[linux-audio-dev] Knobs, the reply

[Lance Blisters]

> yeah but how?
> i think you'd have to treat them as something other than normal 
> mice for X, afaik it only allows one pointer at a time -
> i.e. multiple mice works fine but they all just control the same 
> pointer.

program against EVDEV, simple input event layer presents events
as byte triplets.

modprobe -ra keydev mousedev; 
modprobe -a evdev
cat /dev/input/event* > my_app

this is how GDAM supports USB touchpads, joysticks, 
keyboards, pen tablets, powermate big knob, etc.   A USB mini 
keyboard, 120+ temporary on buttons for $12, is by far the cheapest
control device.  Treating it as a dedicated device with direct
app support (as opposed to normal keyboard operating hotkeys)
lets the controls stay the same regardless of window focus.

But touchpads generally don't support pressure, so it doesn't
seem to offer anything for drum triggering other than "zero 
travel time" vs. a keyboard.

  -geoff