Sawed Off Keyboard

Have you ever had to cut a piece of furniture in two to get it into a new place? Yours truly has, having had to cut the longer part of a sectional sofa in two to get it into a high-rise apartment. That’s what [Charles]’ sawed off keyboard immediately reminded us of. It sounds just as crazy, but brilliant at the same time.

In [Charles]’ case he wanted a keypad whose keys were customizable, and that would make a single keypress do common things like cut, copy and paste, which are normally ctrl-X, ctrl-C and ctrl-V in Windows. To do that he literally sawed off the numeric keypad from a full-sized keyboard. He also sawed off the end to the left of the QWERTY keyboard, and glued it onto the open end of his keypad.

The circuit board was too wide to fit in his new keypad, but he couldn’t stretch out the connections from the keypad’s keys to the board. So he did what any self-respecting hacker would do, he cut the circuit board where there were a manageable number of traces, leaving one part that would fit inside the keypad and another part that he could connect the traces to using a few wires. Lastly, he’d started with a PS/2 keyboard but he wanted USB output and programmability. So he redirected the PS/2 wires to an Arduino compatible Pro Micro and wrote some conversion code which you can find on his GitHub.

What other transformations can we do to keyboards? [Shrodingers_Cat] combined his with some DVD case covers to come up with a pedal board for use with his feet. And given that the keys on the numeric keypad are redundant, [Kipkay] put it to use as a hiding place for valuables instead.

45 thoughts on “Sawed Off Keyboard

      1. LOL that didn’t even cross my mind. I guess that I am closer to the hacker world than the real world :)

        Speaking of the real world … Is it still out there? Last time I saw the real world the resolution was excellent but the game play really sucked.

  1. For $0 this is a great hack but for the time invested it seems like a bit of a waste. I dunno, I guess my personal preference is to have cleaner solutions/builds/hacks when it comes to things you are going to use daily.

  2. LOL! I’ve done something similar myself. Years ago I had an “all-in-one” ascii terminal (along the lines of this one, though this one isn’t mine: and I literally sawed the keyboard off the front and reattached it back with a long ribbon cable so I could sit with the keyboard in my lap. My Dad thought it was funny and he helped me make a little angled holder for the keyboard out of wood. And that was my terminal for a number of years. I wonder if I still have a photo of that thing anywhere…

  3. I did this too, but I used a Teensy which I wired more or less directly to the keys. Teensy3.2 can be a USB Keyboard, and customising the keys is a breeze.
    This way you dont have to keep this other part of the keyboard PCB around (albeit out of sight).

        1. The handle is “coaxial” with the blade, as opposed to perpendicular.
          The blade is installed “backwards” and the saw is pulled on the cutting stroke instead of pushed. With the “D” type handle (perpendicular) the proper use is having the blade positioned for a cutting stroke with a push, and the sawyers other hand at the opposite end of the saw to steady it.

  4. i dont know why you would opt to go from ps2 to arduino for usb. id cut out the middle man and matrix the switches/membrane directly to the arduino’s gpio. run it up as a 4×5 matrix and debounce in software. you only need 17 of those 20 possible inputs. since you have 3 inputs left over, you can put the 3 leds into the matrix. when the leds come up during the scan you can z-state the inputs to to turn them off, or leave it low to enable them. so you can have inputs and outputs on the same matrix.

      1. there are libraries for matrixing and software debounce as well. then its just a $4 pro micro to go straight from gpio -> usb. you also cut out a lot of protocol latency having to buffer up serial data from the ps2 interface, reformat, remap, and retransmit over usb.

  5. Slow day at the office? In to the retro garbage aesthetic? Can’t afford a <$5 to buy a brand new USB number pad keyboard?

    I would be impressed if my 7 year old did this using LEGO blocks…otherwise this is an ideal project post for

  6. Well even though I have 4 different plug in numpads, USB and PS/2 AND a wireless one, I’m bookmarking this because it offers useful insights into messing with keyboard protocols and mapping and arduino/avr.

    Have several KB projects I want to get on with, including palm folder to android tab and palm folder to bluetooth via dollar store camera shutter. Maybe model M compact to wireless.

    1. Sounds good.

      Personally I’ve been thinking about making my own keypad using levered microswitches, I like the smooth action of those.
      I’d need to design some kind of holder and external keys and case though, but without messing up the action.

  7. A keypad is like 8 bucks on the usual Chinese sites, and I’m not saying to not do the custom keyboard hack but my suggestion is to use that keypad and a MCU to give the keys your own output to bypass the whole sawing mess.
    And in fact you could just leave it as it is internally and put an arduino or something in between it and the computer (hidden inside the pad) to remap the keys.

    If you like luxury you can also use a cherry keys keypad as basis for it.

      1. Well that’s why I pointed out I meant to use a standard keypad, feed it in an arduino, output modded keys to a computer.
        Same thing as this project except using a existing small keyboard instead of modifying a full size one.

        And yes there are 2 utilities on windows (one of which is very old) to remap dynamically via software, but that’s windows and it requires software to be started.

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