I2S interface Ubuntu Core 22 [Rpi4 r1.3]

Hello everyone,

I am trying to turn on I2S interface via Ubuntu Core config.txt file like these lines:

dtparam=i2s=on dtoverlay=hifiberry-dac dtoverlay=i2s-gpio28-31 And commented line dtparam=audio=on. All this changes inside run/mnt/ubuntu-seed/config.txt.

What exactly do I do wrong?

I want to see /dev/i2s file for processing it in my own snap app.

Thanks for any thoughts!

I have discovered that the best way - connect it to ALSA, but if hifiberry-dac works well - I see active sound card, at the same time adau1977-adc doesn’t work - no one active sound card. While I cannot undersdand this difference between ADC and DAC for rpi4 (maybe for DAC rpi4 is generator of clocks, but for ADC is not)

Now I found out that I cannot add my .dtbo file to config.txt. Who can tell me how can I load my own overlay dtbo file to ubuntu core?