Hackaday Prize Entries: Inventing New Logic Families

One of the favorite pastimes of electronics hobbyists is clock making. Clocks are a simple enough concept with a well-defined goal, but it’s the implementation that matters. If you want to build a clock powered only by tubes and mains voltage, that’s a great skill tester. A relay-based timepiece is equally cool, and everyone should build a Nixie tube clock once in their lives.

For [Ted]’s Hackaday Prize entry, he’s building a clock. Usually, this would be little cause for celebration, but this is not like any clock you’ve ever seen. [Ted] is building this clock using only diodes, and he’s inventing new logic families to do it.

Using diodes as logic elements has been around since the first computers, but these computers had a few transistors thrown in. While it is possible to make AND and OR gates using only diodes, a universal logic gate – NANDs and NORs – are impossible. For the computers of the 1950s, that means tubes or transistors and DTL logic.

For the past few years, [Ted] has been working on a diode-only logic family, and it appears he’s solved the problem. The new logic family includes a NOR gate constructed using only diodes, resistors, and inductors. The key design feature of these gates is a single diode to switch an RF power supply on and off. It relies on an undocumented property of the diodes, but it does work.

Although [Ted] can create a NOR gate without transistors — a feat never before documented in the history of electronics — that doesn’t mean this is a useful alternative to transistor logic. The fan-out of the gates is terrible, the clock uses about 60 Watts, and the gates require an AC power supply. While it is theoretically possible to build a computer out of these gates, it’s doubtful if anyone has the patience to do so. It’s more of a curiosity, but it is a demonstration of one of the most mind-bending projects we’ve ever seen.

You can check out a video of the diode clock below.

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Gutting And Rebuilding A Classic Watch

No, that watch isn’t broken. In fact, it’s better.

[Lukas] got so used to his binary-readout ez430 Chronos watch that when the strap disintegrated he had to build his own to replace it. But most DIY wristwatches are so clunky. [Lukas] wanted something refined, something small, and something timeless. So he shoe-horned some modern components, including an MSP430, into a Casio F-91W watch.

The result is a watch that tells time in binary, has a built-in compass, and with some more work will be updatable through an IR receiver that he also managed to fit in there somehow. Now he has the watch that Casio would make today, if fashion had stayed stuck firmly in the early 1990s. (Or not. Apparently, Casio still makes and sells the F-91W. Who knew?)

Anyway, back to an epic and pointless hack. Have a look at the tiny, tiny board that [Lukas] made. Marvel in the fact that he drove the original LCD screen. Dig the custom Kicad parts that match the watch’s originals. To get an accurate fit for the case, [Lukas] desoldered the piezo buzzer contact and put the board onto a scanner, which is a great trick when you need to get accurate dimensions. It’s all there, and well-documented, in his GitHub, linked above.

All in all, it’s an insane hack, but we love the aesthetics of the result. And besides, sometimes the hacking is its own reward.

Electronic Driver Replaces Master Clock

In these days of cheap microprocessors and easy access to accurate timing through NTP or from the likes of MSF, WWVB, or DCF77, it’s no problem to ensure that any number of clocks keep the same time. In a simpler age though they didn’t have these tools at their disposal, so when a large organisation wished to ensure that all its parts ran on the same time they used an electromechanical solution. A master clock of as high a quality as the clockmakers of the day could build was fitted with a microswitch. The switch would send pulses to slave clocks which had a solenoid where a traditional clock has a pendulum. Thus every clock in the system lost or gained time at the same rate.

[Edo Lelic] has a rather nice Iskra slave clock, but unfortunately not the master that once drove it. Undeterred by this setback, he’s created an electronic driver board that generates the required 100mS pulses. His weapon of choice was a PIC microcontroller and an H-bridge driver to deliver their required voltage and polarity. The clock was designed to accept 100V pulses, but since it has an internal series resistor he determined that the solenoid was happy with a mere 24V. Source code is available, downloadable at the bottom of the linked article.

These clocks are an unseen piece of technology that is disappearing without our noticing. If you find one – or even better if you find a master clock – you’ll find it to be a very high quality timepiece indeed. A master clock would be well worth snapping up. At least now you won’t have to look too far for a driver for it.

We haven’t seen too many projects like this here at Hackaday. Save for a rather nice digital master clock build, it’s uncharted territory. Almost justification for a Retrotechtacular piece, perhaps.

Thanks [Muris Pučić] for the tip.

Unary Clock for the Binary-Challenged

If binary clocks have you confused by all the math required to figure out what time it is, we have the solution for you: a unary clock. After all, what’s simpler than summing up powers of two? Powers of one! To figure out the time, you start with the ones digit. If it’s on, you add one to the total. Then move on to the next digit. Since 12 equals one, you add another one if it’s lit. Then on to the third LED. 13 = 1, so if it’s lit, you add another one, and so on.

OK, we’re messing around. Calling this a “unary” clock is ridiculous. When it’s seven o’clock, there are seven LEDs lit. Nice and easy to read. Sixty minute LEDs is silly, so here each minute LED stands for five minutes. Good enough.

What we really like about this clock is the build. It’s intended as educational for school kids, so it has to be simple to build and easy to personalize. Building the body out of Lego bricks fits the specs nicely. Transparent Lego bricks are used to give the white LEDs some color. That was too bright, so [Shrimping It] added paper cutouts from a hole punch as diffusers.

Clock builds are a great intro to electronics because they offer so many possibilities. Whether you want to go geary, use the clock as an excuse to try out fabrication techniques, or showcase a neat display technology, your imagination has a lot of room to wander. Show us yours?

Hackaday Prize Entry: ForEx Display is A Well Executed Hack

[Stefan] works in a place where knowing the exact state of the foreign-exchange market is important to the money making schemes of the operation. Checking an app or a website was too slow and broke him out of his workflow. OS desktop widgets have more or less departed this earth for the moment. The only solution then, was to build a widget for his actual desk.

The brains of the device is a ESP8266 board, some peripherals and a small backlit TFT display. The device can run off battery or from a wall wart. [Stefan] even added some nice features not typically found in hacks like this, such as a photocell that detects the light level and dims the screen accordingly.

The software uses an interesting approach to get the latest times and timezones. Rather than use a chart or service made for the task, he uses an open weather API to do the task. Pretty clever.

The case is 3D printed and sanded. To get the nice finish shown in the picture [Stefan] spray-painted the case afterwards. All put together the device looks great and gives him the desktop widget he desired.

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Fallout Inspired Cellphone Wristwatch

[Mr. Volt] mentions that some of the commenters on his videos believed that he shouldn’t be making large, retro computer themed communicator watches. He believes they are wrong, naturally we are compelled to agree with him.

thrumbzIn his latest build he has produced a rather well-built and large cell-phone watch. After the untimely death of an Apple II cellphone watch, he decided to up his game and make one that could take more of a beating. The case is 3D printed, which is hard to believe given the good finish. He must have spent a long time sanding the prints. Some wood veneer for looks and aluminum panels for strength complete the assembly.

The electronics are a Teensy and a GSM module. It looks like he places calls by calling the operator since the wrist communicator only has four inputs: a red button, a blue button, and a momentary switch rotary encoder.

The communicator appears to work really smoothly, and it would certainly draw attention to him were he to wear it anywhere other than the Wasteland. Video after the break.

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A Rubidium Reference for Discrete Component Clocks

Sometimes you open a freshly created Hackaday.io project and discover more than you expect. A moment of idle curiosity turns into a lengthy read involving several projects you wonder how you managed to miss the first time around. So it was this morning, with [Yann Guidon]’s documentation of his eBay-purchased rubidium frequency standard. In itself an interesting write-up, with details of reverse engineering the various different internal clock signals to derive more than just the standard 1-second pulses, and touching on the thermal issues affecting frequency lock.

Transistors were EXCITING back then!
Transistors were EXCITING back then!

It is when you look at his intended use for the standard that you’ll see the reason for the lengthy read. He has a couple of discrete component clock projects on the go. His first, a low-powered MOSFET design, promises to break the mold of boring silicon bipolar transistors with hefty power consumption. It is his second, a design based on germanium transistors and associated vintage components, that really stands apart. Not a Nixie tube in sight, but do browse the project logs for a fascinating descent into the world of sourcing vintage semiconductors in 2016.

Neither clock project is finished, but both show significant progress and they’ll certainly keep time now that they’ll be locked to a rubidium standard. Take a look, and keep an eye on progress, we’re sure there will be more to come.

We’ve featured a couple of rubidium standards here in the past. This rather impressive clock has one, and here’s one assembled into a piece of bench equipment. They’re readily available as surplus items for the curious constructor, we’re sure that more will feature here in the future.