Nixies And Raspis For A Modern Vintage Calculator

There are a few very rare and very expensive calculators with Nixie tube displays scattered about calculator history, but so far we haven’t seen someone build a truly useful Nixie calculator from scratch. [Scott] did just that. It’s a complete, fully-functional electronic calculator with all the functions you would expect from a standard scientific calculator.

The calculator uses IN-12 Nixies, the standard for anyone wanting to build a clock or other numerical neon discharge display. Each Nixie is controlled by a K155D driver chip, with the driver chip controlled by an I2C IO expander.

The keypad is where this gets interesting; electronics are one thing, but electromechanicals and buttons are a completely new source of headaches. [Scott] ended up using Cherry MX Blue switches, one of the more common switches for mechanical keyboards. By using a standard keyboard switch [Scott] was able to get custom keycaps made for each of the buttons on his calculator.

The brains of the calculator is a Raspberry Pi, with the I2C pins going off to listen in on the several IO expanders on the device. A Raspi might be a little overkill, but an Internet-connected calculator does allow [Scott] to send calculations off to WolframAlpha, or even the copy of Mathematica included in every Pi.

[Scott] has put his project up on Kickstarter. Videos below.

18 thoughts on “Nixies And Raspis For A Modern Vintage Calculator

    1. I wouldn’t call a Pi a microcontroller…
      It may be, but the main use of it is a small embedded PC complete with an OS (Almost always linux)
      I applaud the effort going into the build, but the electronics need work. Expectations fell short when I saw a Pi was used as a controller.

      1. .. I cant edit my post ..
        I should mention that I would be much more impressed if he programmed a PIC or AVR to do the heavy lifting.

        As an aside… Find someone fluent with steampunk and work with them to get a kick A$$ case for that thing. It would look killer.

  1. I actually happen to own one of those heavy “rare” nixie calculators. Never really paid attention into any details of it, as I only bought it in order to salvage the nixies into better use. It was cheap, 15€ if I remember correctly, and it worked somewhat, but not perfectly. Maybe I’ll start putting it back into order, as it still is rather complete, thanks to my lack of free time. Maybe some disassembly photos and some blogpost when that happens…

    1. Nixie tube calculators aren’t rare, if you watch ebay you can pick them up for nothing. Of course they’re all a few decades old and deteriorating in every way so they need restoration.

  2. I’m sorry, but if a build contains a Raspberry PI then it cannot be claimed ‘from scratch’. It’s like baking a cake with one of those box packages from the store instead of mixing the eggs, flour and sugar yourself, and then passing it off as ‘from scratch’. I’m not saying it isn’t a nice build, nor that I wouldn’t eat pre-mixed cake – just be careful what you claim! :-)

  3. “Hello, I’m here for my internet money.”

    This belongs on something like Tindie, not Kickstarter. There’s nothing being funded; he’s already done, and just wants to sell his kit.

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