In an Android app that we created for a project (a step-counter fitness tracker), we require user authentication to access the user's data in Firebase. Same goes for the Python program in the Raspberry Pi.
However, I prefer to capture data from the LSM303 sensor connected to the Pi (which will show it to a tiny display that's also connected to the Pi), and send it to the phone, which will send it to Firebase (instead of having the Pi connect to the Firebase and authenticate), but I never got to figure out how to do it.
usb0 entry in
allow-hotplug usb0 iface usb0 inet dhcp
I tried setting up a USB tethering, but it won't start.
$ sudo ifup usb0 ... Cannot find device "usb0" Failed to get interface index: No such device ... ifup: failed to bring up usb0
Raspbian info (if it helps):
$ lsb_release -a No LSB modules are available. Distributor ID: Raspbian Description: Raspbian GNU/Linux 9.8 (stretch) Release: 9.8 Codename: stretch