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Remote control support

Using evdev

As long as the evdev module is loaded, a remote that is recogniced as hid device will be treated as a usb keyboard and this means that you can avoid using lirc.

However, many of the keys on your remote may generate keycodes which are not mapped to anything, by default.

In X you can use xev to find the keycodes and xmodmap to map them to useful symbols. Unfortunately, some keys may generate keycodes that X doesn't recognize at all and the device does not support keymaps, or this would be easy to fix.

Using LIRC

Usually remote controls in linux are managed by the lirc software collection.

To get lirc up and running you need to configure some things.

  • Settings for the hardware
    • Where does lirc get its input from? aka. the DEVICE. E.g. /dev/input/event3
    • How to handle the input? aka. the DRIVER. E.g. devinput
  • Settings for mapping driver output generated by your remote (a bunch of hex numbers) to key names (something like 0..9, Volume+, Next, Record)
  • Settings for mapping key presses to actions (usually located in your .lircrc)
Mythubuntu case

On mythubuntu 10.10, you just have to add this line in /etc/udev/rules.d/65-persistent-hauppauge.rules

SUBSYSTEM=="input", KERNEL=="event*", ATTRS{idVendor}=="2040", ATTRS{idProduct}=="8400", SYMLINK+="lirc0"
Device/driver settings

Find the IR receiver's device by looking in the dmesg output for a line similar to:

input: IR-receiver inside an USB DVB receiver as /class/input/input4

Additionally, the IR receiver will be listed if you execute the command:

cat /proc/bus/input/devices

For example:

I: Bus=0003 Vendor=2040 Product=9950 Version=0100
N: Name="IR-receiver inside an USB DVB receiver"
P: Phys=usb-0000:07:01.2-1/ir0
S: Sysfs=/class/input/input4
U: Uniq=
H: Handlers=kbd event4 
B: EV=3
B: KEY=14afc336 284284d00000000 0 480058000 219040000801 9e96c000000000 90020000000ffd

In this example, the remote control gives output into /dev/input/event4.

The event number depends on your particular system and can vary.

Eventually this event number can even vary at every reboot.

You could create a new udev rule in /etc/udev/rules.d/65-persistent-hauppauge.rules.

KERNEL=="event*", ATTRS{name}=="IR-receiver inside an USB DVB receiver", SYMLINK+="input/dvb-ir"

This would make IR receivers handled by the usb_dvb framework always always be linked to /dev/input/dvb-ir.

But Linux systems running recent udev will automatically create non-varying names, a nicer and automatic way of providing a stable input event name:

$ ls -la /dev/input/by-path/
total 0
drwxr-xr-x 2 root root 140 2008-02-07 20:31 .
drwxr-xr-x 4 root root 280 2008-02-07 20:31 ..
lrwxrwxrwx 1 root root   9 2008-02-07 20:31 pci-0000:00:1a.1-usb-0:2:1.0-event-kbd -> ../event1
lrwxrwxrwx 1 root root   9 2008-02-07 20:31 pci-0000:00:1a.1-usb-0:2:1.1-event-mouse -> ../event2
lrwxrwxrwx 1 root root   9 2008-02-07 20:31 pci-0000:00:1a.1-usb-0:2:1.1-mouse -> ../mouse1
lrwxrwxrwx 1 root root   9 2008-02-07 20:31 pci-4-1--event-ir -> ../event4
lrwxrwxrwx 1 root root   9 2008-02-07 20:31 platform-pcspkr-event-spkr -> ../event3

LIRC will use it without needing a special kernel module. use the dev/input (or devinput. Check this with the command "lircd --device=help".) driver and specify the input event device in /etc/lirc/hardware.conf

# /etc/lirc/hardware.conf
# Arguments which will be used when launching lircd

#Don't start lircmd even if there seems to be a good config file

#Try to load appropriate kernel modules

# Run "lircd --driver=help" for a list of supported drivers.
# If DEVICE is set to /dev/lirc and devfs is in use /dev/lirc/0 will be
# automatically used instead

# Default configuration files for your hardware if any

If you have REMOTE and TRANSMITTER sections in your hardware.conf file, they should look like this:

#Chosen Remote Control
REMOTE="Terratec Cinergy DT USB XS Diversity"
#Chosen IR Transmitter
Remote key setup

See device specific section below or try [1].

Sample .lircrc

A sample .lircrc can be found LircrcExample here.