ENH: Speed sensing the LoRa

[jschrempp]

On boot the Hub code will try communicating with the LoRa at 38,400. If it gets a bad response, then it will try at 115200. This will allow the hub to handle both LoRa devices used in the hub and factory new devices.

[BobGlicksman]

I think that this is a good idea, or else just leave hub LoRa modules at the default baud rate and only change the sensor board rate.