I spent 3 days trying to get my IR blaster to control the external tuner (a Bell ExpressVu satellite receiver). After much grief and hair-pulling, IT WORKED! I am now able to type:

change_channel.csh 577

...at the console, and the receiver dutifully changes to channel 577.

But for some reason, MythTV refuses to run that script! I ran mythtv-setup, went into the Inputs section, and added that script to the external channel change field. I even typed in the entire path (/usr/local/bin/change_channel.csh). I double, triple, and quadruple-checked my spelling. But no matter what I do, when I try to change channel in LiveTV, the receiver does not change channel. It doesn't even attempt to change channel. MythTV does not call on the change_channel.csh script at all!

Here's a checklist of things I went through to make sure I wasn't insane:

a) installed tcsh using apt-get (why isn't tcsh included in KnoppMyth by default? It seems to be necessary for most of the channel changing scripts I've come across)

b) made sure my channel lineup was imported properly from DataDirect

c) made sure all programming info was up to date and accurate

d) made sure I could change channels manually, both directly on the receiver and through a typed command at the console on the mythtv box

e) performed extensive searching on the mythtv-users and KnoppMyth lists/forums for some mention of a similar problem, to no avail (everyone else with a similar problem seems to have issues with their programming schedule, I do not)

Everything works as intended... MythTV pretends to change channel, the LiveTV buffer gets reset, the OSD info changes (accurately), but MythTV just does not change the receiver's channel.

What am I doing wrong? Why won't this script get triggered?

funny how I managed to solve this problem with a little more effort...

I checked /var/log/mythtv/mythtvbackend.log to see what was happening, and for some reason, mythtv was trying to run "change_channel" instead of "change_channel.csh". I'm not sure why the .csh was being omitted, it was clearly typed _with_ the .csh at the end. Anyways, I ended up renaming the script to just "change_channel".

Except that STILL didn't work! Further investigation in the backend log file showed that the script was now being executed (renaming it fixed that much at least), but the script was being run as the user "mythtv", and /dev/remote (the equivalent of /dev/lirc) was read-only for everyone but root. Since sending commands to the IR blaster requires write permission to that device, I changed the owner of /dev/remote to "mythtv".

And VOILA! Now everything works!

I suppose I could've tried typing in "sudo change_channel" as the channel change script, but I really don't care anymore. It works, that's all that matters.

Moral of the story...Check the logs!

_________________
cesman

When the source is open, the possibilities are endless!