Configuring external rotatory volume knob

[felipegules]

I've bought an external USB Rotatory volume knob but it hasn't worked out of the box with rAudio. So I've configured it using xbindkeys and Xmodmap.

1. Install Xmodmap and xbindkeys
   sudo pacman -S xorg-xmodmap xbindkeys

2. Add these lines on your ~/.xbindkeys file:

# Increase volume
"amixer set PCM 3%+"
   XF86AudioRaiseVolume

# Decrease volume
"amixer set PCM 3%-"
   XF86AudioLowerVolume

# Mute volume
"amixer set PCM toggle"
   XF86AudioMute

3. Add on ~/.Xmodmap

keycode 114 = XF86AudioLowerVolume
keycode 115 = XF86AudioRaiseVolume

4. Add on /etc/X11/xinit/xinitrc

xbindkeys
[[ -f ~/.Xmodmap ]] && xmodmap ~/.Xmodmap

Note that after a rAudio update, the xinitrc file is overwritten, so you have to redo the step 3 (or maybe automate-it creating a cron rule @reboot?)

Notes:
I've got the keycodes using xorg-xev
DISPLAY=:0 xev
or
xev --display localhost:0.0 -1 (I don't remember)