setting screen brightness with special keys via keyboard, scan codes and what not

13 Jun 2022

      Support list,

doing some first steps on rather mobile systems a.k.a. notebook laptop
with leap 15.4 for example. Install went fine. Now digging into the
first real world situation and problems here.

machine vendor has some special keys on keyboard, so called and named
"FN" key, even fn-lock with small LED lighting up when setting the
lock FN function. Apparently there are no standards(?) for certain
advanced features such as turn up and down volume (speaker) or turning
up and down screen brightness and other fancy stuff :/

Coming a long way I remember keyboard scan codes ;) so then trying to
look that stuff up and how to use 15.4 kde desktop installation to
adjust the screen brightness.

In the power settings of the kde desktop there is a place where I can
adjust the screen brightness just fine via mouse and gui elements of
KDE. so far so good so the basic hardware driver of some kind to
adjust LED energy output and thus adjusting brightness of background
illumination and stuff works fine.

Then i tried to find  to adjust the shortcuts/keyboard shortcuts for
this feature. There is some KDE konfiguration dialog where it asks me
to press my desired key combination for examle for brightness and
volume of the speaker. Only it notices or gets told the wrong keyboard
sequences, it always only reports Fx function key values and reminds
me that many are already taken for other features and functions and if
I want to redefine those.

So wht now? Digging around on the net there are people that claim that
FN key at its own doesnt create a scan code but only will deliver
differing scan codes for those specialty keys though. But apparently
KDE doesnt get told or doesnt notices the differing scan codes or
something else is amiss?

where and how to use the special keys of todays hardware and what is
the reasoning behind? Apparently its not just that easy as a mere scan
code that gets created and sent to the software?

what I for example also noticed is that in the power settings, this
machine reacts just fine when closing the machines lid, but defining
the power button behavior just doesnt do anything. maybe thats a
special key in some ways as well, not wired via ATX or what other ways
such as in desktop ways and more :(

any isights? ty.

cagsm

jdd＠dodin.org

cagsm

jdd＠dodin.org

Robert Munteanu

jdd＠dodin.org

Robert Munteanu

Carlos E. R.

Andrei Borzenkov

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