I listen to Pandora all the time at home, and I often want to control it without using the keyboard or mouse. So, a few years ago I bought a USB infrared receiver for $14. Of course, since I use Linux, the hidden cost was hours and hours of time figuring out how to set it up. I never wrote anything down back then, but since I had to relearn it all last weekend to make a few changes, now is a good time to document it.
This article is written for Ubuntu 13.04, so some things might be different for other operating systems. It also assumes you want to use an infrared remote; you could also use a bluetooth remote or some cellphone app, but I don’t know anything about those.
irrecordand follow the instructions to generate a remote definition file.
/etc/lirc/to use the new remote definition file.
/etc/lirc/lircrc, or (b) configure
~/.lircrcand set up
irexecto start at session startup.
First, you need an IR receiver. The safest bet is to buy a “USB Media Center IR receiver,” aka an “MCE receiver.” I got the following one for $14, including shipping:
Note that IrDA ports found in older laptops won’t work for this purpose.
Second, you need an IR remote. You could use an existing remote if you know it won’t cause a conflict—say, you no longer use the TV it goes with, or the TV and the computer are in different rooms. Or, you could buy a new remote just for the computer. But the most likely option is that you have an existing remote that has a “universal” feature. In that case, all you need to do is configure the universal feature to use some non-existent device. For example, if your TV remote can control a DVD player, and you don’t have DVD player, configure the remote to control any DVD player listed in the remote’s manual. It doesn’t matter which one—LIRC can (probably) handle any.
If you have a Windows Media Center (MCE) remote (as opposed to, say, a TV or DVD remote), or if you have set up your universal remote to send MCE codes, then X will automatically interpret some buttons as keyboard keys. If this is all you want, then you’re done!
Unfortunately, most people will want more than this, in which case the built-in keyboard emulation will just get in the way. So, you need to disable it. If you forget to do so, X will send the keyboard keys in addition to whatever you configure LIRC to do, and it will appear that you’re getting double key presses.
First, you need to determine the product name for your IR receiver. To do
this, make sure your IR receiver is plugged in and look through
/proc/bus/input/devices to find the name of your device. Here’s the output
on my computer:
$ grep '^N:' /proc/bus/input/devices N: Name="Power Button" N: Name="Power Button" N: Name="Microsoft Comfort Curve Keyboard 2000" N: Name="Microsoft Comfort Curve Keyboard 2000" N: Name="Logitech Unifying Device. Wireless PID:101b" N: Name="Media Center Ed. eHome Infrared Remote Transceiver (1934:5168)" N: Name="MCE IR Keyboard/Mouse (mceusb)"
Find the one that sounds like “Media Center … Remote Transceiver.” Then,
create the file
the following contents, replacing the value of
MatchProduct with whatever
name you found above. (In the old days, we would have added this to
/etc/X11/xorg.conf, but now evidently we create these xorg.conf.d files.)
# Disable the MCE remote from acting like a keyboard. (We use lirc instead.) Section "InputClass" Identifier "MCE USB Keyboard mimic blacklist" Driver "mceusb" MatchProduct "Media Center Ed. eHome Infrared Remote Transceiver (1934:5168)" Option "Ignore" "on" EndSection
LIRC is the program that interprets IR signals. To install it, run:
$ sudo apt-get install lirc lirc-x
LIRC works in two steps: the
lircd program that translates remote signals to
generic “buttons,” and then client programs—notably
buttons to actions.
So, three are things you need to do:
1. Create a remote definition file, unless one already exists.
lircd to use the proper definition file.
If you’re using a non-MCE receiver, you may also have to spend some time configuring LIRC to use your receiver, but thankfully MCE receivers work out of the box.
Unless there already happens to be a file in
works with your remote, you are going to have to train LIRC to understand all
the buttons on your remote. (If there is one already, skip to the next
Make sure that
lircd is not already running, and then use the
program to create what I am calling a remote definition file. Obviously,
WHATEVER_YOU_WANT with, well, whatever you want to call your remote.
$ sudo service lirc stop $ sudo irrecord --device=/dev/lirc0 /etc/lirc/lircd.WHATEVER_YOU_WANT.conf
Follow the on-screen instructions, and when it when it asks you to “Please enter the name for the next button,” open up a new terminal window and run
$ irrecord --list | less
to find an appropriate name for the button you want to learn. I recommend only programming four or five buttons for now, and then moving on to the next section. I ended up having to delete my config and start over several times, so it’s not worth investing too much time now.
Once you have tested your config with
irw in the next section and are
confident it is working, you can run the same
irrecord command again to add
more buttons. As long as you point it to the same config file, you won’t have
to go through the training step again.
Now we have to tell
lircd to use the new definition file. We do this in two
include your remote definition file. This
will be the only command in the file.
REMOTE_LIRCD_CONF to the remote
definition file. (I don’t think this does anything, but it doesn’t hurt.)
lircd and test it with
irw. Press a few of the buttons you
have trained in the previous section and make sure they show up in
$ sudo service lirc start $ irw 000000037ff07bed 00 KEY_CHANNELUP mce_custom 000000037ff07bec 00 KEY_CHANNELDOWN mce_custom
If you get one line per press (plus repeated lines if you hold down the button), it works! Feel free to go back to the previous section and configure more buttons.
The last step is to configure
irexec, which is the thing that actually does
something useful when you press a button. You have two choices here:
/etc/lirc/lircrc and have
irexec run as root. This has the
advantage of starting and stopping
irexec automatically whenever you
~/.lircrc and have
irexec runs as your user. If you do this,
you need to configure your desktop environment to automatically start
irexec at the beginning of each session. You will also need to restart
irexec every time
Create one of the two files listed above. The documentation is pretty good, but here is my config file for reference:
begin button = KEY_VOLUMEUP prog = irexec config = /usr/bin/pactl -- set-sink-volume 0 +2% # vol+ repeat = 1 end begin button = KEY_VOLUMEDOWN prog = irexec config = /usr/bin/pactl -- set-sink-volume 0 -2% # vol- repeat = 1 end begin button = KEY_PLAY prog = irexec config = /home/mark/local/bin/pithos-control play end begin button = KEY_PAUSE prog = irexec config = /home/mark/local/bin/pithos-control pause end begin button = KEY_STOP prog = irexec config = /home/mark/local/bin/pithos-control pause end begin button = KEY_FASTFORWARD prog = irexec config = /home/mark/local/bin/pithos-control skip end begin button = KEY_SLEEP prog = irexec config = /usr/bin/xset dpms force off # blank monitor end
The file is pretty self-explanatory. Each
button is something I defined in
my remote definition file. The
pactl program works with PulseAudio, which
is the default audio system on Ubuntu. The
pithos-control program is
described in the next section. And the
xset line turns off my monitor,
which I often want to do if I’m listening to music.
When you’re done, remember to either
sudo service lirc restart if you are
irexec -d if you are using
Otherwise, nothing will happen when you press a button.
I always use Pithos to play Pandora. Not only is it way lighter than the bloated web-based one, it is also controllable via D-Bus. Sending D-Bus commands manually is a bit ugly, so I made a little wrapped called pithos-control. The main advantage is that it adds discrete play and pause commands, which Pithos lacks.
When I was trying to set up my remote, I found plenty of suggestions on the
Internet to use something called
ir-keytable instead of, or in conjunction
with, LIRC. I did use it for a while, but in the end I found that using
straight LIRC was way better.
The main problem was that
ir-keytable (by itself) creates virtual keyboard
presses for each button press. If you want to control, say, the volume, you
would configure the “Vol-“ button to send the XF86AudioLowerVolume key. This
sounds fine, but the issue is that, at least in XFCE, the media keys cause the
foreground window to lose focus each time they are pressed. So, if I were
typing something and my wife hit the volume button, a few of my keystrokes
would be lost, which was really irritating. It was even worse when I was
playing a game.
I put up with the above for a long time, but the final straw was when I tried
to get the
xset dpms force off command to work. It was impossible with
ir-keytable because the virtual keyboard button that I had to map the
command to would immediately wake the monitor up. This ended up being a
blessing in disguise, since it made me realize that I could ditch
ir-keytable for LIRC.
I also found that
ir-keytable was less reliable than LIRC. I have no hard
evidence of this and I am not inclined to set it up again, but that was my