So I had some initial success with the Raspberry Pi and using soundmodem as a software TNC for APRS packet radio. The success seems to have been short-lived.
I am able to decode packets from test wave files that I’ve been using, but the APRS over the air does not appear to be working! For a short period of time, I was able to decode APRS packets with little problems, and then when I moved the Pi to a more convenient location on my work bench (requiring a power-cycle) everything stopped working.
Troubleshooting is what I do for a living, so I’ve been through all of the standard check-lists – I’ve even verified drive levels, etc. and have been left without any success! What really gets me is that even with a full-fledged computer which has MIPS to spare, I am no longer able to decode any real-world packets.
I’ll be scoping the AFSK output of the radio to check the “flatness” of the 1200 and 2200Hz tones (they should be of similar amplitude, ideally). If the AFSK signal turns out to be okay, I’ll really be confused ..
Well, fingers crossed for now …