LED Touch Sensing
From the same brilliant mind that brought the multi-input touchscreen I posted on last week, comes the LED touch sensing project. The creator, Jeff Han, has several projects on his site dealing with new, revolutionary computer interface systems. This one in particular caught my attention as I was browsing his site. The video looks like a basic version of the touchscreen from last time only this interface is simply made of LEDs. I really wish there was more information on this because this would be something that I would love to try to implement. However, the only info the site gives is the following cryptic message.
Two scalable techniques for enabling ordinary LED matrices to simultaneously act as multi-touch input devices. In 1977, Forrest M. Mims reminds us in one of his “Engineer’s Notebooks” that LEDs can also be used as photodiodes…
Maybe I’ll have to find this source myself but I am now determined to experiment with LEDs in this way.
Neat! I did a bit of google-spelunking, and came up with:
http://www.merl.com/reports/docs/TR2003-35.pdf
http://forums.parallax.com/forums/default.aspx?f=5&m=108974
which seems like it would be useful.
Comment by Mark VandeWettering — February 17, 2006 @
very nice mark - I’ll definitely be checking those resources out.
Comment by leadingzero — February 19, 2006 @
Forrest M. Mims (the 3rd?) is the guy who writes(wrote?) engineers mini-notebooks sold at radioshack. lots of basic electronic info in those.
Comment by Yusaku — February 19, 2006 @
Its not actually a touchscreen then is it?
Comment by Gary — February 20, 2006 @
No, but it functions as one - and that’s what is cool about it. I never knew that LEDs could be used as sensors like this.
Comment by leadingzero — February 21, 2006 @
if led’s can be used as photo resistors as the “cryptic statement” says, then this is easy! when you cover the little recess that a diode hides in, the resistance in the circuit should change because of the reflection of light from of your finger.
Comment by ehren — June 2, 2006 @