fingerworks!
Great to see someone-else with a fingerworks keyboard!
Sparkfun - a supplier of components, widgets, doohickeys and other frivolities - is now making its own hardware in the form of the Makey Makey, which turns just about anything into a keyboard. The Makey Makey started out as a Kickstarter project from a couple of MIT Medialab types, who used the money raised to commission …
" ...wood was a little too conductive and the 3mm gap between the panels wasn't isolating enough - a wider gap works,... "
Try putting a 1Megohm (or 2M or 500k) resistor in series with the contact wires. That would enable you to have a smaller wood gap while still being able to detect a finger press. Go on, do some real engineering.
Build your own TV game show buzzer system!
You have enough contacts, and it would take very little code to detect who pressed first, to light up individual lamps for individual buzzers, and a team lamp to indicate which teams buzzer was pressed first ...
... or of course you can just hack one of the quiz controllers for a Playstation or Xbox quiz game :-)
Back in the early eighties a local political party were trying to correlate several years' doorstep survey results to predict individual voter's likely voting intentions. This involved several people each having a different survey result list. They had to find a matching name entry and announce their survey's result. Another person applied "prediction rules" to the voter's combined history input - and marked up the new campaign list. It required a lot of mental concentration - and was very prone to human error.
A set of momentary switches on the Apple II ports plus a little Basic program "automated" the process. People just pushed their buttons for the appropriate survey result - and the "voting prediction" for that person's combination was made visible.
Can't remember when local political parties stopped knocking on doors. No doubt the new Government Snooper's Charter will provide a better source of information.
Huh. That conductive paint looks interesting.
I got into Arduino hacking so I could make programmable sex toys (I've built a prototype vibrator guaranteed not to get the user off--it shuts down when you get close--and another that's an Arduino cobbled to a Neurosky EEG chip so that you can turn a sex toy on or off just by thinking about it, hands-free). This tech looks like it has all kinds of interesting potential uses. I'm already envisioning conductive ink painted on a person, with software on the Arduino that will trigger changes in the output when someone else touches it...dunno if the normally (relatively) low resistance of skin will be a problem though.
Back to the workshop!
Conductive paint probably won't work, skin alone is of a very similar conductivity.
That said, you can probably build a variable resistor into someone's skin, by using a pair of contacts and measuring the resistance between each of them and to the other person.
If that works, then a 2D touchpad is simply a case of another pair of contacts and multiplexing.
This calls for an experiment!
Just wondering if anyone has yet produced an RGB led that can be polled using a digital comms signal impressed on its two DC power wires. The idea is that you drape the power cable round the Xmas tree and just attach the desired leds with a bee-sting type of connection. A small controller can be programmed to assign each led dynamically to a group - and then poll the groups to set their changes in colour/intensity.
A proper PC and a camera input might be needed initially to cycle through the leds to establish their positions on the tree - if you want pretty moving patterns.
Its feasible, something along the lines of a reverse RFID which upon receiving a code lights up with the last 4 digits of that code representing the colour intensity and brightness.
Maybe use a PIC10F222 or similar, would be pricey but they are down to 22p in bulk now.
A similar circuit exists which uses discrete transistors to get shift register functionality, published in EDN around 1993 IIRC.