On 16 Sep 2003 11:54:21 -0700, (Ben Nguyen) wrote:

Thanks for the great ideas! Incidentally, this is for my senior
project in engineering technology at ucsd. I graduate
in June 04, so thats the timeframe Im working with.

I was looking at my computer mouse, and that seems to do something similar.
What if I use the rolling mechanism that the ball turns and its circuit
board to make a digital caliper?

Even better if I could replace the circuit board completely with something
homebrew!

Thanks!

Ben:

You might take a look at
http://www.capsense.com/capsense-wp.pdf

It will give you several ideas on capacitive sensors for measuring
displacement if you decide to build digital calipers.

One design mentioned can yield 0.0002 accuracy over 6" with standard
PCB fabrication of the sensor.


Jack