Strange problem with mythtv

[kskrauter]

I need to use mythtv with an external tuner. I did use BeyondTV under windows
with USB-UIRT and it worked perfectly. However, with lirc and mythtv I have a
weird problem. I compiled lirc-7.1pre3 with the USB-UIRT patch and it reads
and writes perfectly well using irw and irsend. However as soon as I start mythtv,
irsend sends double codes (I posted this earlier before I realized what was happening).
It does this both from within MythTV with the change-chan scripts or from a separate window and commandline irsend.

Questions:
1) Is anyone out there using USB-UIRT to both receive and change channels with mythtv?
2) What can MythTV be doing to cause this? There are no new drivers loaded or
new /dev files created after starting Myth. I have tried virtually every permutation
of starting lirc/myth/looking at the code for lirc etc. Problem seems to be with
Myth. When I stop Myth, it goes back to single digit transmission.
3) If I start Myth with no .lircrc file, I get the usual error that the file is missing on startup
and then it transmits codes just fine. However, it can no longer receive codes.

Any ideas would be greatly appreciated! I am feeling pretty stupid.....

Ken

[plop]

I have the same problem - here is a cut & paste of a post that I made at a different forum :

####
FC3, Mythtv 0.18, lirc-0.7.0pre7 with neveld's USB UIRT patch.

An irsend command will work perfectly as long as it is the only process
connecting to lircd. Once another process connects to lircd (like
mythfrontend for example..) from that moment on all irsend commands seem
to be repeated - each digit/command now being sent twice. The only way to
get the irsend working again is to restart lircd, but this breaks all
pre-existing client connections - like recieve for the mythfrontend ...
####

Please let me know if you've made any progress with this ...

Scott

[kskrauter]

I beat myself up for about a week trying various tweaks and googling. Finally, gave up when I discovered that Comcast (my cable company) was supporting the Motorola 6200 box (previously only the 5100). I unplugged the old box, did a free swap at my local cable office, plugged in the firewire line, compiled the nifty bit of code in /usr/share/doc/mythtv-0.18.1/6200ch.c and VOILA! I use the USB-UIRT for input only and let the firewire change the channels for mythtv. It has the virtue also, of NEVER making a mistake because of room light or whatever that the blaster solution was plagued by. Also, no extra hardware propped up in front of the box.

Sorry I couldn't really find a solution - but I will keep my eye out. I see that LIRCD still does not support this device even though it is really a great piece of hardware. Funny how the windoze guys at Sage and BeyondTV have this baby working - Sage is written in a sort of perl I think!

[/quote]

[plop]

Glad that you got your system working - I'm still banging my head against mine. I'll call my cable co (adelphia) and see if there are any firewire boxes available now. I have tried to convince them to enable the serial port on the box that I have to no avail.

So close, and yet so far .....

[kskrauter]

Seems like you could bite the bullet and just buy a serial blaster - one of the ones supported by lirc. I think you can find one for under $25. I don't sense a groundswell of interest at USB-UIRT to get linux going on this device.

[plop]

Yeah - I have considered that option, but then I'll be unable to use the serial port for the X10 controller ...

Seems such a shame too, as the USB UIRT is really the most elegant almost solution.

[jrhees]

Sorry guys that I'm not much help here getting this working. I am unfortunately not familiar with the Lirc implementation.

I wonder if there is some setting in Lirc which affects how long a code is sent for (i.e., which alters the 'repeatCount' setting sent to the USB-UIRT when transmitting). This could cause repeated codes.

The way to know if something like this is happening is to watch the LED on the USB-UIRT. If it only flashes once for each digit yet your set-top-box sees double digits, then this would be an indication that the repeatCount setting is too high (like holding your finger on your remote too long). Another way to see this would be to watch how *long* the LED lights up for -- which is an indication of how long the code is being transmitted. Perhaps this value is different between when mythTV uses Lirc and when you use the command line.

-Jon

[Guest]

Hey Jon - I think that we have both experienced the same issue, in that it is not that a code is being sent for too long, but that when there are two clients connected to lircd each send is actually repeated. In my experience, the state of the lircd daemon appears to be toggled by a connection from a mythfrontend client in that once an instance of lircd has seen a connection from mythfrontend, any irsend after that point will be repeated, even if the mythfrontend process disconnects, until the lircd daemon is restarted.

As I write this, I am trying to remember if I see this behaviour with multiple lirc clients connections - like if I run irw and use irsend while irw is connected - I'll try that tonight and post my findings...

[plop]

Okay - that took a little longer than anticipated ...

It turns out that a connection from any other process to lircd will trigger this behaviour. I tested this by restarting lircd, and doing a couple of test irsend's - which worked just fine. I then fired up an instance of irw in another shell - as soon as I had done this irsend began repeating. If I killed the irw process, the irsend's began working properly again.

I also observed this behaviour with the lircmd mouse daemon causing repeat sends when connected to lircd.

[jrhees]

Is this a bug in Lirc?

-Jon

[Guest]

Kinda hard (for me an any rate..) to say if it is an lirc thing, or something more specific to the lirc-usbuirt patch. As far as I can tell, there is not much support for bi-directional devices in lirc - with the possible exception of the fairly expensive IRTrans device. Most people seem to use the devices in one direction only - so there are not hoardes of people experiencing this problem with the UIRT.

With the current groundswell of interest in Media PC's, HTPC's and BYO PVR's I'd have thought that there would be alot of interest in a device that solves the IR IO problem - it really is the last piece of the puzzle, and although a critical part of a homebrew PVR is often overlooked - there are suprisingly few options out there...

[jrhees]

FWIW. A Linux API is in the works and once it is ready I'll look into changing the Lirc USB-UIRT layer to use the new API (or maybe look into having MythTV use the API directly and bypass Lirc).

-Jon

[btek]

I am fighting the same battle. However I am not so lucky to ever get a single character out to the receiver. No matter what I do, if Myth is running or not, I get a double "key press" when I run irsend. Like it was said below this is the last major thing in the system before Myth is really complete. If anyone has any ideas it would be greatly appreciated. I am trying to find a work around ( or even a hack to the code ) to get past this. It doen't need to be pretty it just needs to work at this point.

[Guest]

I was even getting triple presses for a while until i deleted some stuff...


The solution for now is to do only one thing at a time.

A script that removes your lircrc file, restarts lircd, does the cnannel blasting, then returns the lircrc file and restarts lircd might work...

For the very short term i run lircd without any lircrc files to keep the channel changing in mythtv working so i can record movies.

I read about sharing a single serial connection by using two instances of lircd one refered to as irblaster. We might need to set up a similar hack.

[john]

This must be more of an issue with how LIRC deals with a single serial (or USB serial) device

But people got it working. Is anyone here smart enough and passionate enough about the USB-UIRT to make a similar HOW-TO tailored for the USB-UIRT?

http://www.iwamble.net/6901.html