how to make lxqt use "fn" button

Student of UNSRI · 2025-12-31 15:37:26

can anyone tell me how to make lxqt use "fn" button to increase or decrease volume and brightness also for media control,like music on audacious.

thank you

seth · 2025-12-31 16:55:35

The Fn button itself is typically implemented in hardware and you won't be able to intercept it.
If you mean Fn+some key, first check the key

xev -event keyboard

and press the desired key.
If all you get is a KeymapNotify event that means the key is currently bound to something already, just that something isn't doing its job.
You can assign shortcuts to commands in the lxqt config center, https://wiki.archlinux.org/title/LXQt#Configuration

Student of UNSRI · 2025-12-31 21:38:45

i already test using "xev -event keyboard", but the output us very strange,because when i press button combination for decrease brightness,up/down volume,and media controller(pause,resume,next,etc with fn+home/pg up/pg down/end) on xev, the output is :

KeymapNotify event, serial 45, synthetic NO, window 0x0,
    keys:  187 0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0

but for increase brightness. the output is :

MappingNotify event, serial 36, synthetic NO, window 0x0,
    request MappingKeyboard, first_keycode 8, count 248

KeyPress event, serial 36, synthetic NO, window 0x3000001,
    root 0x3bb, subw 0x0, time 28185232, (409,299), root:(446,373),
    state 0x0, keycode 248 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 36, synthetic NO, window 0x3000001,
    root 0x3bb, subw 0x0, time 28185232, (409,299), root:(446,373),
    state 0x0, keycode 248 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

MappingNotify event, serial 36, synthetic NO, window 0x0,
    request MappingKeyboard, first_keycode 8, count 248

KeymapNotify event, serial 36, synthetic NO, window 0x0,
    keys:  187 0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0

for the volume button (fn+f9/f10/f11) is work (don't ask me how it work,i also didn't know),but the output on xev is

KeymapNotify event, serial 26, synthetic NO, window 0x0,
    keys:  187 0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0

for note,after read the lxqt configuration for brightness,i testing the brightnessctl and xorg-xbacklight,but still didnt work

Last edited by Student of UNSRI (2026-01-01 05:15:15)

seth · 2025-12-31 23:24:51

Please use [code][/code] tags. Edit your post in this regard.

but for increase brightness

KeymapNotify event, serial 45, synthetic NO, window 0x0,

means that the key is currently bound to some action

MappingNotify event, serial 36, synthetic NO, window 0x0,

Do you use several keyboard layouts?

  state 0x0, keycode 248 (keysym 0x0, NoSymbol), same_screen YES,

https://wiki.archlinux.org/title/Map_sc … o_keycodes
There's probably also a message in the system journal/dmesg about the unknown key

Arch Linux

#1 2025-12-31 15:37:26

how to make lxqt use "fn" button

#2 2025-12-31 16:55:35

Re: how to make lxqt use "fn" button

#3 2025-12-31 21:38:45

Re: how to make lxqt use "fn" button

#4 2025-12-31 23:24:51

Re: how to make lxqt use "fn" button

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