Re: [CAD_CAM_EDM_DRO] Digitizer, Optical mouse hacking

I've heard those optical sensors won't work well on ANY surface. A problem
wouold probably surface if you try digitizing a piece of glassware or
perhaps a mirror that has been surface carved before digitizing.

Smoke

>The new optical mice on the market look like an ideal sensor with which to
>construct a 3D digitizer probe. Currently the Microsoft brand sell for

under

>$40 and seem to have amazingly high resolution for the detection of
>movement. The principal of the optical mouse design is that it replaces the
>mechanical ball and friction wheels with a laser led and sensor. The laser
>led operates automatically in two power modes. After a few seconds of no
>movement, the led intensity drops. As soon as there is movement of any

kind,

>the led steps up into high power for what I guess is to do with

resoloution.

>These mice will operate on any surface in and oritentation. Now my testing
>shows it is not possible to move the mouse even .001 without the led
>stepping up in power, but it is possible to get the led to step up without
>the cursor on the screen moving. This shows the sensing resoloution is
>greater than mouse resoloution. For the probe design, the top of the probe
>would have a patterened surface directly under the mouse led and sensor.

The

>lower down on the probe that the pivot point is, the greater the
>resoloution. For example a three inch probe pivioted at one inch from the
>bottom would multiply and movement by two. With the mouse static, any
>movement of the probe sideways could be detected as mouse movement. For the
>software, it would monitor the mouse port and any activity would cause the
>M-code trigger, the XYZ encoder positions to be logged and optionally the

XY

>of the mouse movement recorded for any post processing of the data. For the
>vertical trigger one of the mouse buttons could be adapted so that the

probe

>activates a mouse click which is also processed by the software.
>
>Graham
>
>