Chris Harrison has done some research on using scratching as an input device. In this video he demonstrates how simply scratching a wall or a desk could have some simple and inexpensive applications. Could you imagine controlling your room lights by scratching anywhere on the wall in the room you want to control? Or a coffee table that has a sensor so that you could use it to control your audio system?
"We present Scratch Input, an acoustic-based input technique that relies on the unique sound produced when a fingernail is dragged over the surface of a textured material, such as wood, fabric, or wall paint. We employ a simple sensor that can be easily coupled with existing surfaces, such as walls and tables, turning them into large, unpowered and ad hoc finger input surfaces."
Via: Procrastineering
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Simply brilliant! so you use the enveloppe and spectrum to identify the scratch caracteristics?
The only problem i see is if some wall structure density could make reflection on the wave that could delai and modify the envelope and spectrum and generate wrong interpretation of the reconizing commands.
the idea is nice!
Maybe by using two distant sensors(microphone) you could locate the scratch position and use the wal to draw =) the phase and delay difference would make it easy to locate
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Now to just take that built-in mic. on a laptop and place it on the bottom of laptop and let the weigh press the stethoscope-mic. against the surface and now you have a gesture table enabled device where ever you have you laptop. No fiddling with wires to set it up ore anything. Like the idea of that hack 🙂 … should make a nice project 🙂
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it would just be great to hear about a release of any kind of software to use with a modified microphone.
what is the present status of “locating sound source in 2d space using 2 microphones” ? is it already possible? i would be glad if 🙂
thx in advance :=)
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That’s very cool, I might just try to build one. I wonder how difficult it is to tell where the sound is coming from? With enough precision you could combine it with a projector to have an ad-hoc touchscreen on any ordinary wall on the cheap.
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@ peter:
Check out this link, they achieved full scratch position sensing using 4 sensors, though I expect you could do it with 3 since that’s all that is necessary for triangulation.
http://www.taichi.cf.ac.uk/
This object scratching project is awesome though! Using the frequency and timing domain characteristics is a pretty flexible and dynamic method.
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Wow. This is exactly why I read through Hacked Gadgets everyday. What a great idea!!!
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this is great. just awesome.. the best solutions are always the simpliest =)
loved it!
i wanna see this technology applicated, now!!
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This is an excellent system. Maybe you could use multiple sensors based on a wall or table to make it act as a touch screen or graphics tabled like surface.
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