A concept for this board and future Radxa boards …
Is it possible to add a second header below the 40 pin header ? This second header could be specifically for audio I2S lines. The second header could be 16 to 20 pins large.
You could map all of the I2S1 m1 or m0 lines to that header.
You could map all of the I2S2 m1 or m0 lines to that header.
You could map an I2C bus to that header.
For audio related applications this second header would be extremely useful.
For the I2S1 lines, it would need
For the I2S2 lines, it would need
Then 2 lines for an i2c bus.
If possible 1.8v would be good, however voltage domain switchable to 3.3v would be even better.
You could even go crazy and add the I2S3 bus to that header too !