I am trying to use an old Logitech USB keyboard to control keyboard macros on my new Macbook Pro (OS Sonoma 14.6).
Unfortunately, Keyboard Maestro does not respond when I select the option "USB device key trigger". When I select "Hotkey Trigger" it can't differentiate between my computer keyboard and the USB device.
What I'd like is to have the USB keyboard activate hotkeys without it activating keys on my native mac keyboard. (For example, "G" hotkey does not type G but types the keystroke activated through keyboard maestro)
I hope this is clear? Would appreciate any and all help...
There's a chance that I'm wrong, or partly wrong, but my advice is free, so don't complain too much.
Each USB device on a Mac, like your keyboards, generates USB events in macOS. These events do not have a "device name" attached to them, so a "G" is the same signal regardless of which keyboard device it came from. Therefore KM cannot distinguish.
However there are two ways to solve this, I think.
First, I believe there is software out there that can use low level device driver changes to distinguish between different devices. For example, I think Karabiner Elements can distinguish the difference between keyboards. In that case, you could get it to change the event for a key on your external keyboard to some unused USB event on your Mac. For example, you might assign "G" on your external keyboard to "Number Keypad Clear Key" (which you probably don't have on any MacBook) and then Keyboard Maestro could use that event to react to the external keyboard only. It would take a few hours to manually remap all the external keys by hand. But it's doable. Just bear in mind that Karabiner is probably using undocumented APIs, so you are taking chances relating to reliability.
Alternatively, if your external keyboard is a programmable keyboard, you won't need Karabiner because the software that comes with your external keyboard should have the ability to tell your keyboard that the key "G" should be mapped to some other USB event. Again, it will take a few hours to manually remap all those external keys.