Re: Lenovo E16 Gen1 with Intel Iris adjust brightness, get Fn-Keys working

[Tixy <tixy@yxit.co.uk>]

On Tue, 2023-10-24 at 09:32 +0200, basti wrote:
> 
> OK, I can write the values ​​to 
> /sys/class/backlight/intel_backlight/brightness
> 
> The default is 15040, which seems to be the maximum.
> Nothing visible changes between 15040 and 13000.
> 60 is very dark.
> It therefore looks like an exponential function.
> 
> I have to see how I can represent this in a function to use it with the 
> fn-keys.
> 

You can edit ~/.config/openbox/lxde-rc.xml

Here's my full notes from when I did what your trying to do on a laptop
many years ago. This obviously needs modifying for your machine...

0. Edit /etc/rc.local to add

	# make brightness writeable
	chmod a+w /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight/brightness
	# set brightness to a nice default
	echo 1200 >/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight/brightness

   The make file executable

	chmod a+x /etc/rc.local

   UPDATE: rc.local now needs a shebang at the top, i.e. #!/bin/sh

1. Create /home/tixy/bin/bl- to reduce brightness in steps

	#!/bin/bash

	device="/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight"
	step=200
	curval=`cat $device/brightness`
	newval=`echo $(expr $curval - $step)`
	if [ $newval -le $step ]; then
	  newval=$step
	fi
	echo $newval
	echo $newval >$device/brightness

2. Create /home/tixy/bin/bl+ to increase brightness in steps

	#!/bin/bash

	device="/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight"
	step=200
	curval=`cat $device/brightness`
	maxval=`cat $device/max_brightness`
	newval=`echo $(expr $curval + $step)`
	if [ $newval -ge $maxval ]; then
	  newval=maxval
	fi
	echo $newval
	echo $newval >$device/brightness

3. Edit '<keyboard>' section of ~/.config/openbox/lxde-rc.xml

    <keybind key="XF86MonBrightnessUp">
      <action name="Execute">
        <command>/home/tixy/bin/bl+</command>
      </action>
    </keybind>
    <keybind key="XF86MonBrightnessDown">
      <action name="Execute">
        <command>/home/tixy/bin/bl-</command>
      </action>
    </keybind>