Bruce,
Here is the link to the material that references the second Nano.??
In that post, he does provide the link to the software for the second Nano.? Also, note that the first Nano has to run different software as well.? For the main Nano (the one mounted on the Raduino board) here is the GitHub link:
Note that the correct version for the v6 is the v5 files.? Also, note that the correct version for a two Nano system ends in _S.? There is a text file in the zip files that give the which file to us information.
We who use his software owe a lot to KD8CEC for all the work he has put into this fantastic system.? I would agree that it is really difficult to follow and find all of the information on his blog.? I have been doing so for 2 years now and still have problems remembering and finding the correct information.
Hope the above information helps you find what you want/need.
73
Evan
AC9TU