Controlling TV power on/off through HDMI

[colinjones]

Has anybody managed to control a TV's power (sleep/suspend) through an HDMI cable in the same way you can a VGA display using the xset commands? I would like to create a device to turn on and off my HDMI TV, but don't seem to be able to find even a command line that will do it. It doesn't seem that xset makes any translation for HDMI is that is what is connected, however I have seen a friend's VMC turn his (identical) TV on and off using an HDMI connection so it must be possible!

[merkur2k]

if your tv supports it, the following should work as a test:

Code:

export DISPLAY=0:0
xset dpms force off

also can use 'suspend', 'standby', and 'on' in place of 'off' above.

[colinjones]

merkur2k

You have this working over HDMI not VGA?

Yes, I have tried all combinations of the above in the past, and the TV does not react at all. As I say, a friend has the same TV and it works without any issue, so I assumed it was using some other mechanism rather than dpms which is more a VGA thing, although I hoped that HDMI in some way simulated the DPMS lines.... if you have this working over HDMI then maybe it does and something else is wrong ....

[merkur2k]

no i dont have it working at all, my tv doesnt support it apparently.
for my tv at least, all any of the commands do is cause it to complain about no signal.

[colinjones]

actually come to think of it, yes, I think that's what mine does too! I suspect though, that this is just because the video output is turned off as well as signalling the dpms to switch the display off. So the TV ignores the off command and the GPU stops outputing a signal... thus we see what we see....


hmmm still doesn't explain how my friend's Vista MCE does it... there must be a way...

[fastie81]

how do you guys know witch tv and model support this??

[merkur2k]

i believe i read in the manual for my tv that the vga port will support it, but the hdmi port will not. many tvs are this way i think.

[fastie81]

damm I need to see if my Sony does that save me digging around wit USB-Uirt and shitt..

[tschak909]

HDMI CEC right now is still in its infancy, and is protected heavily by intellectual property laws. This means that significant reverse engineering will need to be done to send control codes over the HDMI port, assuming of course, that the video cards in question will provide a link to do this.

-Thom

[colinjones]

HDMI CEC right now is still in its infancy, and is protected heavily by intellectual property laws. This means that significant reverse engineering will need to be done to send control codes over the HDMI port, assuming of course, that the video cards in question will provide a link to do this.

-Thom

Agreed, Thom, nevertheless I have no reason to assume that 1) Vista MCE would be any better at using Samsung's AnyNet (CEC) than LMCE, nor that even if it was able to, that my friend would have the faintest clue how to set that up! Which is why I was considering the possibility that it is using some legacy approach similiar/same as DPMS.... I guess nobody here is certain whether HDMI connections do support anything other than CEC? I have to wonder, though, how "ordinary" PC users handle this if they happen to use HDMI to connect their PC to a monitor (yes, I realise this is likely to be rare unless we are talking about a media centre.... but...)

[merkur2k]

I believe the monitor can support DPMS over hdmi if the manufacturer wants to. it should be no different than dvi, which does work. there was a device template for this added recently.

[lmwashere]

merkur2k,

I cannot find that DVI monitor template, is there any way that you could point me in the right direction?


Thanks,
Josh

[totallymaxed]

I believe the monitor can support DPMS over hdmi if the manufacturer wants to. it should be no different than dvi, which does work. there was a device template for this added recently.

This is certainly correct. However support is patchy at best and is certainly not the norm.

The problem with CEC is that it is a bit like Zigbee in that yes its a 'standard' but every vendor implements it differently...it is nowhere near interoperable at all. We talk to a lot of professional CI's and none of them even see CEC as being viable as a generalised control standard.

All the best

Andrew

[lmwashere]

I would be happy if there was something that would terminate the signal going to the monitor. That will send the monitor into standby, which is more than fine. I was looking for the template because I am using an lcd monitor as a tv for this MD. I plugged it in with a dvi cable and I cannot seem to get it to switch off or over to standby. Kubuntu, ubuntu etc have no problem with it, I guess I am just not sure how to handle it in LMCE. I posted details about it here: http://forum.linuxmce.org/index.php?topic=9973.0

Thanks for your help and quick reply.
Josh