Auxiliary serial input

[tag]

I see the following in the codec datasheet:

"An auxiliary serial input is available for an additional two
channels of PCM data. "

I also saw the following comment about the OctoPi interface:

"You should just be able to pretend that it is an interleaved I2S bus, 8 channels both ways."

Does this mean that the auxiliary serial input can but used to achieve an 8x8 interface? Is that supported in the driver, or could it be?

[mhelin]

The Linux driver supports it I guess (or can be made easily) but the Octo card and it's FPGA code would need an update. But yes, Octo could be made a real 8x8 soundcard that way. Personally I wouldn't put the aux ADC on the card but instead just add an S/PDIF input followed by a sample rate converter so you could use some high-quality ADC for covering like the overheads on multi track drum set recording session.

However, even eight tracks is not much. On Raspberry Pi there is another way of getting masses of data into CPU, much more than the I2S/PCM GPIO port is capable. Something like 24x24 channels divided for an example to 3 full-duplex ADAT interfaces would be perfectly possible.

Also the USB interface is an viable solution. Biggest problem when using RPi for tracking audio is the lack of a proper HDD interface (IDE, SATA or M.2, or USB 3.x at least).