Mini-VFD Clock Floats The Display Above It All

September 26, 2019 by Dan Maloney 14 Comments

As [sjm4306] says, “You can never have too many clocks based on obsolete display technologies.” We couldn’t agree more, and this single-tube VFD clock is one we haven’t seen before.

The vacuum-fluorescent display that [sjm4306] chose to base this clock on is the IV-21, an eight-digit seven-segment display on the smallish side. The tube is Russian surplus from the ’80s, as all such displays seem to be. The main PCB sports an ATMega328, a boost converter to provide the high voltage needed to run the VFD, a real-time clock, and the driver chip for the tube segments. The tube itself lives on a clever riser card that elevates the display above the main PCB and puts it at the proper angle for reading. [sjm4306] designed it to be modular; should you want to user a bigger VFD you need only make a new riser PCB. Figuring out the proper way to space the through-holes in Eagle proved elusive, but he hacked a solution using a spreadsheet to handle the trigonometry and spit out Cartesian coordinates for each hole. Pretty neat. The video below shows the clock assembly and a test.

We really like the look of this clock for some reason – perhaps it’s the quirky nature of the VFD, or the soft teal glow of the digits. We’ve featured plenty of clocks with odd displays before: VFDs large and small, faux-NIMO, de-encapsulated LED “filaments”, and lots and lots of Nixies.

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100 Year Old Atomic Clock

September 25, 2019 by Gregory L. Charvat 33 Comments

Precision time is ubiquitous today thanks to GPS and WWVB. Even your Macbook or smartphone displays time which is synchronized to the NIST-F1 clock, a cesium fountain atomic clock (aka the ‘Atomic Clock’) that is part of a global consortium of atomic clocks known as Coordinated Universal Time (UTC). Without precise timing there would be train collisions, markets would tumble, schools would not start on time, and planes would fall out of the sky.

But how was precision timing achieved in the 19th century during the era of steam, brass, and solenoids? One of the first systems of precision timing kept trains running safely and on time, rang the bells at school, and kept markets trading by using a special clock designed by the Self Winding Clock Company. Through measurements of celestial objects by the US Naval Observatory, and time synchronization pulses broadcast by the Western Union telegraph network, this system synchronized time across the United States in an era where the speed of our train system was out-pacing by the precision of our clocks.

Those clocks were designed so well that many of them are still around and functioning. One of these 100-year-old self-winding clocks made its way onto my workbench. I did what any curious hacker would do, figured out how the synchronization worked and connected it to a clock source with atomic precision. Let’s take a look!

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Can You Read Me The Time?

September 21, 2019 by Sharon Lin 11 Comments

If you’re like the average clock user, you’ve probably gotten annoyed at reading analog clocks before. Typically, the solution is just to use a digital timepiece, but [sjm4306] has opted to make a small word clock that you can carry with you wherever you go to remind you of the time in the English language.

Unlike a similar project made by [Gordan Williams], which uses an 8 x 8 LED matrix with an inkjet printed overlay, this small word clock uses a 3D-printed light box to achieve its letter matrix. In fact, they were inspired by all of the existing DIY word clock designs using anything from off-the-shelf LED arrays, transparency masks and WS2812s.

The design uses a home-brewed PCB design that runs off 5 V via USB. The design places the letters on the top stop and restricts layers to keep the solder mask and copper from obstructing the light. The bottom side uses the same design principle with a square shape that overlaps the letter. In order to block light between adjacent letters, the 3D-printed light box comes into play.

One design challenge for the letter matrix was fitting all possible minutes into the array. Rather than making a larger array of letters, [sjm4306] had the clock describe the time down to five-minute intervals then add asterisks for the full time. It’s a pretty understandable solution for keeping the design simple, and the letters all fit onto the design so well!

Using a pin map assigned to the I/O for the rows and columns of the array, the software toggles the states of the pins as a switch statement. For scanning the matrix, the software uses an interrupt that draws the current column of LEDs and updates the display image before incrementing to the next column. By skipping or not skipping cycles, this allows the display to look brighter or dimmer.

The time tracking is fairly simple, using a DS1302 serial real time clock chip – it even charges a super capacitor to keep time after power is removed!

To tackle the light scattered internally in the PCB’s FR4 material, a separator is used to contain the light. As a low-cost solution, while there is still some amount of light diffused, it’s definitely better than without the separator.

Almost all of the files used for building the small word clock are available on [sjm4306]’s project page, including the software and design files. It hopefully won’t be too long before we start seeing more of these low-cost word clock designs!

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Keeping Clocks On Time, The Swiss Way

September 17, 2019 by Dan Maloney 31 Comments

Could there be a worse fate for a guy with a Swiss accent than to be subjected to a clock that’s seconds or even – horrors! – minutes off the correct time? Indeed not, which is why [The Guy With the Swiss Accent] went to great lengths to keep his IKEA radio-controlled clock on track.

For those who haven’t seen any of [Andreas Spiess]’ YouTube videos, you’ll know that he pokes a bit of fun at Swiss stereotypes such as precision and punctuality. But really, having a clock that’s supposed to synchronize to one of the many longwave radio atomic clocks sprinkled around the globe and yet fails to do so is irksome to even the least chrono-obsessive personality. His IKEA clock is supposed to read signals from station DCF77 in Germany, but even the sensitive receivers in such clocks can be defeated by subterranean locales such as [Andreas]’ shop. His solution was to provide a local version of DCF77 using a Raspberry Pi and code that sends modulated time signals to a GPIO pin. The pin is connected to a ferrite rod antenna, which of course means that the Pi is being turned into a radio transmitter and hence is probably violating the law. But as [Andreas] points out, if the power is kept low enough, the emissions will only ever be received by nearby clocks.

With his clock now safely synced to an NTP server via the tiny radio station, [Andreas] can get back to work on his other projects, such as work-hardening copper wire for antennas with a Harley, or a nuclear apocalypse-Tweeting Geiger counter.

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Impractical Clock Uses Tuning Fork

August 29, 2019 by Al Williams 30 Comments

Clock projects are so common that they are almost a cliche. After all, microcontrollers have some clock source and are good at counting, so it stands to reason that a clock is an obvious project. [WilkoL’s] clock though has a most unusual clock source: a 440 Hz tuning fork.

A cheap plastic dome really shows off the fork and contributes to this good-looking build. An ATTiny13 divides the input frequency down, handles the display, and obeys the adjustment buttons. It does require a little metalworking, as the tuning fork needed filing and threading, although we bet you could figure out other ways to mount it.

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This Wristwatch Is A Free Form Work Of Art

July 27, 2019 by Jenny List 4 Comments

Free-form circuitry built as open wire sculpture can produce beautiful pieces of electronics, but it does not always lend itself to situations in which it might be placed under physical stress. Thus the sight of [Mile]’s free-form wristwatch is something of a surprise, as a wristwatch cam be exposed to significant mechanical stress in its everyday use.

A wire Wrencher graces thewe underside. — A wire Wrencher graces the underside.

The electronic side of this watch is hardly unusual, the familiar ATmega328-AU low-power microcontroller drives a tiny OLED display. Mechanically though it is a different story, as the outline of a wristwatch shell is traced in copper wire with a very neat rendition of a Wrencher in its base, and a glass lens is installed over the screen to take the place of a watch glass. A strap completes the wristwatch, which can then be worn like any other. Power comes from a small 110 mAh lithium-polymer cell, which it is claimed gives between 6 and 7 hours of on time and over a month of standby with moderate use.

Unfortunately there does not seem to be much detail about the software in this project, but since ATmega328 clocks and watches are ten a penny we don’t think that’s a problem. The key feature is that free-form construction, and for that we like it a lot.

Nixiewatch Looks Stylish In Aluminium

July 23, 2019 by Lewin Day 10 Comments

Nixie tubes are a perennial favorite, with their burnt orange glow bringing a smile to the face of even the most jaded maker. Due to their power requirements they’re usually seen in desktop clocks, but [RemcoK3] decided to whip up a Nixiewatch, with stylish results.

Packing twin Nixie tubes, the watch displays hours first, then minutes. An accelerometer is fitted, switching the tubes on when the user checks the watch. There’s also Bluetooth and WiFi connectivity, which can be used to set the time as well as check the remaining battery life. Standby time is estimated to be 350 hours, thanks to a low-power microcontroller and keeping the tubes off most of the time.

The presentation is where this watch really shines, sporting as it does an RGB LED for backlighting and an attractive aluminium case. The design is simple, helping to highlight the industrial beauty of the Nixie tubes themselves. The housing was first mocked up with 3D printed parts, before the final piece was CNC milled. [RemcoK3] is contemplating anodizing the watch, but we think that the brushed aluminium already looks perfect.

If you’ve grown tired of the Nixie aesthetic, fear not – numitron watches are also a thing!