Nixius - An ARM powered Nixie Clock

Hi there! I know that this isn't an arduino projects, but it could still be interesting.

So basically... A while ago I decided to make a Nixie clock. Of course Nixie clocks seem to be really popular and you can find many examples around. Most of them seem to be powered by a complicated power supply and use old Nixie drivers to drive them. Usually in a combination with arduinos with through hole components and big PCBs.

Well I decided to take a bit different approach. Instead of using Nixie drivers I used transistors - and a lot of them. For the power supply I took some of the designs from around the internet and built everything to be as cheap as possible.

I used an STM32F0 64 pin micro to drive everything - the cheapest STM ARM micro that I could find. For the Nixies I decided to use IN-1s. I made some custom PCBs to hold everything and I used as much SMD components as possible. Why? To make it cheaper. And because 10x10cm PCB is not only cheaper but also nicer to look at.

Features? Clock, temperature display (using DHT11 or DHT22 - I was planning on using the DS18B20 but I lost my mind trying to make the OneWire protocol work) and auto power off. Basically the clock will power off (and turn on) at a preset time - useful for bedrooms and in places where you don't want the nixies shining during the night.

Anyways... enough of the babble... some pictures:

Bare PCBs:

Completed Thing in a nice custom case:

Temperature display:

And another for the end:

I do plan on releasing everything (code, PCBs, ...). I just need some time to gather everything. And questions, comments will be welcome!

Perhaps this will interest you. Now that the Ardunix site seems to be dead, I had made an attempt at making a Nixie tube clock, based on the Atmel 328P and the fewest possible number of external components. It all fits on a PCB of 6 x 5. You can program it using the Arduino IDE.

I had to learn a lot of tricks the hard way, and so am I posting the code to help others.

The software is here:

The schematics are in the Instruction manual from that page.

The code has a bunch of tricks in it that might come in useful. It's well commented, so it might help with things.

BTW, love the IN-1s. They are my favorite as well...

One thing that I really wanted to avoid (and did) was using the old 74141 that everyone seems to be using. That's why I went with discrete transistors instead. But I have seen many Nixie designs out there because everyone seems to be doing it.

Also an ARM powered micro is cheaper as well. The STM32F0 that I am using costs less than an Atmega 328, is more powerful (32 bit, includes RTC, ...) and has enough pins to drive everything.

Yes, you're right the 74141, (K155 is the Russian equivalent) is getting a bit long in the tooth, expensive and quite difficult to find. It has the advantage of being really small and robust, but it's days are definitely numbered.

So, I've been looking for an alternative. What I have found is this HV5812 driver from Supertex:

But because this has a maximum operating voltage of 80V there will need to be some biassing going on. What I do like is the fact that the outputs are push-pull.

On the downside: it is also expensive, large (28 pin) and also quite a rare part with a not immediately obvious protocol to drive it.

Are you thinking of making some PCBs available to others to have a play with?

Oh, one other point, I solved the night time brightness problem by having auto dimming, using an LDR to sense ambient light.

Sorry for a late reply. I've been a bit busy lately.

As I said in the first post - I do plan on open sourcing the whole thing. I just need to find a bit of time to gather everything and post it. And maybe fix one or two minor things.

As for the brightness problem. I don't like LDRs really. Especially not in this case. I want the clock to be visible when I am watching TV for instance. But I don't want it to be turned on when I am sleeping. So I just have the thing programmed to turn off a bit earlier than when I usually get to bed.

Here we go! I finally found the time to put everything online.

Github and hackaday project info:

You can find pretty much everything that you need there.