This project as described in www.surfncircuits.com came about because I needed a retro looking linear meter for my espresso maker water tank. I’m always running out of water in my espresso maker, and a cool display letting me know how much water is left and to let me know when to fill it up is definitely needed. In this project, I’ll create a HAT for the Raspberry Pi that can drive two IN-9 or IN-13 linear Nixie tubes. While I’m using this HAT as a single water meter display, this same linear display would be great for showing temperature, bar graphs, audio VU meters, even surf heights by days of the week. The Nixie Tube Power Supply, designed in an earlier blog will work perfectly to drive up to four of the IN-13 Nixie tubes or one IN-9 Nixie tube.
First, I decided to upgrade from the Raspberry Pi Model B to a more recent Raspberry Pi Zero W that I had on hand. Wired Ethernet is so ~ 2013 after all, and wireless would be a lot more convenient. Next, I designed a 3D printed case for it, as my old laser-cut-acrylic-and-glue case also looked very dated. Finally, I replaced the software with a new program designed to poll the data from my octoprint server. In less than an afternoon, I had turned the old temperature/humidity display into something useful.
Since this power supply is just a fun design for an upcoming Nixie tube clock project of mine, I have the time to achieve ESE. While in Part 1 I described the equations and simulations, in this Part 2, I collected experimental results to complete the design. In the process of finalizing the design, I was able to discover a couple of key design improvements and I’ll share these changes with you. The updated schematic, BOM, Kicad Layout, and design files are located at Github.
The renaissance of Nixie tube popularity amid the nostalgia surrounding older tech has made them almost prohibitively expensive for individual projects. Seeing an opportunity to modernize the beloved devices, [Connor Nishijima] has unleashed this new, LED edge-lit display that he has dubbed Lixie.
We featured his prototype a few years ago. That design used dots to make up each character but this upgrade smooths that out with sleek lines and a look one would almost expect from a professional device — or at the very least something you’d see in a cyberpunk near-future. The color-changing Neopixel LEDs — moderated by a cleverly designed filter — allow for customization to your heart’s content, and the laser-cut acrylic panes allow for larger displays to be produced with relative ease.
The image above (and the video below) show two revisions of the most recent Lixie prototypes. There is a huge improvement on the right, as the digits are now outlines instead of single strokes and engraved instead of cut completely through the acrylic. The difference if phenomenal, and in our opinion move the “back to the drawing board” effect to “ready for primetime”. [Connor] and his team are working on just that, with a Tindie preorder in place for the first production-ready digits to roll off their line.
Considering that Nixie Tubes were originally considered too expensive for mass-produced items like clocks, it’s ironic they’re seeing a revival in hobbyist projects for just that purpose. Lixie, then, may fit the purpose for those seeing a cheaper solution without sacrificing on the quality of the result. The design is fully open-source, so get to hacking!
The Weatherclock is more than just a clock sporting Nixie tubes and neon lamps. There is even more to it than the wonderful workmanship and the big, beautiful pictures in the build log. [Bradley]’s Weatherclock is not only internet-connected, it automatically looks up local weather and sets the backlights of the numbers to reflect current weather conditions. For example, green for roughly room temperature, blue for cold, red for warm, flashing blue for rain, flashing white for lightning, scrolling white for fog and ice, and so on.
The enclosure is custom-made and the sockets for the tubes are seated in a laser-cut plastic frame. While seating the sockets, [Bradley] noticed that an Adafruit Neopixel RGB LED breakout board fit perfectly between the tube leads. By seating one Neopixel behind each Nixie indicator, each number could have a programmable backlight that just happened to look fabulous.
With an Electric Imp board used for WiFi the capabilities of the Weatherclock were rounded out on the inside. On the outside, a custom enclosure ties it all together. [Bradley] says his family had gotten so used to having the Weatherclock show them the outside conditions that they really missed it when it was down for maintenance or work – which shouldn’t happen much anymore as the project is pretty much complete.
It’s interesting to see new features in Nixie clocks. Nixie tubes have such enduring appeal that using them alone has its own charm, and at least one dedicated craftsman actually makes new ones from scratch.
Three years ago we covered [Dalibor Farnby]’s adventures in making his own Nixie tubes. Back then it was just a hobby, a kind of exploration into the past. He didn’t stop, and it soon became his primary occupation. In this video he shows the striking process of making one of his Nixie tubes.
Each of his tubes get an astounding amount of love and attention. An evolution of the process he has been working on for five years now. The video starts with the cleaning process for the newly etched metal parts. Each one is washed and dried before being taken for storage inside a clean hood. The metal parts are carefully hand bent. Little ceramic pins are carefully glued and bonded. These are used to hold the numbers apart from each other. The assembly is spot welded together.
In a separate cut work begins on the glass. The first part to make is the bottom which holds the wire leads. These are joined and then annealed. Inspection is performed on a polariscope and a leak detector before they are set aside for assembly. Back to the workbench the leads are spot welded to the frame holding the numbers.
It continues with amazing attention to detail. So much effort goes into each step. In the end a very beautiful nixie tube sits on a test rack, working through enough cycles to be certified ready for sale. The numbers crisp, clear, and beautiful. Great work keeping this loved part of history alive in the modern age.