Re: Optical mouse for DRO anyone?

Hello,

Wow! this just got MUCH eaiser!

Now you CAN see.determine EXACTL:Y what a hacked mouse wheel will do
for you (and it might just work)...

You simply need to determine the number of pulses edges per rev (which
depends upon how you are reading the mouse quadrature output (you
won't even need a pc for this app unles you just want to go that way)

Now take the circumference of the wheel that's you're using to do the
feeding of the cordage, and divide that by the number found above.
this gives you yor resolution.

Next you will need to correct for long distance accuracy, which is
simply a correction factor in your software/firmware.

Yes, In THIS case, you probably CAN use an old serial mnouse to get
what you want! (You may/will have "repeating"/Cyclic errors due to the
mouse wheel irregularity (read cheap-ness!<G>) but it sounds like for
what you're doing this will be no problem...

Amazing how the answwers change when the details are known!

Hope this helps,

Ballendo

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "mrclicit" <chris@...> wrote:
>
> 1. How to read a mouse is straightforward:
> http://www.computer-engineering.org/ps2protocol/
>
> 2. I need to measure cordage in lengths from 1 to 100 ft with
> precision of a couple of inches at 100 ft.
>
> If you check around, there is no readily available, simple tool to do
> this. There are the simple counters used by hardware stores and Home
> Depot Electrical Dept's everywhere, but none of these work with
> something similar to a shoe lace or any kind of rope like cord 3/8"
in
> diameter or less....I know the exiting tools don't work because I've
> tried them all (or almost all...)
>
> CL
>