How to get I2S audio flowing out of the 40 Pin header of Raspberry Pi?

I am using Raspberry Pi 3B as a development tool for audio algorithms. SO far, I have successfully followed the steps below -

1. Flashing the MATLAB version of the OS on the micro-SD card

2. Connecting via an Ethernet jack 

3. Passing audio through the "raspberrypi_audioequalizer" example to the Raspberry Pi and

4. Sending the output through the 3.5 mm jack.

The issue is that I have to use an external board which accepts I2S instead of analog. I do not see any option to enable this (though I have looked in the raspi-config UI, Advanced, Audio, and tried "0"{default}, "1"{3.5 mm jack}, and "2"{HDMI} ).

How can I get I2S audio flowing out of the 40 Pin header? Perhaps the Linux Kernel / Version I burned onto the micro-SD card simply doesn't have the I2S port enabled/integrated.

Answer 1

[MathWorks Support Team]

You need to create your own I2S driver block if you want to tap clock and data from the GPIO (general purpose input/output) pins. Our audio capture/playback blocks work only with ALSA compatible devices. The device should be plugged into Raspberry Pi and should be detected as a playback device (use ‘aplay -l’ to get the list). You might want to try using "SainSmart HIFI", which is an I2S based DAC that can be plugged onto Raspberry Pi (just like Sense HAT).