Re: Optical mouse for DRO anyone? - not for WIRE!

Now I don't feel so bad - you are all (well, almost all) missing what
I said about the medium, and coming up with the same ideas my
co-workers offered...now...

Imagine a shoelace, 100 ft long. Wire and flat strapping or webbing is
child's play in comparison - been there, done all that 25 years ago.
Woven cordage changes dimensionally when even the slightest mechanical
pull, push or squeeze is applied. I have put various types of lacing
(polyester, nylon, natural fiber, etc.) through wire measurement
machines with all types of wheels of varying hardness, and they all
performed horribly, losing or gaining as much as 10 inches in ten
feet. The company that makes most of these machines even put together
a custom unit for me that they swore would work, and it did no better.

In theory, the optical mouse should be very accurate if used on a
surface that has consistent chracteristics. On a Windoze PC, it would
be difficult, since the pointer calls to the API do not seem to allow
the low level of control one would expect - as I recall, the
acceleration algorithm is tied to the travel distance in the available
API function. Without being able to compile machine code, acceleration
would be included with distance, hence raw distance throuh a PC would
be an extremely difficult task.

Reading the raw mouse output it seems, would be much easier to do with
a PIC and a simple routine to read asynchronous serial. the velocity
of mouse movement establishes the serial clock, and as long as the
chip is clocked fast enough, distance should be a no-brainer. The
problem I see with this approach is the storage and handling of so
many variables - even if looped every inch.

Time permitting, I'll put something together to try this.