how_it_works.rst

How it works - technically

Here I would like to describe how the parts are playing together. Additional infos are shown in the installation section.

1. First there is the software LIRC_. It

   • knows about the codes the remote control sends
   • and listens to the IR receiver all the time when started.

   In LIRC's configuration file(s) lircd.conf and/or preferred lircd.conf.d/*.conf there are the used remote control(s) defined.

   Shortened example:

   begin remote
   
     name  Pinnacle_RC1144201
     ...
   
         begin codes
             power                    0x6E2D
             menu                     0x6EE7
             mute                     0x6E1E
             stop                     0x6E2B
             play                     0x6ED1
             pause                    0x6E2C
             ...
   

   You can see the name of the RC and some of the known buttons.

2. LIRC provides - beneath others - a simple program irexec.

   irexec is able to communicate with the above running lircd and gets infos about a pressed button.

   To know what to do with that button info it has a configuration file too: .lircrc.

   That configuration file maps button-presses to actions, for example starting a program.

   In my case I map all buttons to rcmpd - with an appropriate parameter to distinguish them.

   Shortened example:

   begin
       prog   = irexec
       remote = Pinnacle_RC1144201
       button = power
       config = /home/pi/bin/rcmpd power
       repeat = 0
   end
   
   begin
       prog   = irexec
       remote = Pinnacle_RC1144201
       button = pause
       config = /home/pi/bin/rcmpd pause
       repeat = 0
   end
   

   You can see the matching name of the RC(!) and the matching buttons as well.

   So on every button press rcmpd gets called with the appropriate function as parameter.

   That file can be crafted manually or automaticall, described a bit later.

   To get this working irexec needs to run in background and wait for button infos.

3. Finally within rcmpd there is a table or block for every used remote control.

   This is your individual setup - part 1

   Example:

   #*********************************************************************
   # You need to define the choosen keys of your remote controls here!
   #
   # Used for the creation of .lircrc (and as reference for humans...)
   #
   # Need to match the remote's names and the button names from the files
   # /etc/lirc/lircd.conf and/or /etc/lirc/lircd.conf.d/*.conf!
   # Edit the current ones below, add or replace with your own RC(s).
   #*********************************************************************
   
   define_remotes()
   {
     REMOTES=(
   
     [Pinnacle_RC1144201]="
           mute power
           menu tv epg
           a b c d
           vol+ vol-
           pinnacle
           ch+ ch-
           ok
           back loop
           fullscreen
           pause play stop
           ffwd rew
           skip+ skip-
           rec
           1 2 3 4 5 6 7 8 9 0
           cancel
     "
   
     # The definition below uses an "aliasing" feature:
     # If an RC sends a button X but you want rcmpd to behave like button Y
     # then write X=Y
   
     [DENON_RC_126]="
           KEY_POWER
           KEY_VOLUMEDOWN
           KEY_VOLUMEUP
           KEY_CHANNELUP=KEY_NEXT
           KEY_CHANNELDOWN=KEY_PREVIOUS
           KEY_SEARCH=KEY_SCREEN
           KEY_MUTE=KEY_PAUSE
           KEY_MODE=KEY_STOP
     "
   
     )
   }
   

   Later on in rcmpd there is function button_menu()

   That is your individual setup - part 2 - if really needed

   There are the mappings from "button" to internal function where the commands are executed then:

   #-------------------------------------------------------------
   # The assignments of RC buttons to commands in this program.
   # Here you can do your "setup".
   #-------------------------------------------------------------
   
   MUTE|KEY_MUTE)            cmd_mute ;;
   VOL+|KEY_VOLUMEUP)        cmd_volume_up ;;
   VOL-|KEY_VOLUMEDOWN)      cmd_volume_down ;;
   
   PLAY|KEY_PLAY)            cmd_play ;;
   STOP|KEY_STOP)            cmd_stop ;;
   PAUSE|KEY_PAUSE)          cmd_pause ;;
   LOOP|KEY_MEDIA_REPEAT)    cmd_toggle_repeat ;;
   
   SKIP+|KEY_NEXT)           cmd_next_track ;;
   SKIP-|KEY_PREVIOUS)       cmd_previous_track ;;
   0|1|2|3|4|5|6|7|8|9)      cmd_digit $btn ;;
   KEY_0|KEY_1|KEY_2|KEY_3|KEY_4|KEY_5|KEY_6|KEY_7|KEY_8|KEY_9)  cmd_digit $btn ;;
   CH+|KEY_CHANNELUP)        cmd_next_playlist ;;
   CH-|KEY_CHANNELDOWN)      cmd_previous_playlist ;;
   A|B|C|KEY_A|KEY_B|KEY_C)  cmd_ABC $btn ;;
   
   REC|RECORD|KEY_RECORD)    cmd_record ;;
   
   MENU|KEY_MENU)            cmd_toggle_speech ;;
   
   EPG|KEY_EPG)              cmd_info_collection ;;  # of playlists
   D|KEY_D)                  cmd_info_playlist ;;    # current playlist
   BACK|KEY_BACK)            cmd_info_station ;;     # respective "album"
   FULLSCREEN|KEY_SCREEN)    cmd_info_track ;;
   PINNACLE)                 cmd_info_state ;;
   TV|KEY_TV)                cmd_info_time ;;
   
   POWER|KEY_POWER)          cmd_poweroff ;;
   #-------------------------------------------------------------