[mythtv-users] IR Blaster and Channel change script for Myth TV

Brian Wood beww at beww.org
Mon Sep 18 18:31:34 UTC 2006

On Sep 18, 2006, at 12:00 PM, Nick wrote:

> On 18/09/06, Ramanraj Vamsi <ramanrajvamsi at gmail.com> wrote:
>> Hi Nick,
>>  But I am using a Hauppauge IR blaster Remote that came with the  
>> card.Does
>> this mean that I have to use a DVB with a known code set(currently  
>> I am
>> using Zenega CD-1004S for which I have n't come across the code  
>> set number
>> in any link on that blog as well as the link specified in previous  
>> thread)?
>>  How can I make my IR Blaster control my STB?
>>  Any suggestions will be highly appreciated!
> If you have an unused serial port on your computer, the easiest way to
> control your STB may well be to build/buy a serial port IR blaster
> (this is what I did).
> Your PVR-150 blaster is limited in the IR codes it can use, and it
> would appear from your results that the blaster cannot emit codes that
> will control your particular STB (did you try the 0863 code suggested
> by Rick earlier?). Therefore, you need to find another way of
> controlling it - and from experience the best way I have found is to
> use a homebrew serial port IR transmitter (schematics on lirc.org).
> Some STBs let you control them using a direct serial cable connection
> but you must know for sure whether this is possible with your STB.
> However, in order to be able to use \any\ transmitter with your STB,
> you need to know which IR codes it uses. If the codes are not
> available from the lirc.org site, I would use a serial port IR
> receiver to record the STB remote's codes directly. However, as you
> are using the PVR-150 IR receiver - you may well have problems
> recording the remote, as Hauppauge IR receivers are limited to
> receiving RC-5 based IR signals. Have you tried using irrecord to
> record the STB's remote control?
> It probably appears that there is no end in sight yet - I think that
> of all the things that could cause problems for you, you have
> experienced nearly all of them so far. From my experience using IR
> with external STBs and remote controls, the things that I have proven
> to work are serial IR receivers and transmitters.

The serial IR blasters fall into two categories: The "dumb" ones that  
are pretty much just LED drivers and depend on LIRC to generate all  
of the timing and codes etc., and the "smart" ones like the MyBlaster  
that just need to be fed some basic info, like what code set and what  
instruction, via the serial port. The latter can usually "learn" from  
a remote transmitter as well as a pre-set list.

Although the "smart" blasters cost a few dollars more, they are much  
easier (IMHO) to get going and require a lot less smarts from the  
control program, of course with that comes a lack of flexibility to  
some extent.

I played around with homebrew blasters and probably spent more on  
soldering supplies than anything else. Thanks to William Munson's  
very flexible perl script I was controlling my satellite receiver 10  
minutes after taking a MyBlaster out of the box.

So you can spend around $15 and several hours getting it to work, or  
spend $45 and 15 minutes, just depends on what your resource  
availability is I guess.

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