As my title says, I'd like to send audio from an rpi3b+ to another one. Preferably a zero one via a GPIO connection.
My target is to have a dedicated device to only manage an USB DAC. Ideally an Rpi Zero, because I want the smallest system footprint. (Compiled from minimal scratch, a kernel RT with minimal selected modules etc...)
I've tried to find documentation for
- Rpi3 -> PCM -> Rpi Zero (Analog :( )
- Rpi3 -> i2s -> Rpi Zero
- Rpi3 -> SPI -> Rpi Zero
- Rpi3 -> USB gadget -> Rpi Zero (Zero have only one port, and RPi can't manage master and slaves gadgets on the same board because only one controller)
- Rpi3 -> Ethernet-> Rpi Zero (Heavy system footprint to manage drivers, connections and so on)
And to select a way to transfer audio stream
- Raw PCM (Heavy workload for 24/96 target)
- Compressed stream (Larger footprint for the Rpi zero)
I’m looking for direct memory access too, but I can’t find a way to go any further :( Nevertheless, I2s DAC exists, but I can't find a way to connect two Rpis through this.
So I'm looking for recommendations!