RE: [CAD_CAM_EDM_DRO] Re: Optical mouse for DRO anyone?

> It would seem to me that optical mice are not being used by
> many folks, especially not by us on this list.
>
> I understand the economics of inexpensive options, but what
> if one needs to measure position on a 50 ft. long axis? What
> if other limitations prohibit use of a wheel or ball?
>
> I have read the IEEE standard for PC mouse output, and the
> routine needed to read one is actually pretty simple without
> a PC (it's a serious API programming task to do so on a PC).
> Optical mice at the cable end (or even wireless receiver end)
> are no different.
>
> When I get some more free time, I'll post the links I started
> with, and if I start to design & build something, I'll do the
> same - if anyone is interested.
>
> C

Ok, now you're getting vague.

To the question - "can I run a mouse up and down a surface to measure things
with it" - the answer is 'Why, yes you can".

Now to vague.

What accuracy?
What resolution?
What reliability?
What speeds are involved?

Trying to measure a mill table to 0.001" over 6 inches is different to
measuring over a 50 foot length. Measuring the size of molecules is
different again. What exactly are you trying to measure?

Look at those 'wheel on the end of stick' things they use to mark out
playing fields or measure fields. Not as accurate as surveying gear
(infrared beams or lasers, similar to how radar guns work), but good enough.
The way they work is exactly how ball mice work.

Years ago I got involved with a telescope being swung around, and trying to
determine its position. We gave them a bunch of bar codes & a scanner, they
stuck the bar codes on the wall and determined its position by the last one
scanned. Not exactly high accuracy, but good enough for them. Larger sizes
require different methods.

Yes, you can stick bar codes on your mill table to determine positioning,
but you may be unhappy

Even elevators do a similar thing to determine what floor they're at (&
where the floor is), rather than try to measure how much cable has been
played out. Occasionally you'll see when the elevator overshoots the floor
a small bit (like 20mm), and as the doors open it will be slowing moving to
get the floors lined up. Getting people moving (and complaining less) takes
precendence over accuracy.

As to mice, when you are taking about the mouse output being easy to read, I
assume that means serial (RS232). USB (without a PC) is much harder, mainly
due to the lack of a hobbyist-friendy USB host chip. You can buy USB chips,
but they are to make devices that plug into the PC, not having something
plugged into them.

With a PC may be easier, see Microsoft multipoint, which lets you use
multiple mice on a single PC.

I doubt you could buy a serial optical mouse these days, they went USB a
long time ago. As previous messages pointed out, you'll have better luck
hacking a serial ball mouse.

Tony