Simultaneous DSP and LE Audio transmission on nrf5340

[npwalker]

My desired work flow is the following.

Input: Two electret microphones -> Audio ADC -> I2S Stereo -> nrf5340

Processing: Buffers (10-50 bytes) channel 2 to create delay, subtracts delayed channel 2 from channel 1, and outputs single-channel signal. This is a simple differential beamformer and needs to run at the ADC sampling rate of 44.1 kHz.

Output (two user options):

1. nrf5340 -> LE Audio -> a second nrf5340 -> USB audio class -> USB-C
2. nrf5340 -> I2S mono -> Audio DAC -> 3.5 mm audio jack

Can the nrf5340 achieve this workflow without additional MPU or ICs (except the ADC and DAC already mentioned)? Specifically, can I implement this signal processing algorithm and run it simultaneously to LE Audio transmission? If so, can you recommend resources for utilizing the dual-core chip to achieve this? 

Thank you in advance!

[Samruddhi Jadhav]

Hello,

I have discussed this internally with the team and have some feedback here from them. From your description here, it doesn't sound too demanding CPU usage wise so we think you could manage without a DSP hardware codec or anything like that. So you should use the nRF5340. However, please note that, once you decide to implement an audio feature, you end up wanting to do a lot of other things too and these functions can be quite CPU-demanding. The Cirrus Logic chip on our audio dk is extremely powerful and it's a good starting point. We do not have any specific recommendations but I would suggest you to contact the regional sales manager of your area for further information about this. 

To build further on the first reply in this case, "output 1" problem is valid that it needs a USB host but phones can operate as that. When it comes to "output 2", we think it should work fine as long as the same sample rate is used just like with a walkie-talkie. 

Please let us know if you have any further questions. 

Best Regards,

Samruddhi