[mythtv-users] USB dual channel IR blaster?

Brian Wood beww at beww.org
Mon Feb 22 17:45:06 UTC 2010


On Monday 22 February 2010 10:38:39 am Mark Knecht wrote:
> On Mon, Feb 22, 2010 at 9:35 AM, Brian Wood <beww at beww.org> wrote:
> > 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.
> >

> 
> Like this sort of thing?
> 
> http://www.serialgear.com/PCI-E-Portpress-Cards-PCIe-2RS2LP.html

Not precisely, but similar. Looks like that one actually follows the RS-232C 
standard by having 2 ports on a single DB-25 connector (like the old Sun 
machines), and has a splitter to split out the ports.

That price is better than I got, but I bought mine a couple of years ago. 

The blurb doesn't mention Linux support, but neither did mine, but it worked 
out of the box with Debian and FC.





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