adb - touretzkyds/cozmopedia GitHub Wiki
adb (Android Debug Bridge) must be installed in order for Linux to talk to the phone or tablet running the Cozmo app via the USB cable. See the installation instructions on the Cozmo SDK site.
Use the shell command adb devices
to verify that Linux can see the phone/tablet.
If a device is shown but instead of a serial number it says "Unauthorized", you need to turn on debugging on the phone/tablet. This can be done via the Settings menu, under Device Options.
If no device is shown, you may need to restart the adb server. Do this in a shell:
$ adb kill-server $ adb usb