How would a keyboard like this detect simultaneous key presses? It seems like you'd either see only the lower-resistance key (if the resistances are orders of magnitude apart) or end up with a completely nonsense value.
Let's say that Q, W, and E are 1Ω, 2Ω, and 4Ω, respectively. I'll pretend they're wired in series to make the numbers work out nicely, but it should also work in parallel. If you measure 3Ω, then Q and W are pressed. 6Ω: W and E. 7Ω: all three.
