Hallo people there at FriendlyElec

Allwinners Socs have a full stereo analog audio in and out

I encourage for a future production of NanoPiDuo to fully
expose such pins to use if needed, including the °°°line inputs°°°

As many programs use them, especially for radioamateurs use
the soundcard as a two channel line input

So many programs can work, embedded, likely without mods
and take avantage from small form factor of your card !

(And if possible also I2s audio support)