I am running LMS on a hifiberry with a RPI 3. I would like to attached a keyboard so that I can pause music. I use iPeng on the my phone and my desktop is hosting the server, so I can start and stop from either of those devices, but I want to have something physical on the device (Which is connected to a DAC then to a vintage pre-amp with no remote control). I need to go over to the system to change the volume so it is not inconvenient for me.
The idea about the keyboard is not really about the keyboard. If I could get the keyboard to work, I will figure out a way to create a very small box with play/stop buttons on it, and just bind those to the specified keys.
You can use the Jivelite GUI in autostart to control those basic features. You can also use the GPIO-pins and rotary encoder or button to bind commands like play or pause directly.