[mythtv-users] Re: MythTV and Sky

Allan Stirling Dibblahmythml0015 at pendor.org
Tue Aug 2 20:48:12 UTC 2005


mythtv guy wrote:
> --- Allan Stirling <Dibblahmythml0015 at pendor.org>
> wrote:
> 
> 
>>mythtv guy wrote:
>>
>>>Allan,
>>>
>>>Your solution interests me as it is what I would
>>
>>have
>>
>>>liked to do in the first place.  You have inspired
>>
>>me
>>
>>>to try it myself - I am driving the serial port
>>
>>DTR
>>
>>>through a voltage divider into a CMOS inverter to
>>
>>give
>>
>>>me a 5v inverted signal which i can feed into the
>>
>>box
>>
>>>in place of the IR sensor signal.  In fact I am
>>>AND'ing the two together so either the IR sensor
>>
>>or
>>
>>>the DTR signal can be used.
>>>
>>>Trouble is it would appear as though the remote
>>
>>codes
>>
>>>in my lircd.conf file are no good for this
>>
>>approach.
>>
>>>The sky box certainly doesnt recognise commands
>>
>>sent
>>
>>>from the PC and when I monitor it on an
>>
>>oscillosope
>>
>>>the waveform seems to be every different to that
>>
>>seen
>>
>>>when I press the equivalent buttons on the remote.
>>
>> Do
>>
>>>you have a copy of the lircd.conf file you used
>>
>>that
>>
>>>you could send me?
>>>
>>>At first I missed off the lirc_serial options you
>>>mentioned and I hoped that would be the problem
>>
>>but
>>
>>>even after adding them it still behaves the same
>>
>>way.
>>
>>>Do you have any other ideas why this wouldn't be
>>>working.  Having got this close I would love to be
>>>able to see it through now.
>>>
>>>Thanks for any help you can give.
>>>
>>
>>Is this Sky or Sky Plus?
>>
>>Isn't AND the wrong operation? Don't you want XOR?
>>
>>Cheers,
>>
>>Allan.
>>_______________________________________________
>>mythtv-users mailing list
>>mythtv-users at mythtv.org
>>
> 
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> 
> 
> Allan,
> 
> It is normal sky (not sky plus)
> 
> The reason I use an AND is that both the signal from
> the existing IR sensor and from my PC (via the
> inverter) are normally 1 and if either goes to 0 I
> want that to be seen by the digibox.  If I was to use
> an XOR then the output would be 0 in the quiescent
> state as both inputs would be 1.
> 
Doh. Sorry - Been trying to take a backup of 1.4Tb onto DVDs. I'm a 
little tired :)

> i am not sure of my observations with my oscilloscope
> as it is very old and does not have digital storage
> but i am not sure what else to try other than to give
> up with this and try with a normal IR emitter attached
> to the PC.
You shouldn't need storage, as you can set the sequence to repeat 
(SEND_START instead of SEND_ONCE), then you just have to figure out how 
to trigger it :)

Compare the amplitudes of the signals from the internal sensor and your 
voltage divider.

Double check you are actually loading the module with the correct 
options - On Gentoo, I need to tell it when I've modified one of the 
module parameter files.

If all fails, try removing the hardware trickery and doing the same 
cheat that I did.

> 
> Once I have set softcarrier=0 I assume the standard
> sky remote codes in lircd.conf will work as if I was
> using a IR transmitter?
> 
> Regards
Should do. I'd also try recording your own remote and seeing what that 
does for you.

Cheers,

Allan.


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