clock hacks

925 Articles

A dekatron-based clock with a GPS receiver and a plastic dinosaur on top

Dekatron Clock Tells The Time, Sans Semiconductors

December 5, 2022 by 19 Comments

Over the years, there have been several memory and display technologies that served a particular niche for a while, only to be replaced and forgotten when a more suitable technology came along. One of those was the dekatron: a combination memory and display tube that saw some use in the 1950s and ’60s but became obsolete soon after. Their retro design and combined memory/display functionality make them excellent components for today’s clock hackers however, as [grobinson6000] demonstrates in his Dekaclock project.

A dekatron tube is basically a neon tube with ten cathodes arranged in a circle. Only one of them is illuminated at any time, and you can make the tube jump to the next cathode by applying pulses to its pins. The Dekaclock uses the 50 Hz mains frequency to generate 20 ms pulses in one tube; when it reaches 100 ms, it triggers the next tube that counts hundreds of ms, which triggers another one that counts seconds, and so on with minutes and hours.

The Dekaclock uses no semiconductors at all: the entire system is built from glass tubes and passive components. However, [grobinson6000] also built an auxiliary system, full of semiconductors, that makes the clock a bit easier to use. It sits on top of the Dekaclock and automatically sets the correct time using a GPS receiver. It also keeps track of the time displayed by the dekatrons, and tells you how far they have drifted from their initial setting.

Both systems are housed in sleek wooden cases that perfectly fit the tubes’ retro aesthetic. [grobinson6000] was inspired to make the Dekaclock after watching another dekatron clock we featured earlier, and designed the GPS receiver to work alongside it. Dekatrons are surprisingly versatile devices: you can use them to make anything from internet speed gauges to kitchen timers.

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A Timepiece Straight Out Of Back To The Future

December 2, 2022 by 20 Comments

[Stephen Holdaway] needed a desk clock, and decided to whip something up from scratch. The result is a beautiful tribute to the DeLorean’s time circuits from legendary 1985 film Back to the Future.

We say it’s a tribute rather than an exact replica, as it only implements the “present time” section of the time circuits. However, for those of us without time machines, that’s more than enough. In any case, the build is a very faithful recreation. It uses a lovely sheet metal enclosure complete with era-appropriate sticky labels.

Naturally, the numerals are all shown on green segment displays, though [Stephen] used 16-segment devices instead of the more typical 7-segment parts. What really helps add to the look is the shaded acrylic windows, which adds a very nice effect.

It’s a nice tribute piece that any fan would instantly recognize. We’ve seen some other great builds, too, like this replica of the RC controller that first gets the DeLorean up to 88 mph. If you’ve been whipping up your own neat prop project, don’t hesitate to hit us up on the tipsline!

Circular Binary Clock Uses The Power To Tell Time

November 25, 2022 by 5 Comments

Should a clock be round? Depends on the style of clock, we suppose. After all, we wouldn’t expect to see a digital clock with a round readout just for fun. But a binary clock — that’s another animal altogether. Whereas [JohnThinger] made just a few weeks back a linear binary clock using an RGB LED strip and an ATtiny, he decided it would look much better in the round.

Before you go decrying the fact that there are numbers other than 1 and 0 on the thing, those are simply the power of two by which one must multiply to get the time. And naturally, it’s done in three phases, with the yellow-green numbers representing the seconds, the pink-red representing minutes, and the blue standing for the current hour. No, the point is not to make life easier. But it’s a good-looking clock, no?

Just as before, an ATtiny85 is the brain, with an RTC chip and an oscillator to keep time. But now, the display involves negative space 3D-printed numbers and an RGB LED ring. Be sure to check it out after the break.

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ESP32 LED Eyes Help Keep Toddler In Bed

November 19, 2022 by 14 Comments

We’ve seen a lot of custom clocks here at Hackaday, many of which have pushed the traditional definition of the timepiece to its absolute limit. But for all their wild designs, most of them do have something in common: they assume you can actually read a clock and understand the concept of time. But what if you’re developing a clock for a toddler who’s only just coming to terms with such heady ideas?

The answer, at least for [Riley Parish] is a set of 3D printed eyes that are illuminated with either yellow or green LEDs depending on whether or not it’s time to get out of bed. More than just the color of the light, the eye design (which is embedded into the rear of the front panel) switches between wide-open and tightly shut depending on the time of day.

Internally the device is very simple, with the 5 mm LEDs and their associated resistors connected directly to the digital out pins on an ESP32 development board. While the dual-core microcontroller is admittedly pretty overkill for flipping some LEDs every 12 hours or so, the firmware does at least pull the current time from NTP — plus the powerful MCU offers plenty of room to grow. A web front-end to configure the device or check its current status would only be a few more lines of code.

As it so happens, this isn’t the first toddler timepiece to grace these pages. Perhaps unsurprisingly, those previous examples also used changing color to help indicate the passage of time.

Faceless Clock Makes You Think Twice About How It Works

November 18, 2022 by 23 Comments

We love projects that make you do a double-take when you first see them. It’s always fun to think you see one thing, but then slowly realize everything is not quite what you expected. And this faceless analog clock is very much one of those projects.

When we first saw [Shinsaku Hiura]’s “Hollow Clock 4,” we assumed the trick to making it look like the hands were floating in space would rely on the judicious use of clear acrylic. But no, this clock is truly faceless — you could easily stick a finger from front to back. The illusion is achieved by connecting the minute hand to the rim of the clock, and rotating the whole outer circumference through a compact 3D printed gear train. It’s a very clever mechanism, and it’s clear that it took a lot of work to optimize everything so that the whole look of the clock is sleek and modern.

But what about the hour hand? That’s just connected to the end of the minute hand at the center of the clock’s virtual face, so how does that work? As it is with most things that appear to be magical, the answer is magnets. The outer rim of the clock actually has another ring, this one containing a pair of neodymium magnets. They attract another magnet located in the very end of the hour hand, dragging it along as the hour ring rotates. The video below shows off the secrets, and it gives you some idea of how much work went into this clock.

We’re used to seeing unique and fun timepieces and other gadgets from [Shinsaku Hiura] — this up-flipping clock comes to mind, as does this custom RPN calculator — but this project is clearly a step beyond.

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Creating Your Alarm On The Fly

November 5, 2022 by 4 Comments

We suspect that most of us who use an alarm clock have our particular sound memorized. Common choices are annoying beeping, energetic marimbas, or what used to be your favorite song (which you have now come to despise). [Adam Kumpf] wanted a more pleasant alarm clock and came up with WakeSlow, an alarm clock audio stream, which is a spiritual successor to an earlier project he did called Warmly.

Some might say, “an audio stream? You could create an acceptable alarm tone generator with a 555 and a 2N2222”. The idea behind WakeSlow is to use your existing internet-connected alarm clock that can play an audio stream. You generate a URL using WakeSlow, and it plays the alarm. A custom URL is helpful since it incorporates weather data, letting you know if it’s going to rain, blowing wind, or be sunny that day. It mixes CC0 audio to form the stream, and includes a 5-minute fade to wake you up gradually. After five minutes, it’s jazz time, and it plays a sample of some CC0 jazz.

The code is super simple, and he makes it available on his website under a public domain/CC0 license. The simplicity offers something powerful, making it exactly how you like it. You could incorporate holiday information, a text-to-speech news announcer reading the news of what’s on your calendar that day, or anything you can dream of.

Hackers are generally particular about clocks, and alarm clocks fall under the same umbrella. WakeSlow allows you to skip the hardware part of making your customized alarm, but if you prefer to have the whole thing be custom, we have a few suggestions for alarms to look at.

Digital Hourglass Counts Down The Seconds

October 26, 2022 by 20 Comments

If someone asked you to build a digital hourglass, what would your design look like? [BitBlt_Korry] took on that challenge, creating a functional art piece that hits it right on the nose: an hourglass with a digital display. 

Iron filings fall between two pieces of plexiglass while ghostly numbers appear, counting down 30 seconds. Just as quickly as they appear, the numbers disappear – dropping down to the bottom of the enclosure. Each second is punctuated by what might be the loudest clock tick we’ve ever heard.

Of course, it’s not all magic. The hourglass is controlled by a Raspberry Pi Pico running code in MicroPython. The pico drives a series of transistors, which in turn are used to control 14 solenoids.  The solenoids serve double duty — first, they move pieces of flat “fridge magnet” material close enough to attract iron filings. Their second duty is of course provide a clock tick that will definitely get your attention.

Tilt sensors are the user input to the hourglass, letting the Pi Pico know which end is up when it’s time to start a new 30-second countdown.

[BitBlt_Korry] mentions that the hardest part of the project was setting the screws at the top and bottom of the hourglass to get the perfect uniform flow of iron filings. 

[BitBlt_Korry] calls his creation “「時場(じば)」”.  Google translates this to “Jiba”, which means “magnetic field”.  We’re not native speakers, but we’re guessing there is a double meaning there.

This isn’t the first time we’ve seen humble iron filings stand up and dance at our command. If iron dust is too dry a topic, we’ve got plenty of ferrofluid projects as well!

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