The use case is this: the Pi will periodically ping my server. If it gets the go-ahead, it will perform some action using a relay. Otherwise it'll remain dormant.
I need to install multiple RP3s at multiple locations. I don't know what the WiFi passwords are until I get there and I'd rather not lug around an entire set of screen+mouse+keyboard.
Can't SSH into it until it's connected to the WiFi though.
What's the easiest way to have the Pi connect to an unfamiliar network without a screen/keyboard?
I was thinking maybe I can save the network name / pass in a USB file and, on boot, if there's no internet, check USBs for these files and attempt a connection.
The downside is that I'll have to have one USB per "installed" Pi.
I'm puzzled. Any ideas?