i believe that this works for vga attached monitors, vesa says that when the clocks
disappear on the sync the monitor should shutdown.

the raspberry pi uses hdmi and also it doesn't use a vesa bios, it has a gpu bios
which does a similar job but is not standardised, and, though it is documented,
it can be tough to use (for me at least).

i am happy to be contradicted on any of this of couse.

-Steve




On 16 May 2014, at 04:53, Shane Morris <edgecomberts@gmail.com> wrote:

This might be wildly off the mark, but is there something VESA related to do this, VGA monitors, et al?

I prepare to stand flamed. ^.^


On Fri, May 16, 2014 at 8:26 AM, Bakul Shah <bakul@bitblocks.com> wrote:
On Thu, 15 May 2014 22:04:34 BST "Steve Simon" <steve@quintile.net> wrote:
> Its just wonderful to have a raspberry pi as a plan9 terminal,
> but the energy saving of the pi is outweighed by the monitor I use.
>
> The Pi's display code blanks the screen after a while but this does
> not shutdown the monitor.
>
> I dug a little and it seems I need to send CEC (Consumer Electronics Control)
> messages over HDMI - Via a Pi GPU entrypoint.
>
>
> Porting libcec looks a little painful especially as I only need to be able
> to send two messages (turn on and turn off).
>
> Anyone know anything about this stuff? is CEC what I need or is there some
> other (simpler) way?

May be use a gpio pin to control a switch?!