Das Komputermaschine Ist Fur Der Gefingerpoken

A good friend of mine recently tossed me some computer parts, including an HP illuminated multimedia USB keyboard (model SK-2565, part no. 5185-2027). Since I had been looking to replace my old keyboard (a $10 PS/2 job that I turned into a k-rad all-black cowboy deck with blank keys), and had been suffering from an inability to control my PCM volume or music from the keyboard without launching alsamixer or mocp respectively, a particularly acute problem when playing StarCraft, I found herein an opportunity.

HP SK-2565 USB Keyboard

This keyboard has nineteen buttons and one knob across the top. In order, they are (or look like) sleep, help, HP, printer, camera, shopping, sports, finance, web (connect), search, chat, e-mail, the five standard audio buttons (stop, previous, play/pause, next, load), a volume knob, mute, and music. Since the keyboard was furry enough to qualify as a mammal upon receipt, the first thing I did was clean it, a process which spanned several hours (though the process was niced down somewhat). The previous two sentences are related: the top buttons also happen to be built in such a way as to require utterly complete disassembly of the keyboard to remove and replace, and I am ashamed but not at all surprised to say I got the replacing part wrong. The play/pause button is now swapped with the previous button. And I am totally not taking this thing apart again any time soon.

But it is for the best! After figuring out sometime later that I had goofed, I decided (Daniel Gilbert, this one’s for you) that I liked it better this way anyway. Which is perfectly fine, of course, since I’m about to get to the good part: how I made my HP illuminated multimedia USB keyboard special upper buttons work in Linux, using Xmodmap, and in awesome, using rc.lua.

Turns out it’s extremely easy to bind arbitrary keycodes to keysyms (a full list of which can be found in /usr/share/X11/XKeysymDB), at least using GDM. By default (on Gentoo), GDM loads /etc/X11/Xmodmap, as specified by the sysmodmap setting in /etc/X11/gdm/Init/Default. Mine now looks like this:

keycode 223 = XF86Sleep
keycode 197 = XF86Shop
keycode 196 = XF86LightBulb
keycode 195 = XF86Finance
keycode 194 = XF86WWW
keycode 229 = XF86Search
keycode 121 = XF86Community
keycode 120 = XF86Mail
keycode 144 = XF86AudioPlay
keycode 164 = XF86AudioStop
keycode 160 = XF86AudioMute
keycode 162 = XF86AudioPrev
keycode 153 = XF86AudioNext
keycode 176 = XF86AudioRaiseVolume
keycode 174 = XF86AudioLowerVolume
keycode 118 = XF86Music

And now, the answers to all your questions:

  1. I figured the keycodes out by running xev and banging on the buttons.
  2. XF86LightBulb is the closest thing I could find to “sports” that wasn’t already taken.
  3. The volume knob “clicks” and sends a keycode 176 or 174 depending on the turn direction.
  4. I did not map help, HP, printer, or camera because they do not appear to generate keycodes.
  5. I did not map audio load because I forgot. I will do it when I can think of an action to bind it to.

The next step was to make these keys actually do something in my window manager. Bindings are pretty easy to make in /etc/xdg/awesome/rc.lua. Without getting into too much detail, I bound keys to things. I am particularly impressed with how I can control audio via amixer, and my MOC playlist via commands without even having the interface open. Another bonus is the sleep button running xlock. Here’s a sample line:

key({ }, "XF86LightBulb", function () awful.util.spawn("starcraft") end),

A particularly nice one is the search button, which runs the following script (be nice, my bash-fu is rusty):

#!/bin/bash
Q=`zenity --entry --width 600 --title="Google Search" --text="Google search query:"`
if [[ "$Q" != "" ]]; then
    EQ=`echo $Q | sed s/\ /\%20/g`
    firefox http://www.google.ca/search?q=$EQ
fi

I frequently say that if I took one thing home from working in the automotive sector, it was Kaizen.

Apr 4th, 2009
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