Next Previous Contents

## 8. Setting up a remote control.

MythTV does not have native remote control receiver and decoder software built-in. Instead, remote control functions are implemented by cooperating with lirc, the Linux Infrared Remote Control program. lirc handles the IR hardware and passes keystrokes to MythTV, which then acts as if the user had pressed the keys on the keyboard. The file `keys.txt` describes the keys used to control MythTV.

NOTE: If you are running Mandriva, you may install lirc by executing: `# urpmi lirc lirc-remotes` and bypass the manual compilation steps described below by jumping to the <@@ref>completing_lirc_installCompleting the lirc install section. See the contrib/mandrake91.etc.sysconfig.lircd file for an example of how to configure lircd.

Some IR devices require a kernel recompile, and some don't. However, all at least require having the kernel source available as a resource for the lirc build process.

## 8.1 Gentoo

To install lirc on Gentoo, all you need to do is:

> `

>     # emerge lirc

> `

The third option is to dispense with lirc altogether by purchasing an IR keyboard (various options exist, although Chicony appears to work for some people) and a learning remote control. The IR keyboard receiver plugs into the PS/2 keyboard port on your PC and you would train your learning remote to emulate the various keystrokes from `keys.txt` of your IR keyboard. Using this method removes lirc entirely from the picture - your remote will be sending keypresses that your PC "sees" on the keyboard port.

pulses may correlate to "Channel Up". The `lircd.conf` file will then contain a line that looks something like this:

> `

>               ChannelUp                0x0000000000001020

> `

The `lircd.conf` file can have multiple remote controls defined.

The second file is `lircrc`, which takes the name of the button which was pressed ("ChannelUp") in the above example, and correlates that to an action to be performed by a program using the remote control. So in MythTV, ChannelUp means one thing, while in mplayer it means something different. `lircrc` gives you the flexibility of taking the name of the button and having it perform different actions depending on which program you're using at the time.

NOTE: The definitions in `lircd.conf` come from the user community, and there is no standard for the common button names. One `lircd.conf` file may contain a definition for a button called "ChannelUp", while another may contain a definition for "Chan+". Your `lircrc` file must therefore be configured appropriately, or it won't work.

If this fails, complaining of a missing `lircd.conf` file, then you must find or make one. First look for a pre-made configuration file at http://lirc.sourceforge.net/remotes/. Mandriva 9.1 users, look in `/usr/share/lirc-remotes`. If you find one your remotes either on the website or in `/usr/share`, download or copy the file, name it `lircd.conf` and put it in your `/etc` directory. If you couldn't find your remote, you must make your own `lircd.conf` file.

To make your own `lircd.conf` file

> `

>     $ irrecord myremote

> `

Follow the on-screen directions to train your remote and define keys. If your remote ends up working well, you should consider submitting your `lircd.conf` file back to the lirc developers. Once finished:

> `

>     $ su
>     # cp myremote /etc/lircd.conf

> `

now try to start lircd again:

> `

>     # /usr/local/sbin/lircd

> `

Now, we're going to add the commands necessary for lircd to run each time we boot. Mandriva 9.1 users, you can execute:

> `

>     $ su
>     # chkconfig --level 35 lircd on
>     # exit

> `

All other distributions:

> `

>     # cd /etc/rc.d
>     # cat >> rc.local
>     echo "Starting lircd"
>     /usr/local/sbin/lircd
>     ^D
>     # exit
>     $

> `

This takes care of the lircd portion, which "listens" for the IR signals. If everything went well, the install script for lircd put an appropriate configuration file for your remote into `/etc/lircd.conf` This file maps the buttons on the remote control to the IR pulses coming from the receiver.

The next step is to convert those signals into something that can be used to control MythTV. MythTV now includes native support for lirc and can interact directly with

> `

>     $ cd ~/mythtv-0.23/contrib/configfiles
>     $ cp lircrc.example ~/.lircrc

> `

or

> `

>     $ cp lircrc.example.pinnaclestudiopctv ~/.lircrc

> `

if you've got a Pinnacle Studio PCTV remote.

> `

>     $ irw

> `

Start pressing the keys on your remote; irw will print the name of the button as it is defined in your `/etc/lircd.conf`. If you don't see anything at this point, you need to troubleshoot further by going back to the lirc home page and investigating from there.

If it is working, then press CTRL-C to abort the program. Once you know that your remote is working, you can either recompile MythTV with native lirc support by enabling it in configure or you need to run the irxevent program, which takes the key presses and sends them to MythTV. If you use native lirc support, you don't need to run irxevent. If you are going to use irxevent, then you need to run it like this:

> `

>     $ irxevent &

> `

If irxevent isn't running, then MythTV will not respond to your remote control unless you're using native lirc support.

## 8.2 Additional information for lirc

Take a look at the lircrc.example files in the `contrib/configfiles/` directory. In my case, (Pinnacle Studio card) the channel up and down functions weren't working, due to the fact that the button names were different than the default `lircrc.example` file that came with MythTV.

The `lircrc.example` file has this:

> `

>     begin
>         prog = irxevent
>         button = ChannelUp
>         config = Key Up CurrentWindow
>     end

>     begin
>         prog = irxevent
>         button = ChannelDown
>         config = Key Down CurrentWindow
>     end

> `

but the `/etc/lircd.conf` that comes in the lircd package defines the buttons for the Pinnacle Studio PCTV as:

> `

>               channel+                 0x0000000000000017
>               channel-                 0x000000000000001C

> `

rather than "ChannelUp" and "ChannelDown". I added the following to my /home/[yourusername]/.lircrc file:

> `

>     begin
>         prog = irxevent
>         button = channel+
>         repeat = 3
>         config = Key Up CurrentWindow
>     end

>     begin
>         prog = irxevent
>         button = channel-
>         repeat = 3
>         config = Key Down CurrentWindow
>     end

> `

which took care of basic functionality. Because the PCTV Studio remote has additional buttons, look at the `contrib/configfiles/lircrc.example.pinnaclestudiopctv` for an example of how to define additional buttons, and how to debug potential button name conflicts between the `lircrc.example` file and how your remote defines the button names.

By examining the button names defined in `/etc/lircd.conf` and using the irw program to make sure that your remote is working, you can create the appropriate mappings in `.lircrc` to get excellent remote functionality with MythTV.

Note the repeat = parameter. This informs the `irxevent` program to pass through every third keypress. By default, `lirc` will only send one keypress to the application, even if you're holding down the key. The actual repeat = number will vary from system to system, so experiment and see which value works best for you.

## 8.3 Configuring lirc for use with an IR blaster

Lirc has support for various IR transmitters. A popular model is the Actisys IR-200L http://store.snapstreamstore.com/accessories.html. It was originally designed for IRDA communication, but can be used to transmit A/V remote control codes. By using the lirc SIR driver, this device can easily be integrated with MythTV. I have tested this device with an AT&T DCT2000 digital cable box but the instructions can be used to configure other IRDA devices and A/V remotes.

Follow the steps in the previous section. When you run setup.sh, select option 1, driver configuration. From here select option 6, IrDA hardware. Select your appropriate device and the corresponding serial port, then Save configuration & run configure from the main menu. Once configure is done type:

> `

>     $ make

> `

Please note: unlike the Pinnacle receiver above you will be compiling lircd in addition to a kernel module for the SIR transmitter. Depending on whether you have your serial port driver configured as a kernel module you might see the following message during make:

> `

>     lirc_sir.c:56:2: warning: #warning
>     "******************************************"

>     lirc_sir.c:57:2: warning: #warning "Your serial port driver is compiled into "

>     lirc_sir.c:58:2: warning: #warning "the kernel. You will have to release the "

>     lirc_sir.c:59:2: warning: #warning "port you want to use for LIRC with:"

>     lirc_sir.c:60:2: warning: #warning "setserial /dev/ttySx uart none"

>     lirc_sir.c:61:2: warning: #warning
>     "******************************************"

> `

If you do receive this statement make sure to run the setserial command before you load the lirc_sir module. Follow this with the install:

> `

>     $ su
>     # make install

> `

You will notice that lirc installs the kernel module in `/lib/modules/uname -a/misc`.

The configuration for starting lircd differs if you're going to be sending and receiving IR versus just receiving.

> `

>     # cd /etc/rc.d
>     # cat >> rc.local
>     echo "Starting lircd"
>     setserial /dev/ttySx uart none        # (if required)
>     modprobe lirc_sir
>     /usr/local/sbin/lircd
>     ^D
>     # exit
>     $

> `

At this point you have to populate the `/etc/lircd.conf` file with the proper codes for your A/V remote. You should be able to find your remote within the lirc remote tar file located at http://www.lirc.org/remotes.tar.bz2. In my case I extracted the file from remotes/motorola/DCT2000 (gi-motorola-dct2000)

To test the lirc_sir module you can run irw to verify the codes are being received. If everything is configured correctly you should see something similar to the following:

> `

>     $ irw
>     0000000000007ff0 00 1 gi-motorola-dct2000
>     000000000000bff8 00 2 gi-motorola-dct2000
>     000000000000f7f0 00 ENTER gi-motorola-dct2000

> `

Once you've verified lirc is working you can press CTRL-C to exit irw and configure the channel changing script.

The path to the channel changing script will need to be entered on the mythtv-setup screen for Input Connections.

This csh script will be called each time MythTV needs to change the channel. Below is a copy of the script followed by the corresponding perl script. Make sure both are in your path. Also make sure you leave the #!/bin/csh setting and not change it to Bourne or bash. This will create a frustrating symptom to diagnose where MythTV cannot open /dev/device. Unlike Bourne or bash, csh scripts automatically close parent file descriptors before they start.

> `

>     $ cd /usr/local/bin
>     # su
>     # cat > change_channel.csh
>     #!/bin/csh
>     echo "changing to $1"
>     /usr/local/bin/channel.pl $1 &
>     ^D
>     # chmod a+x change_channel.csh
>     # exit
>     $ exit

> `

See `contrib/channel.pl` for the actual file. Copy it to `/usr/local/bin/`

The last statement within the perl script is the lirc rc command. This is the command that transmits the code to your cable/DSS box. Make sure to have the IRDA device within a few feet of the box.

Next Previous Contents