Setting up an IR Blaster for Mythtv under Kubuntu

Comcast is moving to an all digital format, requiring mythtv installations such as mine that were operating off of their analog feed to install either one of their digital boxes or a DTA (Digital-to-analog) box in order to continue receiving their signal. The problem is that one can no-longer control the television station being received through the tuner seated in your computer.

The solution is to install an infrared blaster (a device that emulates the remote control) on the PC and use it to change the channels on the DTA comcast provides.

Being Linux that is neither as easy as it sounds nor is information on how to do it as easy to find as you might hope. I am writing this as an aide memoire so that if I upgrade or whatever I can find all of the pieces and infos needed. Hopefully it will also help someone else.

First the hardware.

I purchased an IR blaster for 12.95 from IRBLASTER.info, which is recommended on various mythtv web sites. It works of any free serial port on your computer -- which sounds easy, except thereare no serial ports on my system -- having been more or less made obsolescent by cable modems and USB ports (the world keeps moving on)!

A little digging and I found that on the motherboard (an XFX GEFORCE 8200) there was an outlet for connecting a serial port. As I had a serial port attached to a ribbon connector lieing around from an old computer I was able to get around that -- but given there was no documentation of the MoBo I had no idea whether I had installed it correctly.


Now the software.
After a lot of digging including reading the really useless (outdated and needlessly complicated) discussion of installations that the IR Blaster site links to I found an excellent how to here that covers all the steps necessary to make this device work while I found a LIRCD.conf file for the PACE DTA50 supplied by comcast here here .

The instructions worked almost flawlessly except that having a slightly newer version of Ubuntu (Jaunty Jackelope) than documented (Hardy Heron) some things did not work out exactly as described. However, work arounds came relatively easily.


Getting LIRC to run properly

The biggest trick was to get LIRC running properly. There are all sorts of sites on the web describing what are really complicated solutions here. The one I found that worked relatively easily (with some modification) was the official MythTv Ubuntu install.

It gives great step by step instructions that work (with some blips along way).


Blip 1
The site tells you to execute the following line

sudo dpkg-reconfigure lirc-modules-source

and advises you that a

"A Configuration should appear
Choose the OK button and press enter (tab key to move across)
Make sure only the serial module is selected, use the space bar to select,
and then press enter on OK
You will be given an option to build the modules. Be sure not to build the modules here
You may be given an option to replace with a new version. Be sure to
choose to Install the package maintainer's version"

However this configuration does not appear. 
This is not a problem -- there is a note to this effect in the
current version of the site.


Second Blip

A bit later the how to suggests that you execute the following commands.

sudo m-a update,prepare
sudo rm /usr/src/lirc*deb
sudo m-a clean lirc
sudo m-a a-i -f lirc
sudo depmod -a

On my system this all worked fine except that the last command
popped up a text-based dialog indicating that there were errors and asking
if I wanted to see the log.  I looked at the log and it was broadly uninformative.
As it turns out whatever the problems that were encountered they did not affect my
installation and all worked fine.



Third Blip(let)

When I got to the section entitled 

Remote Configuration

I just used the configuration file that I had found here to create a lirc.conf file for the PACEDTA supplied by Comcast.



Fourth Blip -- Use the PACEDTA file directly as your lircd.conf
One of the most important features of this site is it includes a definition of the LIRC file that will send the right commands to your dta so that the blaster can actually change channels etc. V. useful.

One hiccup I ran into was that the using the include command in lircd.conf as described on the site did not seem to work. I got around that by overwriting the lircd.conf file with the specific one provided on the how to site.

With those small modifications, I had my blaster up and running in a bit under two hours. Not bad.


UPDATE

As indicated above I moved over to Karmic Koala (not a smooth process). Anyway there I has to recreate a ch_chan.sh script to change channels. I placed this in /usr/local/bin/ch_chan.sh