Our living room has three sets of curtains that already have a cord loop - so you can pull a cord to open or close them. You wouldd think it would be relatively easy to motorize this, by replacing the pulley on the wall at the bottom of the cord loop with a motor. These loops are located directly to a wall socket, so a mains powered option is fine.
However, I can mainly find systems that come with new rails and would cost several hundred euros per rail. Do any of you know a system that works in the EU (so 230v) and can be connected to home assistant?