keyboard backlight doesn't work [Solved]

Issues Related to Hardware (Sound, Video, Printers, Scanners, Webcams, Touchpads, Keyboards, Sensors, Drives, GRUB, etc.)

Moderator: Moderators

keyboard backlight doesn't work [Solved]

Postby fjkhf » Mon Oct 21, 2013 18:45

Hello , I am using Sabayon KDE and I bought 'coolermaster devastator' keyboard which has backlight.
It supposes to work by pressing Scr key ,but it doesn't.

I went to System Settings->Input Devices ->Keyboard and it has an option

use keyboard LED to show alternative layout


and the backlight turns on and off when I change the layout!
Can I do sth to enable it by pressing a key?


Thanks!
fjkhf
Simple Hen
 
Posts: 97
Joined: Tue Jun 26, 2012 13:41

Re: keyboard backlight doesn't work

Postby Fitzcarraldo » Mon Oct 21, 2013 21:31

I'm not sure, but you could try creating a file /etc/X11/xorg.conf.d/00-keyboard.conf containing the following:

Code: Select all
Section "InputClass"
    Identifier "keyboard"
    MatchIsKeyboard "yes"
    Option "XkbLayout" "gb"
    Option "XkbVariant" ""
    Option "XkbOptions" "grp_led:num"
EndSection

That would presumably toggle the backlight when you press the Num Lock key, which is not ideal but better than the other key options (Caps Lock and Scroll Lock). The possible options that I know of regarding a keyboard LED are:

Code: Select all
grp_led              Use keyboard LED to show alternative layout
grp_led:num          Num Lock
grp_led:caps         Caps Lock
grp_led:scroll       Scroll Lock

You didn't indicate which language layout your keyboard uses. If your keyboard has a non-British layout then change the "gb" to the required layout code. For example, if your keyboard has a US layout, replace "gb" with "us".

If you already have a keyboard configuration file in the directory /etc/X11/xorg.conf.d/ then edit that instead of creating a new file. And if you have the file /etc/X11/xorg.conf with a section for the keyboard in it then try adding the option to that section instead.

All the possible XkbModels, XkbLayouts, XkbVariants and XkbOptions are listed in the text file /usr/share/X11/xkb/rules/xorg.lst.
User avatar
Fitzcarraldo
Sagely Hen
 
Posts: 7984
Joined: Sat Mar 10, 2007 5:40
Location: United Kingdom

Re: keyboard backlight doesn't work

Postby fjkhf » Mon Oct 21, 2013 22:07

Hello,

unfortunately it doesn't work..

The file 00-keyboard.conf exists and also the /etc/X11/xorg.conf exists.

I tried to add the Section "InputClass" ... to /etc/X11/xorg.conf but still the same..

The options
grp_led Use keyboard LED to show alternative layout
grp_led:num Num Lock
grp_led:caps Caps Lock
grp_led:scroll Scroll Lock


you gave me exist also in the system setttings as I wrote above but they refer only to alternative layout.You must choose first the
Use keyboard LED to show alternative layout
and then the button (num,scroll,caps) in order to do it.

Any other ideas?
Thank you
fjkhf
Simple Hen
 
Posts: 97
Joined: Tue Jun 26, 2012 13:41

Re: keyboard backlight doesn't work

Postby Fitzcarraldo » Tue Oct 22, 2013 13:26

Open a Konsole window, log in as root user, and see whether you have a keyboard backlight file in one of the sub-directories of the /sys/devices/ directory. For example, DuckDuckGo is telling me that the keyboard backlight on one model of Sony laptop can be switched on by issuing the command:

Code: Select all
echo 1 > /sys/devices/platform/sony-laptop/kbd_backlight

and off by issuing the command:

Code: Select all
echo 0 > /sys/devices/platform/sony-laptop/kbd_backlight

If you can find the relevant file (it might or might not be named kbd_backlight) in the Linux kernel system file system then the applicable commands could be tied to keyboard shortcuts in KDE.
User avatar
Fitzcarraldo
Sagely Hen
 
Posts: 7984
Joined: Sat Mar 10, 2007 5:40
Location: United Kingdom

Re: keyboard backlight doesn't work

Postby fjkhf » Tue Oct 22, 2013 13:55

Unfortunately I don't find any backlight file in the /sys/devices/platform folder..
fjkhf
Simple Hen
 
Posts: 97
Joined: Tue Jun 26, 2012 13:41

Re: keyboard backlight doesn't work

Postby Fitzcarraldo » Tue Oct 22, 2013 13:58

Yes, but have you looked in the other sub-directories in /sys/devices/? I.e. what other sub-directories are there in /sys/devices/?

Code: Select all
# ls -la /sys/devices
User avatar
Fitzcarraldo
Sagely Hen
 
Posts: 7984
Joined: Sat Mar 10, 2007 5:40
Location: United Kingdom

Re: keyboard backlight doesn't work

Postby Fitzcarraldo » Tue Oct 22, 2013 15:27

Or even other sub-directories in /sys/ (might be /sys/class/leds/ for example).

Additionally, I see that the X Windows command xset also has an option for LEDs. check the man page:

Code: Select all
man xset

There are various options for LEDs:

Code: Select all
[led {on|off}]

Code: Select all
[-led [integer]] [+led [integer]]


Code: Select all
led      The  led  option controls the keyboard LEDs.  This controls the
         turning on or off of one or all of the  LEDs.   It  accepts  an
         optional  integer, a preceding dash(-) or an 'on/off' flag.  If
         no parameter or the 'on' flag is given, all LEDs are turned on.
         If  a  preceding  dash or the flag 'off' is given, all LEDs are
         turned off.  If a value between 1 and 32  is  given,  that  LED
         will  be  turned on or off depending on the existence of a pre-
         ceding dash.  A common LED  which  can  be  controlled  is  the
         ``Caps  Lock''  LED.   ``xset  led  3''  would  turn led #3 on.
         ``xset -led 3'' would turn it off.  The particular  LED  values
         may refer to different LEDs on different hardware.
User avatar
Fitzcarraldo
Sagely Hen
 
Posts: 7984
Joined: Sat Mar 10, 2007 5:40
Location: United Kingdom

Re: keyboard backlight doesn't work

Postby fjkhf » Tue Oct 22, 2013 16:57

If I type
Code: Select all
xset led named "Scroll Lock"
the leds are turned on!But ,I can't turn them off.
I must type
Code: Select all
xset led named "Scroll Lock"
to turn them off.


Is there a way to accomplish that with a key?(scroll lock)

The
Code: Select all
ls -la /sys/devices
gives:

.
... ..
...breakpoint
...cpu
...LNXSYSTM:00
...pci0000:00
...platform
...pnp0
... rapidio
...software
... system
... virtual


Also , there are various "led" files in vatious subfolders inside sys.

Thanks for helping.
fjkhf
Simple Hen
 
Posts: 97
Joined: Tue Jun 26, 2012 13:41

Re: keyboard backlight doesn't work

Postby Fitzcarraldo » Tue Oct 22, 2013 17:43

fjkhf wrote:If I type
Code: Select all
xset led named "Scroll Lock"
the leds are turned on!But ,I can't turn them off.
I must type
Code: Select all
xset led named "Scroll Lock"
to turn them off.

I assume you forgot to quote the minus sign in the second command (to turn off the LEDs)?:

Code: Select all
xset -led named "Scroll Lock"


Is there a way to accomplish that with a key?(scroll lock)

Yes, there is. Several ways, actually. For example, you could create a simple Bash script along the lines shown below to toggle the backlight on/off, and set up a keyboard shortcut to launch it. In KDE you can set up keyboard shortcuts via e.g. 'System Settings' > 'Shortcuts and Gestures' > 'Custom Shortcuts'.

Code: Select all
#!/bin/bash
if [ -f /home/fjkhf/keyboard_led ]; then
   xset -led named "Scroll Lock" && rm /home/fjkhf/keyboard_led
else
   xset led named "Scroll Lock" && touch /home/fjkhf/keyboard_led
fi

If, for example, you created a script named /home/fjkhf/toggle_keyboard_backlight.sh then you would also need to enter the following command in order to make it executable:

Code: Select all
chmod +x /home/fjkhf/toggle_keyboard_backlight.sh
User avatar
Fitzcarraldo
Sagely Hen
 
Posts: 7984
Joined: Sat Mar 10, 2007 5:40
Location: United Kingdom

Re: keyboard backlight doesn't work

Postby fjkhf » Tue Oct 22, 2013 18:24

I have a problem , I can't bind scroll lock to script.

I created the script you gave me , it works if I execute it (turns on ,execute again and turns off).

I tried to go to Create custom shortcuts but I am not sure what is the right way.
I chose Konqueror Gestures -> New -> but from here whatever I tried I didn't find how to bind Scroll lock to the script.It doesn't give me an option.


Thank you!
fjkhf
Simple Hen
 
Posts: 97
Joined: Tue Jun 26, 2012 13:41

Next

Return to Hardware

Who is online

Users browsing this forum: No registered users and 1 guest

cron