Does anyone know how I can send messages between my macropad and RGB keyboard? I have my macropad set up with four layers that are selected with the top row of smaller keys. When I switch between the layers it would be nice if the keyboard also switched layers at the same time.
I read something about virtual serial ports, but not sure how I would go about setting up serial communication between the devices.
I don’t think USB devices can send arbitrary messages directly with each other. Or at least standard HID keyboards don’t have that option.
I believe you have a couple options.
Having a helper app / script running on your OS that will pass along messages. Not ideal imo.
Using a trick, something not intended for passing arbitrary messages.
The one way a standard HID keyboard can communicate with other keyboards is with the HID keyboard indicators for CapsLock, NumLock, ScrollLock, Kana. Your OS automatically passes the status to any connected HID keyboard. And a forum member made FWL16 keyboard firmware using very quick toggles of the indicators to pass messages. You could adapt that to send layer changes.