that the reduced part count forced him to get creative on the display is the best part of this build, at least to us.

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Precise Sundial Tells Time To The Minute

July 21, 2021 by 16 Comments

We’re always a fan of an interesting or unique clock build around here, which often use intricate pieces of technology to keep time such as weights and gears, crystal oscillators, or even a global network of satellites in the case of GPS. While these are all interesting methods of timekeeping, the original method of tracking the sun is often forgotten. With this clock, the sun is the main method of keeping track of time, but unlike traditional sundials it has a number of advancements that let it keep surprisingly accurate time. (Google Translate from German)

While most sundials can only show hours, this one from [leon andré], a retired physicist, has a method for displaying minutes as well. It uses pinholes instead of shadows to keep track of the position of the sun, with the pinhole casting a bright spot of sunlight onto a diagram below. The diagram keeps track of the minutes, and consists of curved lines which help account for the sun’s changing path throughout a typical year. The dial keeps track of local solar time, as any sundial would, but by rotating it along its vertical axis it can be calibrated for the timezone that it’s in regardless of its position.

As far as clock builds go, one that is completely passive like this semi-digital sundial is fairly unique, especially for its accuracy. And, when set to local solar time, it will be the most reliable method of keeping time long-term than possibly any other clock we’ve seen before, as long as it’s not too cloudy outside. On the other hand, it is possible to augment a sundial with some modern technology as well.

Thanks to [Adrian] for the tip!

A Perfect Clock For Any Hacker’s Ohm

July 15, 2021 by 29 Comments

The vast majority of us are satisfied with a standard, base ten display for representing time. Fewer of us like to be a bit old-fashioned and use a dial with a couple of hands that indicate the time, modulo twelve. And an even smaller minority, with a true love for the esoteric, are a fan of binary readouts. Well, there’s a new time-telling game in town, and as far as we’re concerned it’s one of the best ones yet: resistor color codes.

The Ohm Clock is, as you may have guessed, a giant model of a resistor that uses its color bands to represent time.  Each of the four bands represents a digit in the standard HH:MM representation of time, and for anybody well-versed in resistor codes this is sure to be a breeze to read. The clock itself was designed by [John Bradnam]. It’s body is 3D printed, with RGB LEDs to brightly illuminate each segment. The whole thing is controlled by an old favorite – an ATtiny, supported by a Real Time Clock (RTC) chip for accurate timekeeping.

You can set the time in the traditional fashion using buttons, or — and here’s the brilliant part — you can use a resistor. Yup, that’s right. Connecting a 220 Ohm resistor across two terminals on the clock will set the time to 2:20. Genius.

When you come across an art as old as timekeeping, it’s easy to assume that everything’s already been done. We have sundials, hourglasses, analog clocks, digital watches, those cool clocks that use words instead of numbers, the list goes on. That’s why it’s so exciting to see a new (and fun!) idea like this one emerge.

Astronomical Clock Uses Your Spare Clock Motors

July 10, 2021 by 1 Comment

We’ll admit we are suckers for clock projects, and the more unusual, the better. We liked the look of [Peter Balch’s] astronomical clock, especially since it was handcrafted and was a relatively simple mechanism. [Peter] admits that it looks like an astronomical clock, but it isn’t the same as a complex instrument from medieval times. Instead, it uses several standard clock motors modified.

We didn’t quite follow some of the explanations for the rotation of the different elements, but the animated GIF cleared it all up. The inner and outer discs are geared at a 6:5 ratio. It takes 2 hours for the inner disc to make one rotation, meaning that every 12 hours the two discs will be back to where they began relative to one another.

Modifying the motors is fine work, requiring a good bit of disassembly and some glue. The electronics that make it tick are quite interesting. To drive the motors, a very specific pulse train is needed, but you also want to conserve battery as much as possible. A simple oscillator with a hex inverter drew more power than desired and an Arduino, even more so. A PIC12F629, though, could sleep a lot and do the job for a very low current consumption. The final clock should run a year on two AA cells.

A Custom Clock With LED Filament Hands

June 25, 2021 by 13 Comments

LEDs have become so ubiquitous in our projects that just hearing that term probably conjures images of tiny illuminated domes in an array of single-spectrum colors. It’s easy to forget that these efficient sources of light come in a variety of form factors, including the retro-tacular filaments that [bitborked] used to make his beautiful analog LED wall clock.

Aside from its aesthetics, this timepiece features some great design. A custom PCB acts as a hub for all the LED filament spokes. The onboard brains come in the form of an ESP32, which means it can keep extremely accurate time via NTP. WS2811 LED controllers, which we’re so accustomed to seeing alongside RGB LEDs that they almost feel strange to see here, provide the 12 volts required for each filament and make individual addressing a breeze.

[bitborked] takes advantage of that addressability to display other animations in addition to the standard clock face. They also plan to implement MQTT for eventual alerts from other home automation devices. When it comes to just telling time, you can discern the individual “hands” by differences in their brightness, which sadly does not show up as well in video as it does in real life.

We would certainly be happy to have this clock on our walls, and we hope to eventually see more of its PCB designs. In the meantime, though, we can drool over a more digital take on the LED filament clock. Although, filaments are certainly not required to make a beautiful LED timekeeper.

Using Heaters To Display Time

June 17, 2021 by 9 Comments

We’re always fans of interesting clock builds around here, whether it’s a word clock, marble clock, or in this case a clock using a unique display method. Of course, since this is a build by Hackaday’s own [Moritz v. Sivers] the display that was chosen for this build was a custom thermochromic display. These displays use heat-sensitive material to change color, and his latest build leverages that into one of the more colorful clock builds we’ve seen.

The clock’s display is built around a piece of thermochromic film encased in clear acrylic. The way the film operates is based on an LCD display, but using heat to display the segments. For this build, as opposed to his previous builds using larger displays, he needed to refine the method he used for generating the heat required for the color change. For that he swapped out the Peltier devices for surface mount resistors and completely redesigned the drivers and the PCBs around this new method.

Of course, the actual clock mechanism is worth a mention as well. The device uses an ESP8266 board to handle the operation of the clock, and it is able to use its wireless capabilities to get the current time via NTP. All of the files needed to recreate this are available on the project page as well, including code, CAD files, and PCB layouts. It’s always good to have an interesting clock around your home, but if you’re not a fan of electronic clocks like this we can recommend any number of mechanical clocks as well.

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Historical Hackers: Ctesibius Tells Time

June 9, 2021 by 11 Comments

People are obsessed with the time and the weather. We’ve talked about the weather since we were all cave dwellers hunting with spears. But the time is a different matter. Sure, people always had the idea of the passage of time. The sun rising and setting gives a natural sense of days, but daylight and dark periods vary by the time of year and to get an accurate and linear representation of time turns out to be rather difficult. That is unless you are a Greek engineer living in Alexandria around 250 BC.

Legend has it that and engineer working in his father’s barbershop led him to discover not only the first working clock, but also the pipe organ, launching the field of pneumatics in the process. That engineer was named Ctesibius and while his story is mostly forgotten, it shows he has a place as a historical hacker.

You might think there were timekeeping devices before 250 BC, and that’s sort of true. However, the devices before Ctesibius had many limitations. For example, a sundial can tell time, but only if the sun is shining. At night or during a storm it is worthless.

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