For TNC, I’m using direwolf combined with
DRA-34 (cm108 GPIO)
Signalink USB (VOX)
or a Cheapo $8 USB sound card plus USB to Serial for RTS-based keying.
I’ve used each of these sound cards with both the Rock64, Pi3/4, and Chromebook.
I’ll consider writing up a blog post with more details on my setup.
-Masen KF7HVM
