I am looking to build a smart device with no external controls (no buttons, display, etc.) and am trying to figure out how to most easily allow a user to supply Wifi configuration to it.
A specific device that comes to mind is the Chromecast; to configure this device, a user simply goes to a URL (something like
chromecast.com/setup) and is able to configure the device from there. How is something like that implemented on a technical level? The site must redirect to a local I.P. or something, but that wouldn't make sense because there is no guarantee that the device has any specific I.P.
In short, I am looking for a description of how such a feature on something like the Chromecast is implemented.