Turning a Canon Typestar IV typewriter into a USB keyboard


05 Nov 2019, 19:43

I recently just finished a project where I ripped the guts out of an old battery-powered thermal typewriter and converted it into USB keyboard. It came out rather well, if I say so myself, although I do need to find something better to do with the USB cable.


The full writeup (including seven hours of video) is at http://cowlark.com/2019-11-03-keyboard/, but the executive summary is:
  • SMK spring over dome tactile linear switches (very nice) in a matrix layout --- sadly no diodes
  • The 15-char LCD screen presents itself as a USB serial port so the computer can write text onto it
  • PCB modification to remove the hard-wired typewriter-style shift key logic
  • Several more PCB modifications to convert matrix keys to more modifier keys
  • Based around a PSoC5LP development board
  • The paper feed mechanism still works (although I did have to remove the thermal print head), and makes a great phone stand
  • Quite a lot of terrible soldering
Sadly, the layout is a little cramped and hard to get used to, as it's short on keys, so I'm finding myself not actually using it. Sigh. It's the first time I've done one of these. WDYT?

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05 Nov 2019, 21:44

That's very cool! Nice job!

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