So approximately 2000 years ago I got a set of 6 nixie tubes as a gift. WTF is a nixie tube you ask? This is a nixie tube:

File:ZM1210-operating edit2.jpg

It’s an device for displaying all ten digits (0 through 9) using “glow discharge" (that thing that makes old incandescent lightbulb works), while looking really really cool.

The tubes I have are IN-17s and they operate at 180V. That is a lot of volts and it was pretty scary for me putting the circuit together since I’ve never worked with such high voltages. Fortunately, these works at relatively low amperages so I only have to worry about pain, not death.

Now, you might be wondering what I need to drive these things. The answer would be a Russian K155NA1 Driver Chip, which is basically a high voltage Binary-Coded Decimal decoder and a circuit to step up wall wart DC voltage (9V at 1a) to 180V. Thankfully a nice person on the internet made an arduino shield to do all this called the ArduiNIX

Here’s my completed display:

I’m still trying to understand how the circuit works. There are 20 pins and 4 grounds, so I can apparently control a total of 80 digits. I’m only using 60 digits in this setup (10 digits per tube times 6 tubes), but I’m still pretty lost when reading the demo code

My current understanding is that I have 2 BCDs which I can control with 8 pins (4 each, which makes sense since 2^4 = 16 > 10 digits), and I can control the 4 anode (aka ground) pins. From the code it seems I have to display 2 digits at a time, but I’m not at all clear how the digits are split up. That will be the subject for my next post!