Turn off TV automatically?

Message

grant123 · Post by **grant123** » Mon Dec 08, 2014 1:44 pm

I'd like the TV which is connected to my computer to turn completely off after a specified period of inactivity. It sounds like DPMS is the way to do this, but it only seems to blank the screen, the TV itself does not turn off even though it is Energy Star certified. I've tried both of these:

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# xset dpms force off

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# vbetool dpms off

krinn · Post by **krinn** » Mon Dec 08, 2014 2:35 pm

you could have a device that is not vesa but still energystar as earlier device do, but for a tv connected to a computer, i hardly think of any tv that could be plug to a computer that doesn't know vesa exists...

still, and this even today, poor manufacturers can claims to be using a standard but are not respecting it in real.
or maybe you expect something that it shouldn't do, dpms off will not completely turn off the device, but put it in the best energy saving state (so not off, as it still need energy to get out of sleep or keep some led activity)

Fitzcarraldo · Post by **Fitzcarraldo** » Mon Dec 08, 2014 3:28 pm

As far as I know the xset dpms command only works if you're using a VGA connection:

Wikipedia article on DPMS wrote:The standard defines how to signal the H-sync and V-sync pins in a standard SVGA monitor to trigger the monitor's power saving capabilities.

Is your PC connected to your TV via VGA or HDMI?

If you are using HDMI, does your video card support the HDMI CEC (Consumer Electronics Control) protocol? If not, the library libCEC is available for a Pulse-Eight USB-to-CEC adapter, which might do the job in your case.

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$ eix libcec
* dev-libs/libcec
     Available versions:  2.1.3 (~)2.1.4 (~)2.2.0 {cubox debug exynos raspberry-pi static-libs xrandr}
     Homepage:            http://libcec.pulse-eight.com
     Description:         Library for communicating with the Pulse-Eight USB HDMI-CEC Adaptor

More information is available in the KODI Wiki article on CEC.

grant123 · Post by **grant123** » Mon Dec 08, 2014 4:38 pm

I'm connecting via HDMI and it looks like my LG TV does support HDMI-CEC and calls it "Simplink". My device is a Gigabyte Brix 2807 with Intel graphics and I'm not sure about its HDMI-CEC support. I get:

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# cec-client -l
Found devices: NONE

So I probably need that USB device which I'd rather not use. Thank you and please let me know if you have any other ideas.

szatox · Post by **szatox** » Mon Dec 08, 2014 10:13 pm

LPT-controlled power switch cutting off the power flow to the TV?

grant123 · Post by **grant123** » Mon Dec 08, 2014 11:25 pm

LPT like a parallel port? How would that work?

szatox · Post by **szatox** » Tue Dec 09, 2014 6:39 pm

Well, it was intended as a joke, but you can indeed control LPT easily with software and there is easy and safe way to switch another circuit with this signal. http://en.wikipedia.org/wiki/Contactor
Those things allow you controlling high voltage and high current wires with little power while air-gapping (litteraly) whatever you use as controler so you can be sure you will not fry this squishy, 5V source with 330V spike (or whatever it is during cycle's maximum).
You can also try semiconductor-based solution if you're not afraid of soldering, but you will want to think a bit on making sure there is resonable separation. You know, you can get electrocuted. Even worse, you can lose your data.

russK · Post by **russK** » Wed Dec 10, 2014 5:52 am

LIRC with an IR transmitter or blaster could help avoid interfacing with high voltage circuits.

http://www.lirc.org/index.html

Ant P. · Post by **Ant P.** » Wed Dec 10, 2014 3:32 pm

Have you tried looking in the TV's menu for a "power off with no signal" option?

grant123 · Post by **grant123** » Thu Dec 11, 2014 1:59 pm

I don't think I'll go the LPT route.

The TV has an RF remote instead of IR unfortunately.

The TV does power off with no signal, but it takes too long to do so and I don't see an option for adjusting that in the TV menu.

It sounds like I'm out of luck but thank you for your help.

turtles · Post by **turtles** » Thu Dec 11, 2014 4:55 pm

Fitzcarraldo wrote:As far as I know the xset dpms command only works if you're using a VGA connection:

Wikipedia article on DPMS wrote:The standard defines how to signal the H-sync and V-sync pins in a standard SVGA monitor to trigger the monitor's power saving capabilities.
Is your PC connected to your TV via VGA or HDMI?

If you are using HDMI, does your video card support the HDMI CEC (Consumer Electronics Control) protocol? If not, the library libCEC is available for a Pulse-Eight USB-to-CEC adapter, which might do the job in your case.
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$ eix libcec
* dev-libs/libcec
     Available versions:  2.1.3 (~)2.1.4 (~)2.2.0 {cubox debug exynos raspberry-pi static-libs xrandr}
     Homepage:            http://libcec.pulse-eight.com
     Description:         Library for communicating with the Pulse-Eight USB HDMI-CEC Adaptor
More information is available in the KODI Wiki article on CEC.

Interesting adapter nice to know it exists. So its the HDMI port in the video cards that are not typically not supporting the CEC (Consumer Electronics Control)?

Fitzcarraldo · Post by **Fitzcarraldo** » Thu Dec 11, 2014 7:52 pm

turtles wrote:So its the HDMI port in the video cards that are not typically not supporting the CEC (Consumer Electronics Control)?

Yes, although I don't know about the latest models. Surprisingly, a lot of HTPCs do not support CEC (see http://kodi.wiki/view/CEC#CEC-capable_HTPCs). So, if you want to be able to use CEC, be sure to ask the manufacturer of the video card (or HTPC, or box-PC) if the HDMI port supports CEC. See https://en.wikipedia.org/wiki/HDMI which gives a detailed explanation. CEC is on HDMI Pin 13 (Pin 14 on Type C connector, Pin 15 on Type D connector).

Wikipedia wrote:Consumer Electronics Control (CEC) is an HDMI feature designed to allow the user to command and control up-to 15 CEC-enabled devices, that are connected through HDMI, by using only one of their remote controls (for example by controlling a television set, set-top box, and DVD player using only the remote control of the TV). CEC also allows for individual CEC-enabled devices to command and control each other without user intervention.[65]

It is a one-wire bidirectional serial bus that is based on the CENELEC standard AV.link protocol to perform remote control functions. CEC wiring is mandatory, although implementation of CEC in a product is optional. It was defined in HDMI Specification 1.0 and updated in HDMI 1.2, HDMI 1.2a and HDMI 1.3a (which added timer and audio commands to the bus). USB to CEC adapters exist that allow a computer to control CEC-enabled devices.

turtles · Post by **turtles** » Thu Dec 11, 2014 9:40 pm

Interesting I see that wiki links to this page:
http://www.intel.com/support/graphics/sb/CS-034397.htm
Buried under this question:
What are the differences between different HDMI versions?
It says Intel does not 'support' CEC

I wonder what does that mean? All actual Intel Graphics chips would need to have had something designed in and they omitted it or the Intel driver people don't want to be bothered with implementing the protocol?