close range sensor

please don't multi-post. If you don't know what that means, look it up.
*IF* this question belongs on more than one newsgroup, then you should
cross post it.

Bob

snipped-for-privacy@yahoo.com says...

You didn't mention what type of measurement You prefer: contactless or
contact sensor.
For contact sensors you have variety of mechanical "potentiometer like"
measurements, or optoelectrical(less noisy cause it gives digital
output).
For contactless the only which I know of to be reliable is laser.But for
such short distance it's very expensive.
Ultra sound however is also one choise, but it depends on measuring
environemnt because sound wave is "catches up" all around.

I'm pretty interested how would it work with accelerometer.
This is a cheapest solution.

robert

Problem with laser is how to aim to the target you want trace, you
have to position the target first.


I'll google them.

I did not state that clearly enough.

I think I need some remote sensing device. The host can sense the
target in term of position/speed. The range between the host and the
sensed target is less than half meter. The resulution should be in
term of centimeter. Is that possible? A normal video camera can do the
job, too much information has to exclueded to trace my target. I just
think there should be some cheaper alternative.

Duct tape a mouse to the target?  ;-)


Dave