MIDI Controllable Pots

[The Proteus]

Andy,

	Depends. The gray code output encoders would work fine, but some
systems I've designed have used a simple 3-wire pulse encoder feeding into
a uC with an I2C port, then controlling all of my parameters with an
LM1973 connected to whatever I need. Most of what I do isn't
super-accurate, so I can use a solution like this. Others I've seen are
using DACs and SHA arrays to control OTA's, and even just building funky
R-2R ladders into 405x series switches.

Hope this helps,

The Proteus

The Proteus - Morphing the convergence of technology and passion.
-- Musician - Producer - Engineer  -  UNIX Admin Extrordinaire --
"...the best workaround for a bug in a UNIX utility is to install 
 the GNU version" - Kragen Sitaker

On Mon, 18 Oct 1999, Andy Main wrote:

> Hi all,
> 
> Carring on with my ASM1 design, I'm still trying to work out how to
> implement the pots located on the front panel with MIDI control.  My
> guess is to have a knob sending out grey code depending on position,
> link this via logic to a DAC and then control a FET as a voltage
> controlled resistor.
> 
> Has anyone tried to do this before?  Or are there better solutions (I'm
> sure I can't be the only one who has wanted to do this).
> 
> Oh and as for the patch design I've been looking at prices for switches
> and MUXs and have found that Harris do very cheap 4x4 switch arrays
> (less than a pound sterling) with not bad characteristics.  Using an
> fpga I should be able to control a huge battery of these to do what I
> want for a lot cheaper than using a larger switch matrix.  Thanks
> everyone for the input.
> 
> Cheers
> 
> Andy
> 
>