Hyper Key + Fn Keys can't trigger change keyboard illumination

Describe the bug
I would like to be able to use the F1/F2 keys for their normal functions (Brightness Up/Down) when pressed alone, but map them to Keyboard Illumination Up/Down when pressed in combination with the hyper key. However, I cannot seem to get this to work, despite each part of the setup working correctly in other contexts. Not sure what I'm missing!

Since it seems BTT can't intercept media key presses, I have F-keys set to standard function keys in System Settings so I can fully remap them in BTT. Caps Lock is mapped to itself in System Settings, and set as hyper key in BTT.

I have successfully: used HYP to trigger other things (eg. window snapping), used F1/2 alone to adjust keyboard backlight, and used Shift + F1/F2 to adjust keyboard brightness when F1/2 are mapped to screen brightness.

I cannot get HYP + F keys to trigger keyboard brightness (any F key, not just F1/2). Nothing at all happens when I try to activate it. I also tried sending the shortcut through Shift + F1/2 since I knew that worked, but then it just asks me which action I'd like to perform.

Any ideas or help appreciated, thanks!

Affected input device

Only the shortcuts enabled in this screenshot function properly. All of them have the same settings as shown in the highlighted one, which is the one I'd like to actually work.

I have them shown like this only for illustration. In testing of course I don't have conflicting shortcuts enabled, and I've tried many combos of enabled/disabled just to make sure that isn't the issue. It isn't.

Device information:

  • Type of Mac: Macbook Air M2, 2022, 13.6"
  • macOS version: 14.3
  • BetterTouchTool version: 4.376

unfortunately I don't have a real solution to this. BTT recognizes the keypress fine and sends the illumination event to the system - but the system doesn't react. I assume BTT is at a too high level for modifying the caps lock to make it work with this special key (those system keys like keyboard illumination are pretty special)

You could workaround it by using @Frank1's trick of remapping capslock to a modifier instead of using it as a hyper key.
If you do this:

macOS will remap caps lock to the RIGHT control key. This means if you now record a shortcut using the remapped capslock and then activate the "differentiate left/right modifier keys" option, you'll basically have something similar to a hyper key - without BTT having to modify the caps lock events:

Appreciate the quick reply Andreas.

I have actually tried using the caps lock to right-control method, and interestingly it behaves just the same. I can pair it with an F key to do something else, and I can pair it with a non-F key to control keyboard backlight, but I can't both pair it with an F-key and control keyboard backlight.

Any other ideas for a workaround? I found this, which involves creating a custom LaunchAgent to remap the F5 and F6 keys, but I don't have the experience to be able to modify the script myself, and would rather not risk messing up other BTT functionality. I thought maybe a custom Apple Script, but it seems changing settings like that isn't as simple as I'd hoped.

If we're stuck on this for now its all good, I can just use a non-F key for the backlight :slight_smile: