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Building a Pressure-Sensitive, Multi-Point TouchScreen?
sonamchauhan asks: "I'd like advice on building (yes, building) my own low-res touchscreen. The reasons for 'build' instead of 'buy' are: 1) to have it sense pressure (pressure sensing is quite expensive) and 2) to have it sense multiple points of contact simultaneously (which is a useful thing). Back in 1985, researchers at U.Toronto built (PDF file) a touch-tablet (not a touch-screen) that fulfilled both requirements (pressure-sensitive and multi-touch) and used only basic electronics: lots of diodes, A/D convertors, etc. Some 17 years later, it should be possible to build a touch-screen using the same techniques (possibly using layers of transparent conductive and insulating paint for the sensor paths.) Any comments? Some other links: a Microsoft paper (PDF file) describing a touch sensor painted onto a mouse, a basic FAQ on current touchscreen technology, and a slashdot thread that discussed building touchscreens (these links don't address pressure or multi-touch though)."
I would think that the time and effort that went into developing something like this, basically from scratch, would outweigh the "real" cost savings of not buying one off-the-shelf. I suppose if this is just for fun, than that's not really a concern, but if your time is worth anything at all, it ought to be considered.