[sdiy] Make a CS80

[Colin f]

> I've been wondering about Quantum Tunnelling Compound for 
> polyphonic aftertouch.

Me too.
 
> You'd mount a small pill of QTC under each key, sat on top of 
> a PCB with 'fingers' etched on it. A microcontroller could 
> then read the resistances of all the pills and report back to 
> the voices. It's fairly strightforward, but I haven't tried it yet.

I was thinking of replacing one of the conductive pads in the typical rubber
domed contacts you find in a keyboard with a QTC pad.
Then you already have the PCB fingers, and a matrix to scan.
Potentially you could differentiate the resistance drop on a single QTC
contact to capture the velocity, thereby needing only one contact.

Cheers,
Colin f