Nixie Gear Indicator Shines Bright

January 20, 2026 by 12 Comments

When you’re driving a car with a stickshift, it’s pretty easy to keep track of which gear you’re in. That can be a little bit more difficult on something like a motorcycle with a sequential shifter. [decogabry] built a neat gearshift indicator to solve this issue.

An ESP32 devboard is used as the brain of the build. It’s paired with an ELM327 dongle over Bluetooth, which is able to hook into the bike’s ODB diagnostic port to pick up data like engine RPM, wheel speed, and coolant temperature. The first two factors are combined in order to calculate the current gear, since the ratio between engine RPM and wheel speed is determined directly by the gear selection. The ESP32 then commands a Philips ZM1020 Nixie tube to display the gear, driving it via a small nest of MPSA42 transistors. A separate self-contained power supply module is used to take the bike’s 12 volt supply up to the 170 volts needed to run the tube. There is also a small four-digit display used to show status information, RPM, and engine temperature.

Notably,  [decogabry] made this build rather flexible, to suit any bike it might be installed upon. The gear ratios are not hard coded in software. Instead, there is a simple learning routine that runs the first time the system is powered up, which compares RPM and wheel speed during a steady-state ride and saves the ratios to flash.

We’ve featured projects before that used different techniques to achieve similar ends. It’s also interesting to speculate as to whether there’s a motorcycle vintage enough to suit a Nixie display while still having an ODB interface on board as standard. Meanwhile, if you’re cooking up your own neat automotive builds, don’t hesitate to drop us a line.

Nixie Tube Dashboard Is Period-Appropriate Hack To Vintage Volvo

December 24, 2025 by 10 Comments

There’s no accounting for taste, but it’s hard to argue with The Autopian when they declare that this Nixie tube dash by [David Forbes] is “the coolest speedometer of all time” — well, except to quibble that it’s also the coolest tachometer, temperature gauge, oil pressure indicator, and voltmeter. Yeah, the whole instrument cluster is on [David]’s Volvo PV544 is nixified, and we’re here for it.

He’s using a mixture of tubes here– the big ones in the middle are the speedo and tachometer, while the ovals on either side handle the rest. There’s a microcontroller on the front of the firewall that acts a bit like a modern engine control unit (ECU) — at least for the gauges; it sounds like the Volvo’s engine is stock, and that means carbureted for a car of that vintage.

The idea that this hack could have been done back in the 50s when the car was new just tickles us pink. Though you’d have probably needed enough valves to fill up the boot, as our British friends would say. Translate that to “enough vacuum tubes to fill the trunk” if you’re in one of the rebellious colonies.

We’ve featured [David]’s projects previously, in the form of his wearable video coat. But his best known work is arguably the Nixie Watch, famously the timepiece of choice for Steve Wozniak.

Thanks to [JohnU] for the tip!

All images by Griffin Riley via The Autopian

This Soviet-Style Clock Uses Homemade Nixie Tubes And Glowing Logic

August 31, 2025 by 11 Comments

The Neon glow of a Nixie tube makes for an attractive clock, but that’s not enough neon for some people. [Changliang Li] is apparently one of those people, because he’s using soviet-era cold-cathode tubes as the logic for his “Soviet-Era Style Clock”

Aside from the nixies for display, the key component you see working in this beautiful machine are the MTX-90 cold cathode thyratrons, which look rather like neon tubes in action. That’s because they essentially are, just with an extra trigger electrode (that this circuit doesn’t use). The neon tubes are combined into a loop counter, which translates the 50 Hz mains circuit in to seconds, minutes, and hours. The circuit is not original to this project, and indeed was once common to electronics books. The version used in this project is credited to [PA3FWM].

The Nixie tubes are new-made by [Sadudu] of iNixie labs, and we get a fascinating look in how they are made. (Tubemaking starts at around 1:37 in the video below.) It looks like a fiber laser is used to cut out glow elements for the tube, which is then encapsulated on a device which appears to be based around a lathe.

The cold-cathode tubes used as logic rely on ambient light or background radiation to start reliably, since the trigger electrode is left floating. In order to ensure reliable switching from the thyratrons, [Changliang Li] includes a surplus smoke detector source to ensure sufficient ionization. (The video seems to imply the MTX-90 was seeded with radioisotopes that have since decayed, but we could find no evidence for this claim. Comment if you know more.)

The end result is attractive and rather hypnotic. (Jump to 3:37 to see the clock in action.) If you want to know more about this sort of use for neon lamps (and the Soviet MTX-90) we featured a deeper dive a while back.

Thanks to [Changliang Li] for the incandescent tip. If one of your bright ideas has had a glow up into a project, don’t hesitate to share it on our tips line.

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2025 One Hertz Challenge: The Easy Way To Make A Nixie Tube Clock

August 7, 2025 by 3 Comments

Let’s say you want to build a Nixie clock. You could go out and find some tubes, source a good power supply design, start whipping up a PCB, and working on a custom enclosure. Or, you could skip all that, and just follow [Simon]’s example instead.

The trick to building a Nixie clock fast is quite simple — just get yourself a frequency counter that uses Nixie tubes for the display. [Simon] sourced a great example from American Machine and Foundry, also known as AMF, the company most commonly associated with America’s love of bowling.

The frequency counter does one thing, it counts the number of pulses in a second. Thus, if you squirt the right number of pulses to represent the time — say, 173118 pulses to represent 5:31 PM and 18 seconds — the frequency counter effectively becomes a clock. To achieve this, [Simon] just hooked an ESP32 up to the frequency counter and programmed it to get the current time from an NTP time server. It then spits out a certain number of pulses every second corresponding to the current time. The frequency counter displays the count… and there you have your Nixie clock!

It’s quick, dirty, and effective, and a sweet entry to our 2025 One Hertz Challenge. We’ve had some other great entries, too, like this nifty hexadecimal Unix clock, and even some non-horological projects, too!

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Close up of a DA14 nixie multimeter

The Nixie Tube Multimeter That Almost Made A Comeback

November 1, 2024 by 3 Comments

In a world of digital monotony, the Avo DA14 digital multimeter, with its vintage nixie tube charm, is a refreshing gem. Recently refurbished by [Thomas Scherrer], this multimeter video review is a blend of nostalgia and tech savvy. The DA14 not only has style, but substance — delivering resistance, current, and voltage measurements that make you wonder why more multimeters didn’t stick with this stylish glow.

As [Thomas] starts by powering up the DA14, we were instantly captivated as the Nixie tubes illuminate in their retro orange. With each twist of the dial, he demonstrates just how intuitive the multimeter is to operate, walking us viewers through each function while giving some extra love to its calibration process—a neat front-panel potentiometer that requires just a touch of finesse to get perfect readings.

But, as with all good tinkering tales, things go downhill when issues with analog inputs and the display pop up. A teardown reveals a beautifully complex inner assembly of transformers, rectifiers, and circuit boards, giving the DA14 its impressive yet fragile structure. When the critical defective display chip is found, hopes for a full repair dim. His story ends without a revival, but if you want to see a similar attempt that did get resurrected – albeit without those nixie digits – take a look at this LCD transplant we covered previously.

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Hands On With A Giant Nixie Tube

October 24, 2024 by 9 Comments

[Sam Battle] is no stranger to these pages, nor is his Museum is not Obsolete. The museum was recently gifted an enormous Nixie tube created by Dalibor Farný, a B-grade (well, faulty) unit that could not be used in any of their commissioned works but was perfectly fine for displaying in the museum’s retro display display. This thing is likely the largest Nixie tube still being manufactured; although we read that it’s probably not the largest ever made, it’s still awesome.

Every hacker should have their own museum.

It is fairly simple to use, like all Nixie tubes, provided you’re comfortable with relatively high DC voltages, albeit at a low current. They need a DC voltage because if you drive the thing with AC, both the selected cathode digit plate and the anode grid will glow, which is not what you need.

Anyway, [Sam] did what he does best, clamped the delicate tube in some 3D printed mounts and hooked up a driver made from stuff he scraped out of a bin in the workshop. Obviously, for someone deeply invested in ancient electromagnetic telephone equipment, a GPO (British General Post Office, now BT) uniselector was selected, manually advanced with an arcade-style push button via a relay. This relay also supplies the ~140 V for the common anode connection on the Nixie tube. The individual digit cathodes are grounded via the uniselector contacts. A typically ancient GPO-branded snubber capacitor prevents the relay contacts from arcing over and ruining the display unit. There isn’t much more to it, so if you’re in the Ramsgate, UK, area anytime soon, you can pop in and play with it for yourself.

Nixies are cool, we’ve covered Nixie projects for years, like this DIY project from ages ago. Bringing such things into the modern area is the current specialty of Dalibor Farný, with this nice video showing some of the workmanship involved. By the way — the eagle-eyed will have noticed that we covered this particular Nixie tube before, shown in the format of a large art installation. But it doesn’t hurt to get close up and play with it on the bench.\

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Symbolic Nixie Tubes Become Useful For Artistic Purposes

October 10, 2024 by 2 Comments

When it comes to Nixie tubes, the most common usage these days seems to be in clocks. That has people hunting for the numerical version of the tubes, which are usually paired with a couple of LEDs to make the colon in the middle of the clock. However, other Nixie tubes exist, like the IN-7, which has a whole bunch of neat symbols on it instead. [Joshua] decided to take these plentiful yet less-popular tubes and whip them up into a little art piece. 

The IN-7 is a tube normally paired with the numerical IN-4 tube in instrumentation, where it displays unit symbols relevant to the number being displayed. It can display omega, +, M, pi, m, A, -, V, K, and ~.

[Joshua]’s build is simple enough. It spells the word “MAKE” in Nixie tubes as a neat sign for a makerspace. It uses “M” for Mega, “A” for Amps, “K” for Kilo for the first three letters. The fourth letter, “e”, is achieved by turning the tube 90 degrees, so the “m” for milli approximates that character. Two rows spelling “MAKE” (or “MAKe”) are assembled, powered via a small circuit which [Joshua] assembled on a custom-etched board using the toner transfer process. The electronics are all wrapped up in a neat laser-cut acrylic enclosure which was designed in Inkscape.

It’s a neat little project which makes good use of a Nixie tube that is, by and large, unloved. It also recalls us of a misspent youth, writing silly words on scientific calculators using only the available Greek characters. Meanwhile, if you’re working on your own Nixie builds, we’ve featured some neat drivers that you might just find valuable.

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