Re: [CAD_CAM_EDM_DRO] re: using optical mouse for DRO / servo feedback

Nigel Bailey wrote:

>Just come through from Farnell electronics (a distributor) on the new
>products is an optical mouse sensor for use on "a surface", it just reads
>the surface, be it a mouse pad, a bit of desk-top, an envelope (or possibly
>a dusty rail), and uses an on-chip camera and some signal processing to give
>400-800 counts per inch x and y. Quadrature or serial outputs, etc. maximum
>speed of motion it says are 12 inches per second.
>anyway manufacturer is AGILENT, and part number is
>ADNS-2051, looks promising
>
>

400 - 800 counts per inch? How can you make a measurement system where
there is
a 50 - 100% variation in gain? This will work for moving a cursor on a
screen, but
won't do for a motion control system. If it was a consistant scale, you
could at
least use it for a DRO. But, for a servo feedback system, you also need
a fairly
fast update rate, and I suspect this may not give that.

Jon