uhmmmmm.....!
Passing audio samples via RS232 is a *BIG* timing problem.
I'm working on something similar using a PIC, and for a I/Q sampling
(5 Khz sampling rate, 2 channels @ 10 bit per sample) it's mandatory a
230.4 kbps over the serial, otherwise it's impossible to send data
before a new sample is available.
This, en passant, is the highest *safe* speed over a bulk serial
installed into our PC; at this speed we have to send 4 byte (plus
start/stop bits):
1 byte as SYNC (otherwise we can go to swap/mix I/Q data)
2 bytes for lower bit data
1 byte for the most significant bit of data assembled together in one
byte.
At 48 khz sampling we need more than 2 Mbps over the serial.
Pay attention that RS232 line driver as MAX232 reaches there the
limit, so it's necessary other hardware.
Making the same via USB would be the right way, but ... isn't so
simple as RS232.
... so working in progress!
de i3vfj, Vittorio
