[mythtv-users] IR blaster fails sometimes?

[Robert Denier]

On Fri, 2005-10-21 at 22:00 -0300, Mark J. Small wrote:
> 
> 
> Hi everybody , sorry if this is a double post...
> 
> I've got a recurring issue that is starting to really annoy me.  On many
> weeknights I record two consecutive programs on the same channel.  The first
> recording stops at at 00:35, and the second record starts at the same time.
> 
> Quite often, the second recording gets tuned to the wrong channel.  Last
> night, I got half an hour of Leno instead of Ghost in the Shell.  My ir
> blaster tuned my DCT2000 to channel 6 instead of channel 26.  The 2 got lost
> somewhere along the way.
> 
> When I look in my syslog, I can see the lirc events for each digit.
> 
> The 2 gets sent at 00:35:05
> The 6 gets sent at 00:35:08
> The OK gets sent at 00:35:09 (tell dct2000 to really change the channel --
> auto tune is off)
> The EXIT gets sent at 00:35:10 (kill dct2000 osd)
> 
> I think that the 3 second lag between the 2 and the 6 is causing my problem.
> By the time the 6 comes along, the 2 has been ignored.
> 
> On successful channel changes, the digits get sent every second.  (I pause
>  0.7 seconds between sends.)
> 
> I'm guessing that at the time of the failed channel change, the machine is
> heavily loaded.  But why would it happen for at 00:35 every night, thus
> killing the channel change for some of my favourite shows?
> 
> I checked, and there are no cron jobs running at 00:35 to slow things down.
> My cron.hourly is at 17 minutes past, my cron.daily is at 12:25 (noonish),
> and my cron.weekly and cron.monthly are between 4:00 and 6:00.
> 
> I looked through lots of logs, and I noticed that at 00:35:03, in
> mythtvbackend.log, there is a "reschedule requested for id 0"  This finishes
> at 00:35:08.  Is this what is slowing my machine down so much?
> 
> What can I do about it?
> 
> Faster CPU? More RAM? nice the channel change script?
> 
> My backend is a Duron 800 with 256MB RAM and 3 PVR 250s.
Try something like
nice -n -20 /usr/local/lirc-ledxmit/sbin/ledxmit-ledxmitd
in your init script for it.  If it works you may not want to leave it at
-20.  I'm not sure if that will cause problems.

If you just want to hunt for things going on around then and don't wanat
to stay up, you could put something like this in a script...

#!/bin/bash
LF=/tmp/logfile
while [[ 1 == 1 ]]
do
   date >> $LF
   top -b -n 1 >> $LF
   sleep 10
done

That file might grow really large so I wouldn't let it run forever...
This is a bit simplistic, but perhaps it will be helpful.

I have some issues with my IR blaster not being reliable as well
controlling a dish network 301 receiver.  I'm tempted to buy a my
blaster just to avoid having to debug the problem.  One person said the
gap setting in the  configuration file can matter a great deal, but I
have not found a reliable setting yet.  I also have not spent a great
deal of time on it yet.

Oh look I told it to record 300 and it switched to 30 and I missed the
first part of a show.  I'm not sure a MyBlaster is a perfect solution,
unless perhaps the extra receivers can be programmed in.  I suppose I
could use two of them...

Good luck with this..
-Robert