I just bought the Rock PI S v1.2 and wanted to attach a simple I2S audio amplifier (Adafruit I2S 3 W CLASS D AMPLIFIER Breakout MAX98357A)
I installed the Ubuntu Bionic image from the downloads page.
aplay -L is showing the rockchip acodec device (default:CARD=rockchiprk3308a) and I can start speaker-test to play something on the device. However, there is no sound. All of the SDO and LRCK pins as well as whe MCLK pins stay quiet.
After some digging in the device tree it looks like the I2S0 device is disabled and I found the DMIC overlay. The DMIC overlay seems to work and activates the MCLK but still no sound output.
My knowledge of device trees is extremely limited and I have not been able to hack something together that would expose I2S0.
I cannot believe that noone has tried to play sound through the digital interface?
I searched through all the forums and google, is there an existing overlay to activate this?
I found the Hifiberry overlay for the RockPi4 and decompiled it but it looks sufficiently different that I am pretty sure it wouldn’t work just like this.