[mythtv-users] LIRC Randomly Doesn't Work (Weird Solution)

[Douglas Wagner]

All:


     So I found something out tonight that I thought I'd post back to the
community at large since it was so odd, and fixed a problem.


For a few weeks now, my LIRC installation hasn't been working.  Given that I
have a wireless keyboard and mouse attached to my Myth box it's not been
THAT big a deal but tonight I got bored and decided that i'd go through and
try to figure out where my installation went wrong.  I've recently upgraded
to the 2.6.22 RedHat Kernel and figured that's where my problems started.


I did my usual checks and found that I did in fact have the correct kernel
drivers, that they are installed, the devices all have the right
permissions, etc.  Being confused about what could be wrong (all the config
files were still in place too) I decided to go back to the beginning and
start over again.  This is a "home brew" serial receiver (I didn't make it,
I bought from a guy who did make it) running on Com1.


So, reading through the LIRC docs, the first thing is to check that the
hardware works.


So I load the drivers (unload LIRCD) and run mode2.


Spam, and lots of it.  The mode2 app starts spitting out a CONSTANT stream
of pulse/wait messages.  Thinking this a bit odd I started pressing remote
buttons and I could see (before it spammed off the top of my screen) the
numbers changing as a pushed a button.  Now knowing that my remote worked
and that the drivers were ok I started trying to figure out why the receiver
was constantly spamming pulse/wait messages.  Being unsure if this was
normal or not (It's not btw.) I decided to see what would happen if I
completely shut off all light source to it.  I put my hand, tightly, over
the eye and the pulse/wait spam stopped.


Now knowing that the receiver will not spam if not receiving a signal
(which, I suppose should have been obvious but hey who ever said I was
smart?), I started trying to figure out what would cause the pulse/wait
spam.  Knowing there wasn't another infra-red device in the vacinity that
would be conflicting, and having an notion that using the remote in the
bright of day GENERALLY has worked in the past (it only stops working the
darker the room gets) I took a flashlight and shined it DIRECTLY into the
infra red iris.  (Sort of the "take a flashlight out into direct sunlight
and you can't see the beam concept).


The spam stopped...and even when I removed the light source, it stayed
stopped.  Loaded up LIRCD and IRW (which wouldn't report ANY keypresses
while the spam was going on) and bingo, remote shows fine.  Load up MythTV
and there you have it, full remote ability.


So I pose to the community that if you are having issues with LIRC loaded
and running, but your remote simply refusing to work at times, that
potentially holding a flashlight to the Eye can "correct" the issue.


Hey, I warned you all it was strange didn't I?


So, for those of you more technical on the hardware side, anyone have a
theory as to what gives?  Given that it didn't stop when I put my hand
around the iris but DID once I shined a bright light into it, I am pretty
sure i can rule out a source of infra red around the iris screwing it up...


Is it possible that an infra red signal is getting "trapped" and bouncing
around?  (Yea, ok, i'm grasping at straws here).  Why would darkness not
reset it (but it does stop it) but bright light took care of the issue?


Is there a more permanent solution anyone can think of besides having a
flashlight sitting by the TV all the time?


--Doug Wagner
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