[sdiy] Magnetic field

[Ian Fritz]

At 08:57 PM 8/1/2004, harrybissell wrote:

>I'd probably go with an optical switch setup... because the "key down" point
>could be
>made totally unambiguous.  If you use a dual phototransistor, or analog 
>sensing
>you could get velocity as well.

The advantage of magnetic is that you don't have to wire up the source.  :-)

The disadvantage is that there is always a lot of variability in response, 
so you need adjustable position.

   Ian