[mythtv-users] USB dual channel IR blaster?

Brian Wood beww at beww.org
Mon Feb 22 17:35:13 UTC 2010


On Monday 22 February 2010 09:58:18 am Mark Knecht wrote:
> On Mon, Feb 22, 2010 at 8:30 AM, Brian Wood <beww at beww.org> wrote:
> > On Monday 22 February 2010 09:27:11 am Tony Brummett wrote:
> >> On Mon, Feb 22, 2010 at 2:06 AM, Johnny Stenback <myth-users at mythtv.org>
> >
> > wrote:
> >> > On 02/21/2010 08:10 PM, Tony Brummett wrote:
> >> >> I'm starting to gather parts to put together a new backend machine.
> >> >> [...]  I'd keep using that kind of set up, except that it seems
> >> >> that modern-ish motherboards only have one serial port anymore.
> >> >
> >> > True, lots of modern mb's only have one serial port, but they all have
> >> > plenty of USB, and USB to serial adapters are a dime a dozen (maybe
> >> > not quite, but $7 or so on eBay last I looked) so I'd just get one of
> >> > those and keep using the blasters you already have.
> >>
> >> Since LIRC uses the port in a non-standard way, USB serial adapters
> >> won't work.
> >
> > Correct, lirc toggles the handshaking lines to drive an LED. The
> > MyBlaster uses the serial port in the standard way (using txd and rxd) so
> > it will work with USB adapters.
> >
> > Al the OP alluded to, there are PCI Express X1 cards available with a
> > couple of serial ports on them, which will work with lirc type blasters.
> > Most modern mobos have at least one X1 slot.
> 
> Each time I run up against this problem (tuning an external device
> with IR) I back away. Recent motherboards I've looked at no longer
> have __any__ serial ports. Most of the ones I'm looking at don't even
> have PCI slots in favor of things like 1x/8x/18x PCI-Express and
> eSATA. I had to purchase a more expensive MB a few weeks ago to even
> get 3 PCI slots. PCI is going away.
> 
> Is there any really reliable and inexpensive (say <$30 per IR Blaster)
> technology that allows multiple blasters on a single modern PC? (No
> serial, no PCI)

I think I paid about $60 for a 1x card with 2 serial ports, so that would be 
about your price point, if you don't count shipping. The card says 
"StarTech.com" on it, but I've seen the same card with other names. It came 
with both a low-profile and a standard bracket. If using both ports with the 
lo-pro bracket you have to use the header on the card for the second port, the 
lo-pro bracket has only a single DB-9 connector, the standard one has 2.

There are also USB solutions like the MCE units, but i don't know much about 
them.


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