This is better than using RAM, as it keeps the state between power
cycles...

The old method would introduce a race condition where the buffer
could be overwritten before the data was consumed.  For slow, single
character typing this was fine, but w/ packets being generated by
a computer, this would cause corruption of the incoming data..

a lot more will need to be added as we go on..

This was pulled from heltec's PingPong example, but all licenses
are free..  Also, the files were cleaned up, that is CRs removed,
and trailing white space removed from lines...