[mythtv-users] How about a "Now Recording" red light?

[Jason White]

> Has anyone found a way to hook up an external LED that will go on when
> MythTV is recording?  I'm thinking of doing something like sending a
> steady
> signal to the serial port, but not sure if it would be enough to light
up
> an LED..  I spose you could use the Hard Drive light switch, but I'm
> picky.. ;)

I've not personally done it from myth or Linux for that matter, but I
suspect that with a little work that the parallel port would work well.
It outputs TLL voltage levels with sufficient current to drive an LED
(with a small series resistor so that you aren't just shorting 5V to
ground when it's on).  Under Windows this isn't difficult.  

Do a google search for "linux parallel port dio".  The comedi driver is
one link that'll come up.  It is for third party data acquisition and
DIO devices but it also has some parallel port support.  There may be
others as well.  This type of configuration is used a lot in academia in
EE labs for people to create simple ways to test their digital designs
without having to put additional hardware in their PCs.

Jason