Smart LCD birght/dim...

Nick Guenther kousue at
Sat Apr 12 04:43:35 CEST 2008

On Fri, Apr 11, 2008 at 8:50 PM, "Marco Trevisan (Treviño)"
<mail at> wrote:
> Since Freerunner won't have an hardware light sensor to set its LCD
> brightness, I got some ideas about smartly changing the luminance of the
> GTA02 screen to save its battery (still with an unknown life time :/).
>  Of course they aren't and never will be precise as an hardware sensor is,
> but it's the only thing we have:
>  1) Setting the brightness following the hour of the day: also if the phone
> can't know if it's sunny or cloudy, neither if you're indoor or outdoor,
> it's clear that just knowing the hour of the day, the date and your latitude
> (to be set once via GPS) the phone can easily know when the sun will rise
> and set, and so it will be possible increasing or reducing the LCD
> brightness.
>  Also if you're indoor, I guess that when the sun is "gone" you won't need
> so much luminance...
>  2) Using personal profiles that follow your habits: you could define, for
> each hour of each week day the "presumed" luminance, using something like a
> calendar. I mean, if on working-days I generally stay indoor every day from
> 8:30 to 13:00 and from 15:00 to the 19:00 I figure that on these intervals I
> don't need all the LCD power, so I'll set in my "calendar" that on such
> interval I'll be indoor...
>  I guess that many of you would follow a routine durning the week, why don't
> educate your phone for it!?
>  3) Setting the luminance following the weather. Of course I've no light
> sensors, neither a barometer :P, but if I've a working connection available
> I could use the weather data downloaded every few minutes (60, for example)
> from internet to change my screen brightness (of course merging these
> informations with points 1 and 2)
>  What do you think about them?
>  I do think that they are really simple to implement, and that also if they
> won't guarantee a perferct result, they could be a "smart" workaround.
>  --
>  Treviño's World - Life and Linux

Or you could just... dim it after a few seconds and go blank after a
minute like every other phone does. If we try to solve this by complex
heuristics we're
1) going to get it wrong
2) going to end up wasting more battery in doing the computations than
we save by them.


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