A Retro-Futuristic Numitron Clock

Numitron displays — as explained here — are similar in form to Nixies or even VFDs. Instead of requiring around 120V to drive Nixies, and ~60 for VFDs, however, they call for just 2-3V. This presents huge advantages when trying to hack together your own old-school display, as outlined in Jelto Wodstrcil's Numitron Clock project.

Wodstrcil's device runs on an Arduino Nano, along with a DS3231 RTC module for accurate timekeeping. Six WS2821 RGB LEDs provide lighting to accompany the four IV-9 Numitron tubes. These are driven with the help of four shift registers, mounted to helper boards sourced from this page.

The whole thing is enclosed in an empty 1HE server power supply, which gives it a great worn retro-futuristic look. To enhance this effect, Wodstrcil added handles and mesh that he scrapped from an old case found at the flea market.

The dedicated UI appears to consist only of a power toggle switch, nicely protected by round metal protrusions. Time is set using a simple serial interface, making the whole setup very straightforward, and perhaps even enhancing its worn and apocalyptic future ethos!

Code for the build is available here, and while there’s not a clip of this particular build, you can see the driver PCB setup that it's based on in the video below.