Nixie tubes: these electronic devices, which can display numerals or other information using glow discharge, made their first appearance in 1955, and they remain popular today because of their cool, vintage aesthetic. Though lots of companies manufactured these items back in the day, the name ‘Nixie’ is said to derive from a Burroughs corporation’s device named NIX I, an abbreviation of ‘Numeric Indicator eXperimental No. 1’.
We liked this recent project shared on reddit, where user farrp2011 used Raspberry Pi to make his Nixie tube display smart enough to tell the time.
Farrp2011’s set-up comprises six Nixie tubes controlled by Raspberry Pi 3, along with eight SN74HC shift registers to turn the 60 transistors on and off that ground the pin for the digits to be displayed on the Nixie tubes. Sounds complicated? Well, that’s why farrp2011 is our favourite kind of DIY builder — they’ve put all the code for the project on GitHub.
Tales of financial woe from users trying to source their own Nixie tubes litter the comments section on the reddit post, but farrp2011 says they were able to purchase the ones used in this project for about about $15 each on eBay. Here’s a closer look at the bulbs, courtesy of a previous post by farrp2011 sharing an earlier stage of project…
Digging through the comments, we learned that for the video, farrp2011 turned their house lights off to give the Nixie tubes a stronger glow. So the tubes are not as bright in real life as they appear. We also found out that the drop resistor is 22k, with 170V as the supply. Another comments section nugget we liked was the name of the voltage booster boards used for each bulb: “Pile o’Poo“.
Upcoming improvements farrp201 has planned include displaying the date, temperature, and Bitcoin exchange rate, but more suggestions are welcome. They’re also going to add some more capacitors to help with a noise problem and remove the need for the tubes to be turned off before changing the display.
And for extra nerd-points, we found this mesmerising video from Dalibor Farný showing the process of making Nixie tubes: