[sdiy] Ensoniq patent, was: distance meter for keyboard, was: Where to get special white keys?

[Rainer Buchty]

On Sun, 1 Mar 2009, cheater cheater wrote:

> Yes, and there are hall effect chip sensors, completely integrated! 
> This is very important, because it simplifies the electronic side of 
> the thing. As you recall Rainer, the SQ80 has lag (now confirmed by 
> me) that has to do with the multiplexing of the scanner. I believe 
> that the chips just output a digital value, which means that every 
> chip has its own dedicated scanner/counter/whatever.

If you're speaking of a modern redesign, I'm fully with you. Today, you 
would probably just use an FPGA to count the individual key oscillators 
rather than multiplexing them to just 4 "pickup lines".

The lag comes IMO from the fact that apart from the multiplexing, these 
lines take a certain time to settle and frequency changes being 
detected.

Rainer