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Optical Mouse Used As Cheap Motion Sensor
drphil writes " Dr. Tuck Wah Ng, a member of the Faculty of Engineering at the National University of Singapore uses an optical mouse as a cheap non-contact motion sensor in his research. If a resolution of a little less than 60 microns is sufficient, you really can't beat the price. Dr. Ng has studied the viscoelastic deformation of plastics using a hacked optical mouse - published in J. Chem. Ed. vol 81, p 1628, 2004. You'd need to be a subscriber of the journal to see anything but the abstract, but any university science/chemistry library would have a copy of this issue of the Journal of Chemical Education. (Viscoelastic deformation, in plain English, is the degree to which a plastic stretches when you pull on it)"
That's a nice link there, I'm sure the first 1 or 2 people who saw it may have been interested.
Researchers looking into the hearing of flies attach the fly to a fixed support above it, and allow it's feet to touch a ping pong ball dotted with sharpie-marker dots. The ball rests on an optical mouse with some foam to hold it in place. By playing sounds from different directions and measuring where the fly moved in reaction they where able to determine how directionally-accurate the hearing of the fly was.
This is all per some TV show, maybe Discovery's This Week
60 microns is too low a resolution for that purpose.
Isn't this what mice do already?
Well, an optical mouse is actually a rather complex piece of work that goes a bit beyond a sensor (which in the case of a mouse is actually a minicam), just pull the circuit board from one and have a look. Then add in the cost of the plug, wire, etc.
Mice are cheap, and you can use the time you would have spent designing and building a data acquisition unit doing your real work.
Where I can't get what I want, or where what I want cost thousands of dollars when I can build it myself, better, for ten, I build, and I'm glad to do it.
When I can buy what I need off the shelf for twenty five dollars, or spend a week designing and building it myself for twenty dollars, well, I usually just go buy the sucker (unless I'm simply smitten by the intellectual challange of the thing for some reason).
But here is what I suppose is the biggest reason for using the mouse:
The software is already written, so you can just plug it in and it works.
KFG