Captive Portal to change wifi settings of Raspebrry Pi

Hi,
I’m asking for couriosity and because I’m thinking about installing home assistant.

When I set up the RPi in my network. How can I port it to another network ( e.g. to a freinds house ) ?
Is there something like a captive portal AP that I can trigger with a GPIO input to change wifi settings and after restart connect to that network?

Would aprecciate any suggestions on how to do that.
HA is a great project !!

Manuel

You want to unplug your Pi and move it to another LAN ? your own or someone else’s?
If that’s all you want just store the network IDs and Passwords for the WiFi networks you want to connect to and it will just auto-connect if setup correctly. This can be done uber-easy in the command line in Raspbian (or Raspberry PI OS as it is called now). https://raspberrypihq.com/how-to-connect-your-raspberry-pi-to-wifi/#:~:text=Configuring%20your%20WiFi%20network,conf.&text=Remember%20to%20replace%20this%20with,Ctrl%2BX%20followed%20by%20Y.

OK, this would be OK. But what if a user with no experience changes his WLan Password for any reason.
In this case I would like them to be able to set credentials in an easy way without logging in to the OS.
Is there any possibility?

Thanks.