I have my Core connected via usb and currently just running Tinker while I play around. Usually it can stay connected for a day or so before it loses connectivity and requires a Factory Reset to connect again.
I managed to catch it in the act of disconnecting one night and the light combination looked like this:
Breathing Cyan
Flashing Cyan (10 sec)
Flashing Red (3 cycles, less than a second)
Flashing Cyan (~5 secs)
Flashing Green
It would stick on flashing green until a factory reset was performed. After the factory reset I am sometimes able to reconnect using the Spark CLI, sometimes it requires more than one reset to get it connected.
Is this combination of lights a clue as to what’s going on?
The flashing red means that it was unable to connect to the cloud. This might be due to a network connectivity error.
The flashing green means that the device has lost it’s DHCP assigned internet address and is trying to obtain a new one from the router. (So clearly the device isn’t able to connect to the internet - vis a vis the network connectivity error mentioned above.
This could be caused by the router reclaiming the core’s IP address and the core unable to reclaim another one. Perhaps check your DHCP lease time on the router?