We’re not sure about the name of this Nixie tube filament meter that [Scott M. Baker] built. He calls it a “filadometer”, perhaps a portmanteau of “filament” and “odometer”, in which case it makes sense. It may not flow trippingly from the tongue and we can’t come up with anything better, but whatever moniker you use it’s actually a pretty cool build.
The filadometer started life as something completely different and utterly typical for Nixie tube projects – a temperature and humidity gauge. [Scott] decided to recycle the eight-tube display to keep track of his Prusa, and in doing so he reveals a pretty remarkable degree of forethought in his design process. The original Nixie display has all the usual trappings – the driver chips, the shift registers, and the high voltage power supply. What stands out is the modularity of his design: the tube sockets and drivers live on a backplane PCB, with a Raspberry Pi and a separate HV supply board plugging into it. The original display had a Model B Pi, so there was plenty of room for a new Zero W. A new printed case and a little programming to capture the filament use from Octoprint is all it took to put this nifty little build back in action. The video below shows the details.
If you want to display numbers, just go for Nixies. There’s no better way to do that job, simply because they look so cool. Unfortunately, Nixies require high voltages, controlling them is a tiny bit strange, and they suck down a lot of power. These facts have given us a few Nixie alternatives, and [Dave] is here with yet another one. It’s a light pipe Nixie, made from acrylic rod.
The idea of using lights shining into a piece of acrylic to display a number is probably as old as the Nixie itself. There were a few tools in the 60s that used side-lit plastic panels to display numbers, and more recently we’ve seen a laser-cut version, the Lixie. This display is just ten sheets of acrylic etched with the numbers 0 through 9. Shine a light through the right acrylic sheet, and that number lights up.
You can do just about everything in acrylic, and it’s already used for a light pipe, so [Dave] grabbed some acrylic rod and bent it into the shape of a few numbers. With a little work, he was able to make his own FauxNixie by mounting these numbers in a carefully modified lamp socked wired up with ten individual LEDs. The results make for big, big, big Nixie-style numbers, and the perfect clock for the discerning glowey aficionado.
The shield uses HV5812 drivers to handle the high-voltage side of things, a part more typically used to drive vacuum fluorescent displays. There’s also a DHT22 for temperature and humidity measurements, and a DS3231 real time clock. It’s designed to work with IN-12 and IN-15 tubes, with the part selection depending on whether you’re going for a clock build or a combined thermometer/hygrometer. There’s also an enclosure option available, consisting of two-tone laser etched parts that snap together to give a rather sleek finished look.
[Tony] built a high-efficiency power supply for Nixie tube projects. But that’s not what this post is about, really.
As you read through [Tony]’s extremely detailed post on Hackaday.io, you’ll be reading through an object lesson in electronic design that covers the entire process, from the initial concept – a really nice, reliable 170 V power supply for Nixie tubes – right through to getting the board manufactured and setting up a Tindie store to sell them.
[Tony] saw the need for a solid, well-made high-voltage supply, so it delved into data sheets and found a design that would work – as he points out, no need to reinvent the wheel. He built and tested a prototype, made a few tweaks, then took PCBWay up on their offer to stuff 10 boards for a mere $88. There were some gotchas to work around, but he got enough units to test before deciding to ramp up to production.
Things got interesting there; ordering full reels of parts like flyback transformers turned out to be really important and not that easy, and the ongoing trade war between China and the US resulted in unexpected cost increases. But FedEx snafus notwithstanding, the process of getting a 200-unit production run built and shipped seemed remarkably easy. [Tony] even details his pricing and marketing strategy for the boards, which are available on Tindie and eBay.
We learned a ton from this project, not least being how hard it is for the little guy to make a buck in this space. And still, [Tony]’s excellent documentation makes the process seem approachable enough to be attractive, if only we had a decent idea for a widget.
Classix Philly One Oh Seven Nine is your home for Philly soul right at the top of the dial, and now you know why this writer isn’t allowed on the Hackaday podcast. That phrase, ‘top of the dial’ doesn’t mean much these days because we all have radios with a digital display and seek buttons. There was a time when radios actually had dials, but [glasslinger] is in a class all by himself. He’s adding a digital display to a 1940s radio, and he’s doing it with Nixie tubes.
The circuitry for the digital display for this AM radio requires getting the frequency the radio is tuned to. This is done by counting the oscillator frequency, then subtracting the IF. [glasslinger] is doing this with an Arduino (hey, it’s a legitimate engineering choice) and a 4040 12-bit binary counter as a pre-scaler. The Arduino does the math and then drives a few 74141 Nixie drivers, which then display the frequency of the receiver in beautiful glass tubes. Add in a single neon bulb for the thousands digit, and you have a four-digit display that will tell you the frequency you’re tuned to on an old AM radio.
The rest of the build consists of fixing up an old radio and gluing the veneer down again with modern glues that will last another seventy years. The finished cabinet was sanded, a bezel for the display was added, and since [glasslinger] has the equipment, he made a new, long neon tube to light up with the volume of the radio. And you thought a cat’s eye detector was cool.
This build is a tour de force, and something that is so incredibly modern but at the same time built on vintage technology. If you’ve got an hour and a half, we highly recommend checking out the build video below.
In this week’s edition of, ‘why you should care that Behringer is cloning a bunch of vintage synths’, I present to you this amazing monstrosity. Yes, it’s a vertical video of a synthesizer without any sound. Never change, Reddit. A bit of explanation: this is four Behringer Model Ds (effectively clones of the Moog Minimoog, the Behringer version is called the ‘Boog’) stacked in a wooden case. They are connected to a MIDI keyboard ‘with Arduinos’ that split up the notes to each individual Boog. This is going to sound amazing and it’s one gigantic wall of twelve oscillators and it only cost $800 this is nuts.
Tuesday is Fastnacht day. Fill your face with fried dough.
It’s a new Project Binky! This time, we’re looking at cutting holes in the oil sump, patching those holes, cutting more holes in an oil sump, patching those holes, wiring up a dashcam, and putting in what is probably the third or fourth radiator so far.
While it might be tempting to start soldering a circuit together once the design looks good on paper, experience tells us that it’s still good to test it out on a breadboard first to make sure everything works properly. That might be where the process ends for one-off projects, but for large production runs you’re going to need to test all the PCBs after they’re built, too. While you would use a breadboard for prototyping, the platform you’re going to need for quality control is called a “bed of nails“.
This project comes to us by way of [Thom] who has been doing a large production run of circuits meant to drive nixie tubes. After the each board is completed, they are laid on top of a number of pins arranged to mate to various points on the PCB. Without needing to use alligator clamps or anything else labor-intensive to test, this simple jig with all the test points built-in means that each board can be laid on the bed and tested to ensure it works properly. The test bed looks like a bed of nails as well, hence the name.
There are other ways of testing PCBs after production, too, but if your board doesn’t involve any type of processing they might be hard to implement. Nixie tubes are mostly in the “analog” realm so this test setup works well for [Thom]’s needs.