[mythtv-users] New frontend... Atom?

Brian Wood beww at beww.org
Tue Nov 10 14:38:10 UTC 2009

On Tuesday 10 November 2009 07:27:39 Jarod Wilson wrote:
> On Nov 10, 2009, at 8:53 AM, Brian Wood wrote:
> > On Tuesday 10 November 2009 02:56:26 Steve Hill wrote:
> ...
> >> 3. Is there a serial port for me to hook an IR receiver to so I can
> >> continue using my Sky Navigator remote?  The POV says "internal
> >> COM", so
> >> that should be ok, the Asus board doesn't appear to have any RS232
> >> port
> >> and I can't see anything saying whether the Revo has one (either
> >> internally or externally).
> >
> > There are PCIExpress X1 serial port boards available, for when you
> > find a mobo
> > that's just right, with the exception of no serial port. The USB to
> > Serial
> > adapters can't be used with most IR blasters, I'm not sure if they
> > can be
> > used with IR receivers or not.
> Anything driven by lirc_serial, transmit or receive alike, will not
> work with a usb to serial adapter. The driver operates a too low a
> hardware level to function with a usb thingy in between it and the
> serial hardware. A pcie card could also be a problem if the serial
> ports are mapped to io addresses and or irq other than the standard
> com1/com2 ones, as lirc_serial has some nasty hard-coded limitations
> along those lines.

lirc toggles one or more of the handshaking lines (DSR/DTR, RTS/CTS) to drive 
an LED for the lirc blasters. IOW it doesn't actually use the serial port 
data lines (TXD/RXD) at all. 

This also means that very little current is available to drive an LED, which 
is why lirc blasters often need to be taped directly over the receiver's 

I'm not sure precisely how lirc works as a receiver, but I wouldn't bet on it 
working with a USB adapter, as you say.

> Any remote that works with a serial receiver ought to work just as
> well (if not better) with an mce usb transceiver. I highly recommend
> one of those over trying to shoehorn an old serial receiver or
> transmitter into a system w/o a serial port.

That's certainly the safest way to go, it's known to work, is easily available 
and is fairly cheap.

Brian Wood
beww at beww.org

More information about the mythtv-users mailing list