[Lowfer] PSK31 audio beacon enhancement

[David Willmore]

> After you make your additions, please let us know where to download the
> schematics for the revised circuits.

The additon will be pretty simple.  I expect it to just be a Microwire
serial EEPROM tied onto the pins that are now used for the frequency/
offset selection.  Populate that 2x7 area with a mounting header and
the daughter card will just sit on that.  That gives me 7 pins on port
B to play with.  Serial clock, Data in, Data Out, and CS, are probably
all that'll be used.

I'll let everyone know when source and schematic is available.  It
may be through the NJQRP web site, so look there often. :)

Cheers,
David