LIRC

関連記事

• LIRC Device Examples

この記事ではシリアル・USB 赤外線デバイスを使って LIRC "Linux Infrared Remote Control" を設定・使用する方法を説明しています。

概要

LIRC はサポートしているリモコンのキーが押されたのをプログラムにあわせてコマンドに変換することができるデーモンです。ここで、「プログラムにあわせて」とは実行しているプログラムによってキーの押下で異なる動作をさせることができることを意味します。

LIRC の役割

LIRC を使ってリモコンからの情報がプログラムに流れる過程は以下の通りです:

• ユーザーがリモコンのボタンを押すことで IR または RF 信号が送信されます。
• 信号が Linux が入ったパソコンに接続されたレシーバーによって受信されます。
• カーネル (の適切なモジュール) は /dev/lirc0 でレシーバーからのパルス幅の情報をキャラクタライズします。
• /usr/bin/lircd は /etc/lirc/lircd.conf からの情報でパルス幅をボタンの押下情報に変換します。
• LIRC を使用するプログラムは /usr/bin/lircd のボタン押下情報を ~/.lircrc によってユーザーが定義した操作に解釈します。

必要なファイル

• /etc/lirc/lircd.conf - スキャンコード --> キーに変換するシステムレベルの設定。システムの各リモートコントローラ・レシーバー固有で、必要ならば複数のリモコン・レシーバの設定を記述することもできる。
• ~/.lircrc - プログラムごとの lirc マップ (~/.lirc/foo, ~/.lirc/bar など) を指定する include ステートメントを記述するファイル。
• ~/.lirc/foo - キー --> 操作に翻訳するユーザーレベルの設定。各リモコンとアプリケーション foo の固有設定。

インストール

公式リポジトリにある lirc-utils パッケージをインストールします。ほとんどの LIRC カーネルドライバーは既にメインラインのカーネルに入っています。ハードウェアが lirc_wpc8769l モジュールを必要とする場合は、lirc パッケージだけをインストールしてください。

設定

リモコンによっては LIRC がなくても"キーボード"として認識されそのように動作することがあります。このように認識されているとコマンドを二重に実行してしまう可能性があります。シェルやテキストエディタを開いて、リモコンのボタンを押してキーボードとして認識されていないかテストして下さい。文字や数字が打ち込まれたり、物理キーボードの上・下・右・左矢印キーのように動く場合、無効にする必要があります。次に進む前に #リモコンがキーボードとして機能する を見て下さい。

LIRC の設定ファイル

Defining /etc/lirc/lircd.conf which is specific to each remote/IR receiver is the first step in setting up a remote.

ノート: Common configs are provided by lirc-utils, like those bundled with TV cards that can be installed automatically. The primary source of config files is the LIRC homepage. Check the official list of supported hardware to know, which LIRC kernel modules and lircd driver required.

規定の設定ファイルを使う

Identify which remote/receiver is to be used and see if /usr/share/lirc contains a pre-built config file for it. Once identified, create/edit /etc/lirc/lircd.conf to use an include statement that points to the selected one.

Example:

/etc/lirc/lircd.conf

 include "/usr/share/lirc/streamzap/lircd.conf.streamzap"

設定ファイルを作成する

Users with unsupported hardware will need to either find a config file someone else has created (i.e. google) or create one. Creating one is fairly straightforward using the included /usr/bin/irrecord program which guides users along the needed process. If using a detected remote, invoke it like so:

irrecord --device=/dev/lirc0 MyRemote

The program will ask users to begin hitting keys on the remote in an attempt to learn it. If all goes well, the user will be prompted to map out each key press to a specific scancode LIRC uses to identify that specific key press. The process should take no more than 10 minutes. When finished, save the resulting file to /etc/lirc/lircd.conf and proceed.

ノート: Consider sending the finished config file to the email address mentioned in the program so it can be made available to others.

リモコンのテスト

LIRC デーモンを起動:

# systemctl start lirc

/usr/bin/irw を使ってリモコンをテストしてください、リモコンのボタンを押した時に LIRC が受信したものを全て標準出力に流します。

例:

$ irw
000000037ff07bfe 00 One mceusb
000000037ff07bfd 00 Two mceusb
000000037ff07bfd 01 Two mceusb
000000037ff07bf2 00 Home mceusb
000000037ff07bf2 01 Home mceusb

プログラムごとの設定

LIRC has the ability to allow for different programs to use the same keypress and result in unique commands. In other words, mplayer and vlc can respond differently to a given key press.

Decide which programs are to use LIRC commands. Common programs include: mplayer, mythtv, totem, vlc, and kodi.

ノート: Kodi implements LIRC in a non-standard way. Users must edit ~/.xbmc/userdata/Lircmap.xml which is a unique xml file, rather than the LIRC standard files the rest of the programs use. Interested users should consult the Kodi#Using a remote controller article.

Users should create the expected files showing LIRC where the various program-specific maps reside:

$ mkdir ~/.lirc
$ touch ~/.lircrc

• Populate ~/.lirc with the program specific config files named for each program.

Example:

$ ls ~/.lirc
mplayer
mythtv
vlc

ノート: Providing an exhaustive listing of keymaps for each program is beyond the scope of this wiki article. Many pre-made files unique to each remote/program are available via googling.

• Edit ~/.lircrc to contain an include statement pointing to ~/.lirc/foo and repeat for each program that is to be controlled by LIRC.

Example:

~/.lircrc

include "~/.lirc/mplayer"
include "~/.lirc/mythtv"
include "~/.lirc/vlc"

トラブルシューティング

リモコンがキーボードとして機能する

Xorg detects some remotes, such as the Streamzap USB PC Remote, as a Human Interface Device (HID) which means some or all of the keys will show up as key strokes as if entered from the physical keyboard. This behavior will present problems if LIRC is to be used to manage the device. To disable, create the following file and restart X:

/etc/X11/xorg.conf.d/90-streamzap.conf

Section "InputClass"
  Identifier "Ignore Streamzap IR"
  MatchProduct "Streamzap"
  MatchIsKeyboard "true"
  Option "Ignore" "true"
EndSection

Don't forget to alter the MatchProduct property according to one shown in Name from output of

$ cat /proc/bus/input/devices | grep -e IR

For example WinFast for N: Name="cx88 IR (WinFast DTV2000 H rev."

Legacy Info Which Needs to be Modernized and Vetted for Accuracy

Setup a HID device with LIRC

Some remotes are supported in the kernel where they are treated as a keyboard and mouse. Every button on the device is recognized as keyboard or mouse events which can be used even without LIRC. LIRC can still be used with these devices to gain greater control over the events raised and integrate with programs that expect a LIRC remote rather than a keyboard. As drivers are migrated to the kernel, devices which use to only be useable through LIRC with their own lirc.conf files become standard HID devices.

Some HID remotes actually simulate a USB infrared keyboard and mouse. These remotes show up as two devices so you need to add two LIRC devices to lircd.conf.

First we need the /dev/input device for our remote:

 $ ls /sys/class/rc/rc0

One of the files should be input#, where the number matches the event# of the device. (To clarify you can check that directory, it will have an event# file.

ノート: If you have more than one ir device then there may be multiple directories under /sys/class/rc. Under event# cat name to verify which device you are looking at.

then go to /dev/input/by-id

 $ ls -l /dev/input/by-id

You should find a file that symlinks to the input# above, and possibly others with a similar names for mouse events.

 lrwxrwxrwx 1 root root  9 10月 14 06:43 usb-3353_3713-event-if00 -> ../event9
 lrwxrwxrwx 1 root root 10 10月 14 06:43 usb-3353_3713-event-if01 -> ../event10

Here 'usb-3353_3713-event-if00' and 'usb-3353_3713-event-if01' are the Linux input device event for our HID device, one for the keyboard, another for the mouse.

Then, we need to edit /etc/conf.d/lircd.conf. This file contains the parameters for LIRC daemon

 #
 #Parameters for daemon
 #
 
 LIRC_DEVICE="/dev/input/by-id/usb-3353_3713-event-if00"
 LIRC_DRIVER="devinput"
 LIRC_EXTRAOPS=""
 LIRC_CONFIGFILE="/etc/lirc/lircd.conf"

ノート: Here we set up a LIRC device with the id 3353_3713, you should replace it with your own device input event name, whatever it is.

The latest version of the config file for HID remotes exists in the LIRC git repository [1]. Simply save it as /etc/lirc/lircd.conf.

In order to launch the LIRC daemon for HID remote, You must enable evdev module first

# modprobe evdev

ノート: LIRC 0.8.6 has changed the default socket location from /dev/lircd to /var/run/lirc/lircd, but many applications still look for the socket in the old location. Since lirc-utils 0.8.6-3 the /etc/rc.d/lircd script creates a symlink from /dev/lircd to the /var/run/lirc/lircd socket when it starts the lircd daemon and removes the link when the daemon is stopped.

Serial receivers that depend on lirc_serial

Make sure that your serial port is activated in the BIOS. There you can also set and lookup I/O address and IRQ settings of your ports.

Now there might be a problem: the module lirc_serial is build to use ttyS0 (COM1), if your device is not connected to ttyS0, you will have to either change the module-options or rebuild the LIRC module. If your device is connected to ttyS0, you can skip this step

To change the options for the lirc_serial module, you edit /etc/modprobe.d/modprobe.conf and add this line:

options lirc_serial io=0x2f8 irq=3

You should change the values after io and irq to reflect you serial port settings, the values above may work for you if you are using ttyS1 (COM2) to connect your IR-device. But you will find the correct values by checking dmesg:

$ dmesg | grep ttyS

Building the lirc_serial module for another ttySx

Update abs

# abs

Copy the LIRC files to a directory you choose yourself:

$ cp /var/abs/extra/system/lirc /some/dir

$ cd /some/dir

Edit the PKGBUILD in that directory.

Replace the line:

./configure --enable-sandboxed --prefix=/usr \
    --with-driver=all \\
    return 1[/code]

with:

./configure --enable-sandboxed --prefix=/usr \
    --with-driver=com2 \
    || return 1[/code]

Where you replace com2 with the com-port you need.

Build and install the package:

$ makepkg
# pacman -U lirc-version.pkg.tar.gz

Loading

Now try to load the serial module:

# modprobe lirc_serial

If this produces an error which says your serial port is not ready, you have the problem that your serial port support is build into the kernel and not as a module (in the default arch kernel it is build into the kernel)

If it is built into the kernel you will have to do the following (remember that it is built into the kernel, you will need to make some changes later too)

You will have to release the serial port:

# setserial /dev/ttySx uart none

(Replace x with your port number)

Load the module again:

# modprobe lirc_serial

Now it should not show any errors, and the modules lirc_serial should be listed in lsmod

Checking module based receivers

NOTE: This section only applies if your device requires a lirc_[driver] kernel module.

Before you start using lirc, you should check if your receiver is working, and if there is IR interference. Possible sources of interference include monitors/televisions (especially plasma displays), fluorescent lamps and direct or ambient sunlight. Start the following command to display raw receiver input.

# mode2 -d /dev/lirc0 

If you press buttons on any IR remote, you should see a series of pulses and spaces. If there is very frequent output without pressing buttons on your remote, your receiver suffers from interference. You want to avoid such interference, e.g. by placing the receiver behind or under your plasma tv.

If you can't make out where the interference is coming from, you can try to put a cardboard roll right in front of the receiving diode, so that it only gets light from a specific direction. Invoke mode2 as above. Then point at different locations till you receive IR noise.

参照

• MythTV Wiki:Remotes article
• サポートしているハードウェアの公式リスト