Alright, spent a bunch of hours coding.  As typical of coding, some things went easy, some were worthy of tearing my hair out over.  I finished and tested the LCD driver chip emulation including indexing and loading actual display data to an array.  I also wrote and debugged the subroutine to recognize both number and letter data from the individual 7 segment signals and turn it back into numbers and letters (some is not possible, such as “5” vs “S”).

I finally had enough for the day and called it quits.  I am now able to read out and display the radio frequency and channel like this:

The bottom line is some diagnostic info I no longer need.  This is a big deal!  With all the command and data properly read out, most of the hard part is already behind me now.

One weird thing though, and I have no idea what’s up.  Previous to today, the data receive routine would update on each packet received.  But now, it only runs once.  It runs properly, but only once!  I tried commenting out large sections of code to no avail.  I may have to post my code to Stack Exchange and ask if anyone has encountered this before or has any hints.  I don’t mind posting it since I will open source it to GitHub when I’m done anyway.  I don’t think my rusty coding will be too embarrassing, ha ha.

While attempting to debug this problem I put statements which turned on and off an output pin so I could observe it on a scope.  This also allowed me to time certain sections of code, and I was curious about how fast the C code ran.  It turns out, respectably fast: my command decoder and data retriever, dozens and dozens of instructions, takes a grand total of 62 microseconds to execute.  As for size, with the libraries my code right now stands at about 15% of the available space on the chip.  Not too bad, these parts have pretty decent capability both in speed and size of program you can fit into them.