I just pushed my latest code to main.  This has a working version of the AX25 Data Link State Machine.  You can see the code in AX25Task.c.  If you try to upload a file it will appear to work, with the ground station saying it was uploaded correctly.  All of the packets are received and Ack'd by PACSAT, but the Uplink state machine is not yet storing them in a file.  I still need to write that part.

To trigger the ground station you need to transmit the status of the uplink by typing:

send uplink status

This is also using 2m as the receive frequency.  Thanks to work by Jim, I have set this to use GFSK with BT=0.3.  BT is the shape of the bit shaping filter.  The filter may not be applied on receive, but setting it to GFSK vs GMSK makes a big difference.  It now receives well on 2m at 9600bps.  There is an errata from ON SEMI that says to use BT=0.3 vs BT=0.5 for transmit.

I have also implemented a mode change command.  You can type these commands in the console:

set rate 1200

set rate 9600

These will set the radios to the specified data rate.  You need to restart the processor to apply it.  We can probably just restart the radios, but that was a quick way to implement this for testing.