LIRC (Linux Infrared Remote Control) is an open source package that allows users to receive and send infrared signals with a Linux-based computer system.
1 How LIRC works
You push a button on your remote (lircd.conf), That button is seen by the XBMC translator (Lircmap.xml), XBMC starts the requested command (remote.xml)
Lets trace it backwards.
<play>Play</play> The one in RED is the remote.xml command
<play>KEY_GO</play> is the Lircmap.xml Translated name that points to lircd.conf KEY_GO button
KEY_GO is the actual button name on the remote in lircd.conf
- XBMC performs a command Play (remote.xml)
- The lower case play in the angle brackets is the (Lircmap.xml) translated name
- Then we go to the Lircmap.xml to see what Lirc button holds the value of the lowercase play above.
So we expect to see <play>*******</play> with some value in between the angle brackets.
Whatever value is there is the REAL name of our button on the remote as defined in lircd.conf. Remember, we can map any button to any function. The actual name of the button could be STOP if we wanted to (kinda dumb but it could be) The REAL button name on the remote is NOT required to have anything to logically do with the name of the command you want to perform
Just to illustrate we called it the KEY_GO button
So to sum it up
XBMC sent a command (Remember we are going in reverse) called Play
That Play command is tied to the Lircmap.xml <play></play>
That Lircmap.xml <play></play> is tied to the real button on the remote that is called KEY_GO in lircd.conf
<keymap> <global> <remote> <play>Play</play> </remote> </global> </keymap>
<lircmap> <remote device="My-Remote-Name"> <play>KEY_GO</play> </remote> </lircmap>
begin remote name "My-Remote-Name" bits 5 flags RC6|CONST_LENGTH eps 30 aeps 100 header 2662 836 one 452 429 zero 452 429 pre_data_bits 32 pre_data 0x1BFF83DF gap 106001 toggle_bit_mask 0x8000 rc6_mask 0x100000000 begin codes KEY_GO 0x0F end codes end remote
A custom Lircmap.xml - This file merely defines the translation, bridging a LIRC_button to a XBMC_button. The file is literally named Lircmap.xml and is stored in the userdata directory. Do not confuse the Lircmap.xml with Keyboard.xml.
LIRC_Button - what your lircd.conf calls the physical button on your remote control.
XBMC_button - an XBMC internal button title.
device name - is defined in your lircd.conf file in the "name" field.
This information can be had using the test application "irw" and then hitting some buttons. More on this in the Lirc and Lircmap.xml#Testing Lirc Output section below.
2.1 File format
Lircmap.xml format is as follows:
<lircmap> <remote device="devicename"> <XBMC_button>LIRC_button</XBMC_button> ... </remote> </lircmap>
2.1.1 Device name
The device name is defined in your lircd.conf file in the "name" field. This information can be had using the test application "irw" and then hitting some buttons. More on this in the Lirc and Lircmap.xml#Testing Lirc Output section below.
There are two type of XBMC_buttons in XBMC.
- Predefined Buttons are labelled using their button title such as:
<left> <right> <title> <menu>
- Customized buttons are for people who require more buttons than are defined by default. For example;
<obc1>BUTTON1</obc1> ... <obc254>BUTTON254</obc254>
Note : These obc buttons must be defined in keymap.xml under the [[<universalremote>]] heading
FYI : obc stands for original button code and is a legacy of the old xbox IR remote system
2.2 Testing Lirc Output
use the command 'irw' to test your LIRC configuration
xbmc@xbmclinux:~$ irw 0000000000040004 00 ARROW_UP Cyp_Se_WitheHome 0000000000040004 00 VOLUME_UP Cyp_Se_WitheHome 0000000000040004 00 NUMPAD_6 Cyp_Se_WitheHome 0000000000040004 00 INFO Cyp_Se_WitheHome
In this example Cyp_Se_WitheHome is the device name ARROW_UP, VOLUME_UP, NUMPAD_6, INFO are button names
If you wish to redefine the button names it can be done in /etc/lircd.conf