Researchers Turn Tables and Walls Into "Scratch Input" Surfaces 54
An anonymous reader writes "Researchers at Carnegie Mellon University's HCI Institute have developed a new input technology that allows mobile devices to use surfaces they rest on, like tables, for gestural finger input. This is achieved with some clever acoustic tricks — basically taking advantage of high frequency sound propagation through dense materials. Their video highlights some neat applications, such as controlling an MP3 player by scratching on a wall and muting a cell phone by scratching on a table. Further details are available in the academic paper (PDF)."
Triangulation (Score:1, Interesting)
I wonder if 3 stethoscopes could provide enough accuracy to turn your desk into a large drawing tablet.
Applications (Score:3, Interesting)
This has potential for a door lock. A cute application would be something that opens the door when the dog wants to go out. But scratch recognition without location information is going to be very limited in application.
With some positional information, it could be more useful. The speed of sound in wood is high, so you're going to have to correlate waveforms, not just time events. But that's not hard to do. I have no idea how much accuracy you could get, but it's not an expensive experiment to find out. Try four microphones at the corners of a table and correlate to line up the waveforms. (Three are enough for position, but with four, you get redundancy and can eliminate totally bogus position results.) Multi-touch is going to be hard, though.
It might be fun to set up a DJ mixing rig this way. No turntables, just a flat surface, maybe with outlines of turntables and faders to guide navigation.
Two Questions (Score:3, Interesting)
Won't a vibrating phone with this technology enabled cause some issues? Or not cleanly picking up the phone might end a call.
And another thing - how long before some huge corporation buys the rights to this technology (or patents it) and puts this out of reach of most consumers?
Re:Carnegie Mellon... (Score:4, Interesting)
Gestural input? (Score:2, Interesting)
The article says this researches has accomplished "gestural finger input". Although this would be very cool, it is not the case. The only thing this researcher has done is listening for sound, and if there's sound, do stuff. Compare it to the microphone input of the DS: if there's noise, you can do stuff, if there's no noise, do nothing. What the researcher added was a bit of complexity: a short noise changes mode, and a long noise activates the mode. That's nowhere near gestural input.
In fact, even if they had used 3 microphones (which would allow for random gestural input), the precision with realistic hardware on, for example, plastics, would be about an inch, or a couple of centimeters best case scenario. Forget about gestures on concrete walls.