seq2 text

[Michael Potas]

A PLD probably wont solve your problem - it is basicly a programmable array of gates for implementing simlpe logic functions (such as decoding address lines on an ISA bus), replacing a pile of logic on the board.

Just output the mux address from the PIC, and read the ADC.  Using a PLD will only complicate this. 

64 pots in real time is a synch - as with a sequencer, the only pots you care about are the ones which are next to be triggered.  Hence everytime a note is triggered in the sequence, only the next note to be triggered has its value determined.  So if you have a 4x16, you only need to read 4 pots per step (or for 8 x 8, 8 pots) - not a problem!  Most PICS will have no hassles doing this as well as handling MIDI and the rest of it.

Hope I have helped,

Michael

-----Original Message-----
From:	Daniel Gendreau [SMTP:gendreau at frontiernet.net]
Sent:	Wednesday, June 23, 1999 9:32 AM
To:	harry bissell; Synth-DIY
Subject:	RE: seq2 text

> If you have to read (let's say) 64 pots in real time with a
> micro... you will be in
> deep doo-doo...  :^) Harry
Actually, I was thinking about that...

I was working out the design for a PLD that would automatically drive a mux
and an adc to read several pots and store the values into an internal dual
port ram (say 64 bytes).

It would free up the CPU for other things like MIDI I/O, Sequencing, and
other realtime stuff.

It would also be neat to make the opposite device which drives a mux and an
ADC to refresh a S/H array.

Unfortunately, I have only a basic understanding of PLDs...
-Dan G.