I’m working on a project to have my ceiling light/fans work with homeassistant. They work on a sub-GHz band. I scanned each of the room’s remotes and have them all cataloged.
I now have the task of finding a module for the Arduino that can broadcast to 304.25—next, coding it up to work with homeassistant. Then I’ll keep it central to all the rooms to broadcast events.
Another challenge is keeping state. So I’d have to have commands to set the state and to watch for the frequencies used for the remotes to toggle the state of the light/fan that was just turned on or off.