[sdiy] Rotary encoders...

[Grant Richter]

A really clever solution to the old problem of using real time knobs with
stored presets
(the knobs will never be pointing at the preset numbers).

The many solutions to this problem which have been tried would make a rather
long article themselves. The Poly-6, OB-8 and Prophecy each have a different
algorithm for dealing with the difference between the stored value and real
time knob position.

It looks like Clavia finally found a good solution, programmable knob
"pointers". Very elegant, but a major increase in the panel processor I/O
burden.

My guess is the LEDs have to be networkable with a serial protocol. Perhaps
I2C port expanders at each encoder for the ring of LEDs. I count 15 LEDs per
encoder, that would fit with existing 16 pin expanders. I wonder what the
16th pin is being used for? Perhaps color control?

Of course each encoder/LED group could have PIC for itself, there would be
advantages to having each control have it's own intelligence. Networking and
low latency updating (transmit on knob movement) come to mind.

From: Peter Grenader <peter at buzzclick-music.com>
Date: Tue, 17 Feb 2004 10:11:40 -0800
To: <synth-diy at dropmix.xs4all.nl>
Subject: [sdiy] Rotary encoders...


Kids - 

Ever notice those kewwwwwwwl LEDs around the encoders used in the Nord lead
3?

http://www.clavia.se/pictures/nordlead3/NL3knobturnLarge.jpg

Did Nord make that sub assembly or are those stock encoders which are made
with the led bezel?  I dunno, sure looks like they are stock.  But whose?

Anyone?

Anyone? 


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