Phalanx
A clock built with six authentic soviet vacuum fluorescent display (VFD) tubes, a custom designed circuit board, firmware and 3d-printed case

It features

  • 6 Authentic ИВ-6 (IV-6) Soviet VFD tubes
  • Wifi connected setup and control with an ESP M2
  • Various display modes for time
    • Without seconds, displaying on 4 tubes with rotating positions
    • With seconds, displaying on all 6 tubes
  • Display dimming
  • Timezones, automatic DST handling
  • Ability to play progress in current song on Spotify
  • No hardware clock, internet is required on startup to fetch time from NTP.
  • USB Type-C connector

Goals
Mostly, I wanted to learn. I'm not shy to admit that I've heavily looked at other VFD and Nixie projects on especially the schematics. Working with these now has given me the confidence to start developing different projects with different tubes going forward. I'm probably still making mistakes along the way, but I'm having fun making these which is the most important!

Most notably I wanted this project to have the following:

  • USB Type-C
    Anything new should use this plug where appropriate. My hobby projects should not be an exception!
  • Custom board design
    I'm personally not a fan of the aestethic of including LEDs in VFD/Nixie projects. Instead I chose to rely on the decimal points and evenly spread out the tubes, kinda like on the Divergence Meter project
  • Custom firmware
    I'm a software engineer by trade, and wanted to get some more experience with the Arduino APIs and C++ under my belt.

Schematics & PCB
An EasyEDA importable format has been attached in the comments.

I'm using a custom footprint for the IV-6 tubes which is in use by the PCB, with some slightly enlargened pin holes for each of the pins - made it a lot easier to place the tubes on the board!


3D Model for case
I've made a basic top-covering case which serves my needs right now - but I still consider this a work-in-progress as I'd like a case that fully encloses the device in the future. The case has holes for brass threaded inserts so the board sits securely in place.

Firmware
Can be found on Github. Code is nothing too fancy as it's a hobby project but I'm trying to at least have it set up for future VFD and Nixie projects. There are some modified libraries so be sure to look at the readme before compiling.

Cost
Board + shipping at JLCPCB: ~15 GBP (should give 5-10 boards)
Components: ~10 GBP at LCSC
IV-6 Tubes: ~10 GBP for 6, imported from Ukraine on Ebay
ESP-M2: ~1 GBP/each on Ebay
Roll of PLA: ~20 GBP on Amazon
Brass Threaded Inserts: ~5 GBP on Amazon

Sources
These were not documented initially, but I'll update this page when I come across them again on the internet, there's some amazing VFD/Nixie projects out there currently!