Magnet Clock Makes Field Lines Visible

December 14, 2022 by Robin Kearey 1 Comment

The traditional method for visualizing magnetic fields, which your science teacher probably demonstrated at some point, is to sprinkle some iron filings onto a piece of paper and hold it over a magnet. It’s a bit of a messy process though, and nowadays there’s a more modern method available in the form of magnetic viewing films. These work thanks to tiny nickel particles suspended in an oily medium, and come in very handy if you want to examine, say, the magnetic field pattern of a DC electric motor. [Moritz v. Sivers] had another idea for this magic material however, and used it to make a Magnet Viewing Clock.

The clock’s front panel looks very similar to a large monochrome LCD, but is actually a big slab of magnetic viewing film. Four disks are mounted behind it, each carrying number-shaped magnetic stickers that are cleverly hidden from view. An Arduino Uno keeps track of time through a real-time clock and operates four stepper motors that rotate the number wheels. When they move into position, their magnetic stickers become visible through the film and you can read the time.

The clock’s mechanical parts are 3D printed, while the digits were cut from a sheet of sticky magnetic foil using a vinyl cutter. If you’d like to try making something similar you’re in luck: [Moritz] made the design files and the Arduino sketch available on his GitHub page. Magnetic viewing films are pretty neat things to play with anyway, and can even be used to read hidden messages.

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HUD-Like Clock Is A Transparent Time Display

December 14, 2022 by Lewin Day 13 Comments

While we have all types of displays these days, there’s something special about those that appear to float in the air. This HUD clock from [Kiwi Bushwalker] is one such example.

The build relies on four 8×8 LED matrixes to display the four digits that make up the time, run by the MAX7219 driver chip. However, the LEDs aren’t viewed directly — that would be too simple. Instead, the matrixes shoot their light up at an angle towards a tilted piece of clear acrylic. This creates a “heads-up display” look where the numbers appear to float in the air. The clock gets accurate time from an NTP time server over WiFi, thanks to the ESP32 microcontroller that runs the show.

It’s a straightforward clock build in many ways, but we particularly like the use of the heads-up display technique. It’s almost surprising we don’t see these projects more often, for things like car dashboard displays or targeting womp rats in a T-16 landspeeder. If you’ve been whipping up your own HUD projects, don’t hesitate to notify the tipsline!

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An alarm clock with a Nixie tube display

Retro Alarm Clock With Nixies Is Thoroughly Modern Inside

December 10, 2022 by Robin Kearey 12 Comments

We feature a lot of clocks here at Hackaday, but alarm clocks seem to be less popular for some reason. Maybe that’s because no-one enjoys being woken up in the morning, or simply because everyone uses their smartphone for that purpose already. In any case, we’re delighted to bring you [Manuel Tosone]’s beautiful Nixie tube alarm clock that cleverly combines modern and classic technologies in a single package.

The clock and alarm functionalities are implemented by a PIC24 microcontroller on a custom mainboard. It keeps track of time through its real-time clock with battery backup, and plays a song from an SD card when it’s time to wake up. A 2 x 3 W class D audio amplifier plus a pair of stereo speakers should be able to wake even the heaviest sleepers.

Of course, the real party piece is the clock’s display: four IN-4 Nixie tubes show the time, with neon tubes indicating the day of the week. The 180 V needed for the Nixies is generated by an MC34063A-based boost converter, which also powers the neon tubes.

Instead of using the standard current-limiting resistor for each Nixie tube, [Manuel] designed an array of transistor-based current sources: this enables linear control of the tubes’ brightness, and should keep the amount of light constant even as the tubes age. The individual segments are switched by SN75468 Darlington arrays, with no need for those hard-to-find SN74141 drivers.

The mainboard and the display are housed inside a 3D-printed case that mimics the style of 1980s digital alarm clocks, but with a nice 1970s twist courtesy of those Nixie tubes. [Manuel]’s GitHub page has all the schematics as well as extensive documentation describing the circuit’s operation — an excellent resource if you’re planning to build a Nixie project yourself. If Nixies aren’t your thing, you can also make an alarm clock with a VFD tube, or even roll your own luminous analog dial.

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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 Robin Kearey 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 Lewin Day 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 Kristina Panos 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 Tom Nardi 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.