Okay, there are home automation nerds here, right?
I *think* I want home assistant as software?
Tell me (concretely) what hardware to get:
1. easily available in Germany
2. no proprietary hard/software connected to wifi or ethernet
3. priority right now is controlling heating, so thermostats, sensors for windows…?
Especially 2 overwhelms me, but is a hard requirement. A lot of devices say they need a BrandName® Hub and it's not obvious to me whether I could replace that with a free alternative.