Aha, thanks, I've never seen IR touch detection before, only the resistive stuff with the four wires. Interesting! Is it a matter of breaking direct beams, or something more sophisticated than that? The "resolution" of the touch seems like it must be.
Yes I haven't probed the serial port yet but I guessed 3.3v. I'll check and hook an arduino up to it and see if anything is occurring that I can get into. I have read a blog that reported that the linux console was being piped out to it at 115200 baud. Not quite sure what form it'll take, but I'll have a dig.
I want to be able to use the port to send commands to trigger a dimmer (probably via an arduino-a-like), a music player/radio and to poll for input from physical buttons (big snooze button on the top). Pi running the show and using the kobo as simply an interface is another option.