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Keychron keyboards on Linux + Bluetooth fixes

Here is the best setup (I think so :D) for K-series Keychron keyboards on Linux.

Most of these commands have been tested on Ubuntu 20.04 and should also work on most Debian-based distributions. If a command happens not to work for you, take a look in the comment section.

Make Fn + F-keys work

Keychron Keyboards on Linux use the hid_apple driver (even in Windows/Android mode), both in Bluetooth and Wired modes. By default, this driver uses the F-keys as multimedia shortcuts and you have to press Fn + the key to get the usual F1 through F12 keys.

In order to change this, you need to change the fnmode parameter for the hid_apple kernel module. Here's some documentation on it, but a quick summary can be found below:

  • 0 = disabled: Disable the 'fn' key. Pressing 'fn'+'F8' will behave like you only press 'F8'
  • 1 = fkeyslast: Function keys are used as last key. Pressing 'F8' key will act as a special key. Pressing 'fn'+'F8' will behave like a F8.
  • 2 = fkeysfirst: Function keys are used as first key. Pressing 'F8' key will behave like a F8. Pressing 'fn'+'F8' will act as special key (play/pause).

You can temporarily set the value (for testing, for example) by doing:

# replace <value> below with 0, 1 or 2
# example: echo 2 | sudo tee /sys/module/hid_apple/parameters/fnmode
echo <value> | sudo tee /sys/module/hid_apple/parameters/fnmode

Test how the keyboard behaves after each value. Pick the one the works for you. Once you have found the value that works for you, you can make the change permanent:

  1. Create the file /etc/modprobe.d/hid_apple.conf
  2. Add this line to the file: options hid_apple fnmode=<value>, replacing <value> with the one that worked for you in the previous step (0, 1 or 2)
  3. Save the file
  4. Run sudo update-initramfs -u
  5. Reboot

Here's a script, for convenience:

# replace <value> below with the one that worked for you in the previous step (0, 1 or 2)
# example: echo "options hid_apple fnmode=2 | sudo tee /etc/modprobe.d/hid_apple.conf"
# this will erase any pre-existing contents from /etc/modprobe.d/hid_apple.conf
echo "options hid_apple fnmode=<value>" | sudo tee /etc/modprobe.d/hid_apple.conf
# the "-k all" part is not always needed, but it's better to do that for all kernels anyway
sudo update-initramfs -u -k all
sudo systemctl reboot

If get stuck with numpad mode: Double hit F6 or fn + F6.

Enable Bluetooth fast connect config:

If your keyboard takes too long to connect to your computer over Bluetooth (for example, when you press a key and wakes it up), you can enable the Bluetooth fast connect. This usually makes the keyboard connect in less than 1 second.

Some users have reported issues with Bluetooth headphones such as popping audio and general instability, but I haven't experienced anything like that.

  1. Edit the file /etc/bluetooth/main.conf
  2. Uncomment FastConnectable config and set it to true: FastConnectable = true
  3. Uncomment ReconnectAttempts=7 (set the value to whatever number that you want)
  4. Uncomment ReconnectIntervals=1, 2, 3

Disable Autosuspend for USB Bluetooth dongles:

If your keyboard just won't reconnect after sleep, it might be because your Bluetooth card or dongle was automatically suspended by the operating system. You can disable the auto suspend feature for USB Bluetooth dongles by changing the settings for the btusb module.

Note: you might need to target a different module if your Bluetooth controller is somehow using some other module. The options and values themselves might change as well. You need to check the documentation for the module your Bluetooth controller uses. Most USB Bluetooth dongles (and sometimes internal cards that are wired to the USB bus) use btusb. Please check if the btusb module is used by your controller first.

# Disable autosuspend for btusb to make the bluetooth keyboard work again
# this will erase any pre-existing contents from /etc/modprobe.d/btusb_disable_autosuspend.conf
echo "options btusb enable_autosuspend=n" | sudo tee /etc/modprobe.d/btusb_disable_autosuspend.conf
sudo update-initramfs -u

Now reboot your computer, or run:

sudo modprobe -r btusb
sudo systemctl restart bluetooth
sudo modprobe btusb

Enable Bluetooth after waking up from sleep:

When your computer wakes up from sleep mode, the Bluetooth controller might not turn on automatically. In order to force it to do so, we can create a script that will be executed every time the computer comes back from sleep mode.

Note: just like in the previous step, this script assumes your Bluetooth controller uses the btusb module.

# Unload the btusb module, restart the bluetooth service and reload the module again
# post = after the computer wakes up
sudo tee /lib/systemd/system-sleep/bt << EOT
case $1 in
    modprobe -r btusb
    sleep 1
    service bluetooth restart
    sleep 1
    modprobe btusb
# Now let's make the script executable
sudo chmod +x /lib/systemd/system-sleep/bt

Other resources

If the steps above haven't done it for you, try checking kurgol/keychron. Currently, it only mentions K2 and K6 keyboards, but the tips should work for most Keychron boards.

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Thanks. Confirmed on a thinkpad z13 with ubuntu 22.04 and keychron k8.

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Looks like ubuntu lts 22.04 5.15 kernel has this patch backported ( So setting fnmode to 3 works. But for some reason it's not the default.

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kespineira commented Nov 7, 2022

Hi! I'm trying to connect my K6 by bluetooth but not once it establishes the connection it disconnects instantly. I'm using Ubuntu 22.04.

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Sorted a lot of problems for me on Keychron K3

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sudo mkinitcpio -P can be use for arch based system instead of sudo update-initramfs -u

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gavingc commented Nov 17, 2022

Success & Thanks to Everyone

Keychron K4V2 on Debian 11 (11.5 Bullseye) w/Keychron Firmware

Out of the box, fnmode reported as 1 by:
cat /sys/module/hid_apple/parameters/fnmode

fnmode = 0 or 2 (I chose 2 but both seemed to work the same)

Keyboard switches: Windows/Android, Bluetooth or Cable.

As per included instructions, press "fn + x + l" keys together for 4 seconds.
(until keyboard lights flash; yes lower case works)
This toggles between Multimedia Keys and F1-F12 as first layer.

Caps Lock LED is red only and works as expected.

Num Lock LED is red only and works as expected, but it is possible to get into a state where it is always-off by playing with the NumLock on laptop keyboard or Plasma Startup settings.
Personally, I'd like an always-off state that was reliable as I have the OS force Num Lock function on, so don't need the red LED amongst my chosen RGB.
In either case the Num Lock key still works as expected.

Keyboard 'model' used: Generic 105-key PC (intl.).
Keyboard layout: us.

Fn + F5 adjusts RGB brightness down.
Fn + F6 adjusts RGB brightness up.
Fn + lamp key toggles RGB on/off and keeps brightness setting.

Would be fantastic to see QMK fully support these keyboards + Bluetooth - fingers crossed!

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Raremaa commented Dec 13, 2022


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My hero, thank you for this, i was already a bit disaaspointed that my keyboard was not working as expected in the first time but you saved my day! Thank you!

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Thank you so much! It worked on my Keychron K2 with Ubuntu 18.04.6!

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Thank you! It worked on Debian 11 Bullseye

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Thank you, it worked on Debian 11!

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hughesjs commented Jan 21, 2023

I'm having an issue where my K8P will pair with the laptop then immediately disconnect and won't connect again... Any ideas?

Not really sure where I'd even start debugging it

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I'm having an issue where my K8P will pair with the laptop then immediately disconnect and won't connect again... Any ideas?

Not really sure where I'd even start debugging it

The K8 Pro is an entirely different beast. It's based on a fork of QMK with some Keychron-specific code (if it hasn't been upstreamed yet). I'd recommend you try to look up information on Bluetooth on QMK boards and the issue you're having.

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hughesjs commented Jan 21, 2023

@andrebrait - Gutted, cheers though

Might be worth putting a note in the Gist that it doesn't apply to the K8P

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dmkur commented Feb 5, 2023

Thank you so much!
F1-F12 are working perfect!

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kpwhit commented Feb 7, 2023

The Bluetooth fast connect fix worked great! Was taking several seconds to reconnect after sleep, now it's just as quick as it is on Windows. Thanks for this fix!

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hughesjs commented Feb 7, 2023

I'm having an issue where my K8P will pair with the laptop then immediately disconnect and won't connect again... Any ideas?

Not really sure where I'd even start debugging it

For anyone who does have a similar issue... I updated to the latest version of the QMK firmware and that seems to have resolved the issue, whatever it was.

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Thanks a lot! (:

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Hi guys,

How to use the print screen?

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mr337 commented Feb 22, 2023

Option 2 fixed my issue, Keychron K5 on Ubuntu 22.04

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Tengo un problema en el que mi K8P se empareja con la computadora portátil y luego se desconecta inmediatamente y no se vuelve a conectar... ¿Alguna idea?

No estoy muy seguro de dónde comenzaría a depurarlo

Were you able to solve the problem? The same thing is happening to me with a k3 v2.

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Hi guys,

How to use the print screen?

As usual - there is a separate PrintScreen button on the right top corner (works normally)

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hughesjs commented Mar 7, 2023 via email

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My Keychron K8 had connectivity issues with Bluetooth when connecting to my Linux/Windows PC, but not on my MacBook Pro. My symptoms were choppy connection several times an hour, connection taking a while after the keyboard goes on suspend, repeated key presses likeeeeee thisssss. Enabling fast connect fixed ALL my issues on Linux. Thank you! 👍

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ZANX3Y commented Mar 31, 2023

Never would have figured it out on my own. Thank you!

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flooijdt commented Apr 1, 2023

In OpenSUSE with KDE, the main.config file is located at /usr/share/doc/packages/bluez. In OpenSUSE with GNOME, it is in the same directory as related in this gist (/etc/bluetooth/).
Thanks a lot for the gist! This bluetooth problem was getting on my nerves!

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Just to point out: On Debían 11.6 my Bluetooth connection to my K2 keyboard wasn’t stable between reboots and many times I had to reconfigure it.

Enabling AutoConnect and FastConnect as per the instructions above fixed it. It takes however 5 to 10 seconds to connect but I am a patient man.

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mttkay commented Apr 21, 2023

Just a side note that this will work with any keyboard that uses the hid_apple driver not just Keychrons. I use the fnmode module setting for my NuPhy Air as well to turn on F-keys by default.

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Katharta commented Jun 1, 2023

Wow, FastConnectable = true made such a huge difference. I no longer have to fumble with switching the keyboard off and on over and over until it reconnects. Thank you for sharing this!

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