So, once I’d taken this keyboard apart and plotted the wire “coordinates” of each key, I removed the wires from the circuit board. This left only a little 4×1.5″ circuit board on the end of the USB cable. I needed a way to make the wire contacts accessible, so I could connect them to whatever Part III is. (As of this writing, on July 5, I have yet to determine what that’ll be. You can see some concept sketches in the background, though.)
Attempt 1: Soldering
To avoid screwing up the existing contacts, I first tried soldering wires directly onto the exposed connectors, which lay opposite the slot. I got most of them on without soldering them to each other… and then I noticed that I still had to solder 18 more tiny wires side-by-side, and these ones were already falling off. Ouch.
Attempt 1.5: Stupidity
I failed a couple more times and tried to find a solution that would allow me to use the plastic sheets, since they already connected well with the circuit board.
As an experiment, I tried dripping solder onto a wire held over one of the contacts printed onto the plastic sheet. It melted. Duh.
Then, I tried taping foil and wire onto a contact. The wire pulled out before I could even test what I assume would be terrible connectivity.
Attempt 2: Tiny wires
Tiny copper wires. Twenty-six of them. Each with a protective coating that had to be scraped off with a razor to expose metal near the end, so as to make contact with the circuit board. They fell out even after I’d shoved the little grey plastic holder thingies back in.
Attempt 3: Less-tiny wires, hot glue, supplication
You won’t read this for about a week yet, but god DAMN am I happy tonight! I finally got this to work! I found a ribbon cable with wires a little bigger than the copper ones, and a little smaller than the ones that wouldn’t fit, and they fit perfectly. I sealed them in with hot glue as I went along, to avoid dislodging those I’d meticulously shoved in with tweezers.
I stripped the opposite ends and taped them into this breadboard. I’ll probably transfer them, since I don’t need a board with detachable positive/ground tracks on the sides, so it’s kind of a waste.
After hooking these up, I had to true the coordinates. Incomprehensibly, the bottom keyboard row (shift-Z-X-etc.) was seven kinds of screwy. But I tested out the mistakes, and now the coordinates are correct. Next problem: the weather in late July (Maker Faire Detroit) is sweltering. Even a short, thin jacket isn’t practical. How am I going to attach this to myself?
As a side note, the spam comments I get on here are pretty fun. A recent theme seems to be “it is not the perfect informaiton, but thank you for psotnig”. My favorite said only, “It — is intolerable.”
That’s all. Alex out!