I'm late to the party, but really like where this concept is heading to!
If it were me, I would implement this as RS232 serial comms, and then try to go about seeing if someone wanted to write a generic audio-to-serial device driver that emulated a serial port at the kernel level. Then the separation of duties in the code is appropriate, and the audio overhead is totally optional.
Yes, I totally agree, a generic, modular solution would be sweet.
Both devices use a (virtual or physical) RS232 port, where users can decide what they put in between the two systems.
I would then not use an audio layer on top of that, but an optical:
- a green LED for sending data from online to offline, shining onto a phototransistor connected to the offline system
- a red LED for sending data from offline to online, shining onto a phototransistor connected to the online system
They flicker happily away, should be pretty fast too, and I immediately see when and how long they transmit data, and in what direction too!
Other users might prefer the audio link. Or a plain direct RS232 cable.
What do you guys think?
Ente