One day you just have had it. Your wormsnest of wires and splotches of solder are just not doing it. And error checking is a nightmare. What do you do? You go back to the drawing board off course, and start designing your own PCB.
Or, so I did anyway. I always thought of myself as pretty handy, but I need to practise my soldering. And I’d need to grow a third arm, two for the iron and the solder, the third for holding the parts in place. So I followed the advise of my teacher in handicraft, “If your thumb is in the middle of your hand, you’d probably be great at computers”.
And why even use a computer when you can have someone build the board for you? Well, it’s actually kind of fun, don’t be intimidated by the idea. And it makes building your own keyboard a lot easier. You map the keyboard grid on a PCB, and a footprint matching your Teensy, or whatever you’re using. Send it off, get it back and just solder in diodes and the Teensy (equivalent).
PCB:s make for a more rigid construction too. In stead of only using a switch plate, where you probably need to glue the switches down, you solder them to a proper board. A lot better than a bundle of wires and hot glue.