I am in the middle of setting up my home automation system with my Raspberry Pi (3B+), and I have a question regarding networking.
My Raspberry is running the Rasbian Lite derivative called Openhabian ( https://www.openhab.org/docs/installation/openhabian.html ). What I want to achieve is pretty simple. The raspberry is currently connected to my network using a LAN cable. But I want to move my home automation devices that don't need internet connection to completely separate network all together. So basically I'll set up a different wifi router and connect all of those devices to it. And I will not be connecting that router to my primary network. That way I can do anything with my primary network without breaking my home automation setup.
The idea of what I want is simple - the raspberry should connect to my primary network via a LAN cable, get it's IP from there (DHCP) and work like normal. But I also want to connect it to my home automation network via wifi at the same time. And it needs to be able to interact with devices from both networks at the same time.
Sadly I have almost 0 experience with Linux networking and I need some help on how to actually do this.