[linux-audio-dev] Knobs, the reply

[Lance Blisters]

On Thu, Jun 10, 2004 at 08:42:42PM -0400, Dave Robillard wrote:
> Speaking of touchpads, does anyone know of a (usb) touchpad that works
> with your finger, not just a pen?  (The only ones I've seen just work
> with the stylus, which is no good)
> 
> I want to get one and set it up as a MIDI controller, like a poor mans
> Kaoss Pad (and what I think would be the ultimate expressive MIDI
> controller).
> 
> Surely one of these things must exist?

  Most (all?) by default work only in relative motion mode, 
not absolute motion mode.  So moving your finger a bit to the left
sends -5 -7 -2  but you have no idea of where on the pad your
finger is.  In fact, the relative events don't even add up; move
back and forth a from side to side a dozen times, the values tend
do drift in some direction (the direct USB events, pre-mouse
accelleration)  So, it doesn't map onto the kaoss pad very well.
I have an "easy-cat" usb touchpad.  IIRC it has an absolute mode
under windows, but i've seen no linux code to enable it.  They
wanted me to sign an NDA for futher info.  However, this device
is still usable for x-y parameter control, just only via relative
motions.  There are some binding files to support this device in
GDAM's CVS repository.

  -geoff