[mythtv-users] Controlling STB with Lirc

[HP-mini]

On Tue, 2013-05-28 at 13:01 -0400, George Nassas wrote:
> On 2013-05-28, at 11:22 AM, aaron wrote:
> > On 2013-05-27 5:34 PM, "Rick" <rbonafied at gmail.com> wrote:
> > > I use my PVR-150 IR Blaster to control a comcast STB.  Something I
> > > discovered was the IR Blaster had to be at the exact right spot
> > for the
> > > STB to read the signal.  I'm told the IR Blaster doesn't send a
> > "strong"
> > > signal
> > 
> > Thanks for that. I had been placing my transmitter a fair bit back
> > from the box, so I thought maybe I need it closer
> > 
> I recall seeing an article about how hauppauge had made a mistake in
> the ir transmitter which greatly reduced its range. The author
> described a simple mod, a resister and led IIRC, but I can’t seem to
> find a link. The best I can come up with is this
> mention: http://forums.gbpvr.com/showthread.php?20168-Hauppauge-IR-Emitter-with-MCE-Remote-Kit&p=144663#post144663
> 
> 
> Wish I could be more helpful but while you’re struggling you might
> keep in mind that the stock hardware is working against you and see if
> your googling skills are better than mine.
> 
> 
> - George
Something to bear in mind..
All IR receivers have AGC in their input stage so they are able to cope
with wide dynamic range of input signal levels.

The AGC stage requires a certain time/number of pulses (bursts of
carrier) to stabilise. This can vary from 2 to >20 pulses.
With no input signal the IR receiver will be at maximum sensitivity.
This AGC is also affected by ambient lighting from electronic ballasted
CCCF & LCD backlighting.

Maybe the IR blaster h/w or software is not providing a suitable
preamble for the IR receiver.