On Tue, 5 Apr 2005, Carey Fisher - NCS wrote:

>
>   > You know the rest...a couple of years ago a co-worker showed
>   > me this new
>   > "optical mouse" that Microsoft was making.  I remember "it had
>   > as much CPU
>   > power as a 386" and stuff like that.  And you can buy them for
>   > less than
>   > $50 now.  And no one gives it a second thought.
>   >
>  Just how do optical mice (mouses?, meece?) work?
> Carey Fisher

In short, a dsp computer running in a chip takes snapshots of the desk 
under the mouse. Successive snapshots show the features moved as the 
mouse moves. The computer computes the difference between the pictures 
using correlation and sends the difference to the computer as a mouse 
packet.

Peter
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist