Turning off screen in Linux

[Linux for blind general discussion]

Tim again.  There are multiple factors that go into it:

- the size of the screen

- the brightness of the screen

- how long it's on

An extra 20 minutes is an extra 20 minutes.  Or maybe going screenless
gets you more like hours of savings.  Either way, if you don't need
it because you have audio/braille as your output interface, turning
off the screen completely is 100% free battery savings.

I know with my phone, when I'm using the screen a lot, the battery
has usually dropped to around 40% when I put it on the charger for
the night.  When I'm using it mostly screenless (podcasts & calls),
it's usually more like 60% when I put it on the charger.

-tim

On 2022-10-18 16:12, Linux for blind general discussion wrote:
> Does turning off the screen make that much of a difference to battery life
> actually? I'm unsure since I've heard so many claims over the years of it
> does, it doesn't, it does but only this much, etc
> 
> 
> On 10/18/22 15:01, Linux for blind general discussion wrote:
> >Tim here.  I believe xrandr should let you do this.  First, you
> >need to get the name of your display according to xrandr:
> >
> >   $ xrandr | awk '/primary/{print $1}'
> >   LVDS-1
> >
> >For me that's "LVDS-1" but your output might be different, like
> >"VGA" or "HDMI-1" or something.
> >
> >You should then be able to disable/power-down that display with
> >
> >   $ xrandr --output LVDS-1 --off
> >
> >If you need to re-enable it for whatever reason, change the "off"
> >to "auto":
> >
> >   $ xrandr --output LVDS-1 --auto
> >
> >I'm not sure how this interacts with screen-readers, and based on
> >my testing, it feels like applications might go a little weird,
> >getting resized to an itty-bitty size (I think my texting xterm got
> >resized down to fit in a 320x200 display, since it was shrunk down
> >when I re-enabled the screen).
> >
> >If it's a problem for you, there might be a way to create a
> >virtual monitor, by including something like
> >
> >   SubSection "Display"
> >     Depth 24
> >     Virtual 1024 768
> >   EndSubSection
> >
> >in the "Screen" section of your xorg.conf file.  X should then think
> >you have two displays connected to your system, and you can use the
> >`xrandr ... --off` command to turn off the real one while still
> >having the virtual one of a size large enough to make X programs
> >happy.
> >
> >Or possibly run "xvfb" to create a virtual X environment, possibly
> >adding the physical display to its configuration, and then using
> >xrandr to disable the real screen?
> >
> >Just a few ideas,
> >
> >-Tim
> >
> >On 2022-10-18 07:41, Linux for blind general discussion wrote:
> >>Hello everyone,
> >>
> >>Ubuntu Mate 22.04 64-bit.
> >>
> >>
> >>I suppose there are multiple ways to go about turning off the laptop
> >>screen on Linux, from switches to more invasive configuration modifications.
> >>
> >>
> >>I wonder, what is the ideal solution for us to set up, so it would be
> >>possible to turn off the screen, so we could save battery, protect the
> >>displayed information etc. but we could at the same time switch the
> >>setting when necessary without the need to log out / restart?
> >>
> >>
> >>Thanks for your advices!
> >>
> >>
> >>Best regards
> >>
> >>
> >>Rastislav
> >>
> >>
> >>
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> 
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