Set nRF5340 Audio DK as I2S slave over external bus

[max.proskauer]

Hello! I am attempting to use my nRF5340 Audio DK as a gateway to broadcast audio from an external I2S source.

I have added the `CONFIG_AUDIO_SOURCE_I2S=y` line to my project .conf file as described in the README for the nrf5340_audio project.

I also have followed the instructions in this DevZone post to configure the board to use the external I2S connections on the P10 header.

The issue that I am encountering now is that the nRF board is still acting as the I2S master. The other device I want to connect I am not in control of and is configured as an I2S master. I need the nRF board to act as I2S slave and transmit the audio the other device is sending it over the Bluetooth link (in my case as a BIS broadcast). How can I configure the nRF as I2S slave?

[max.proskauer]

OK I do have a non-audio DK on hand. Should I use the same nrf5340_audio application? Does it require any config changes to switch boards? Thanks!!

[Amanda Hsieh]

Hi, 

I would also try with:

NRF_I2S_FORMAT_I2S instead of ALIGNED. 16 bits in 32-bit frame is also very uncommon. That means half the data is "wasted" and I find it hard to believe that the other device has this configuration.

-Amanda H.

[max.proskauer]

That's what it uses. I've verified this with an oscilloscope.

From the vendor's datasheet:

[max.proskauer]

How do I build targeting the non-audio DK? I tried making a new build configuration using the nrf5340dk_nrf5340_cpuapp board target but it had a ton of errors. Thanks!

[Amanda Hsieh]

Hi, 

It cannot use the nrf5340dk_nrf5340_cpuapp board target for the nrf5340_audio application since you would miss all the audio DK hardware peripherals. You can create an I2S project to run on nRF5340DK. However, I have asked the internal and unfortunately, we don't have a related sample as your requirement currently. Sorry for the inconvenience. 

-Amanda H.