[mythtv-users] Power Relay for Frontends

[tortise]

On 27/10/2012 11:07 p.m., stinga wrote:
> On 27/10/12 01:28, tortise wrote:
>> One simple variable seems to be the type of monitor - either it can be
>> powered off with no risk of ill effect - or it can't, which then makes
>> it all much more complicated.
> I was thinking about getting the monitor to power off the PC not the
> other way around, would just need to see if wake on USB would work!
>
> Then I thought... hmm, hdmi has a 5v supply

I can get the 5 V from the TV's USB, or probably as you say via HDMI, 
what I want to do is be able to read that 5V somehow by the frontend so 
I can run a script off it,

If Sense = 5v {
Do...
}
else 'Sense is < 3V means monitor is off
{
Do alternative
}

How can I most simply connect the monitor to sense.
Could do it with EDID but not all monitors have EDID....

I am wondering if I can do it using a serial port?