I’ve alluded before to some of the new projects I’m working on, and one if them is finally ready to start showing off, at least a little bit. I only wish I was allowed to tell more details, because the best part is still under wraps!
The electronics are pretty simple: each key mechanism is connected by fishing line to a solenoid; the multi-story solenoid bank is visible in the background. Each solenoid is connected to a MOSFET, which is in turn connected to the output of a 74HC595 shift register (with the exception of the shift key, which is controlled directly by the Arduino for timing reasons). The 595 is controlled by an Arduino that translates the serial data from USB to trigger the proper key.
It still needs some work: as you can see in that video, the return key doesn’t always activate when “pressed,” because it has a different mechanism than the other keys. In the bigger picture, right now it is output only, but eventually, it will also send input to the computer using a scheme very similar to that described in this Instructable. On the aesthetic side, the solenoid bank will be hidden in the final project.
Others have done some pretty cool hacks with typewriters: the Instructable is one, and the same creator has done something similar for iPads, all available at www.usbtypewriter.com. There’s also this typewriter-to-teletype hack, which uses an electronic typewriter and has both input and output. As far as I know, though, this is the first project where the typewriter keys move “by themselves” while typing.
That’s the what; of course, the remaining question is why. Unfortunately, my collaborator has sworn me to semi-secrecy. So, if you want to find out where this is all going, you’ll either have to come back for a later post, or, if you’re in Toronto, come visit me at one of the Site 3 open house nights (Thursdays from 6-10). You can see it in action, and maybe even try it yourself!