From mboxrd@z Thu Jan 1 00:00:00 1970 References: <20140515222634.8E091B82A@mail.bitblocks.com> From: Steve Simon Content-Type: multipart/alternative; boundary=Apple-Mail-A8E75497-C244-4CF9-B4CA-BAD40685C86C In-Reply-To: Message-Id: <761B3FC6-018E-4663-AFFA-452BCC3B410A@quintile.net> Date: Fri, 16 May 2014 09:45:53 +0100 To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) Subject: Re: [9fans] RaspberryPi, monitor energy saving Topicbox-Message-UUID: e6af6afa-ead8-11e9-9d60-3106f5b1d025 --Apple-Mail-A8E75497-C244-4CF9-B4CA-BAD40685C86C Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable 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 document= ed, 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 wrote: >=20 > This might be wildly off the mark, but is there something VESA related to d= o this, VGA monitors, et al? >=20 > I prepare to stand flamed. ^.^ >=20 >=20 >> On Fri, May 16, 2014 at 8:26 AM, Bakul Shah wrote: >> On Thu, 15 May 2014 22:04:34 BST "Steve Simon" 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 Co= ntrol) >> > messages over HDMI - Via a Pi GPU entrypoint. >> > >> > >> > Porting libcec looks a little painful especially as I only need to be a= ble >> > to send two messages (turn on and turn off). >> > >> > Anyone know anything about this stuff? is CEC what I need or is there s= ome >> > other (simpler) way? >>=20 >> May be use a gpio pin to control a switch?! >=20 --Apple-Mail-A8E75497-C244-4CF9-B4CA-BAD40685C86C Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
i believe that this works for vga atta= ched monitors, vesa says that when the clocks
disappear on the syn= c the monitor should shutdown.

the raspberry pi use= s hdmi and also it doesn't use a vesa bios, it has a gpu bios
whic= h does a similar job but is not standardised, and, though it is documented,<= /div>
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 s= omething VESA related to do this, VGA monitors, et al?

I p= repare 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 "St= eve Simon" <steve@quintile.net&= gt; 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 Co= ntrol)
> messages over HDMI - Via a Pi GPU entrypoint.
>
>
> Porting libcec looks a little painful especially as I only need to be a= ble
> to send two messages (turn on and turn off).
>
> Anyone know anything about this stuff? is CEC what I need or is there s= ome
> other (simpler) way?

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


= --Apple-Mail-A8E75497-C244-4CF9-B4CA-BAD40685C86C--