[sdiy] Magnetic field

[Ian Fritz]

At 08:53 PM 8/2/2004, harrybissell wrote:

>LOL !!! Hah I still agree with me.
>
>If you are using the photosensors as analog circuits it would be very 
>difficult
>to set up, however
>I think slotted optical switches with keyboard activated "vanes" is the way to
>go.  Key trip point
>can be precisely set mechanically, there is no possibility of adjacent key
>interference.  I'd sense
>velocity by the time-of-flight of the vane from one sensor to the next... 
>there
>were sensors with
>dual photoconductors at one time.
>
>I don't think temperature dependancy is an issue at all in digital 
>sensing, nor
>is LED life, aging
>etc.  Its not like we're gonna stick it in our mouth or anything (like Ian 
>does
>!!!)   :^P

ROFL!  Sure, if you are just going to do digital then any old thing will 
do.  (Still less circuitry with magnetic, though.)  But there was also a 
suggestion of doing per-key aftertouch (don't ask me why).  Once you get 
into analog, optical has lots of gotchas.

   Ian