airPy link protocol is used at the moment for configuration and tuning purpose only.
It is a variable size serial protocol used for the data communication between the pyboard and the Ground Station.
The idea is to use this protocol not only on the USB but also on Wi-fi, Bluetooth and ad hoc RF channel (e.g. 433MHz)
Each APLINK message consists of a header and a variable size payload (depending on the content) as specified in the following schema.
