[sdiy] Piezo keyboard

[Peter Grenader]

john mahoney wrote:

> I don't know if the anodizing has to be removed or not -- is it an
> insulator? Since it's a natural color you wouldn't see much difference
> either way. However: Bare aluminum gets covered by a thin, black oxide that
> isn't very visible -- until it's all over your fingers. Yuck!

Yeah, I don't know.  When I mentioned that in my last post I was thinking
"am I full of it right now?' when I was typing it.  Because you're right -
aluminum being a passive metal, the oxidation layer happens anyway just by
it being in contact with air. The anodize is nothing more than a tinted
layer of induced oxidation that takes the place of the one that would occur
naturally. so possibly the anodize would be OK.

But what just came to me,  which would be WAY cool:

What if the capacitance thing worked - THEN I could have two functions per
key.  One with light pressure and a second when you pressed a bit.  Like
upper and lower case. This would be really interesting if you ask me.  Two
voltage pots per key.  hmmmmmm....

OK, look -I've done a touch key response circuit which passes a high when
it's touched.  Currently it's connected to a quarter.  If it still works
(been in the pile for some time, you know how that goes) I'll try it with
these switches and see. I'll get back to ya all.