Simultaneous DSP and LE Audio transmission on nrf5340

RE: Simultaneous DSP and LE Audio transmission on nrf5340

Samruddhi Jadhav — Mon, 05 Oct 2026 11:48:43 GMT

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

RE: Simultaneous DSP and LE Audio transmission on nrf5340

npwalker — Fri, 02 Oct 2026 22:00:10 GMT

Thank you for your reply. To your point about output 1, the second nrf5340 will be connected to (and powered by) a phone via USB-C, not a PC. Would that work as well? I saw the reply to this ticket and assumed my use-case would also be satisfied.

For output 2, unfortunately if I get output directly from the codec, then output 2 will be skipping the processing step which is required for both outputs. According to the specification, nrf5340 I2S interface supports "simultaneous bidirectional (TX and RX) audio streaming." So if this nrf5340 is the master, then both the ADC and DAC could share its clock signals and connect to SDIN and SDOUT respectively? Or have I misunderstood? Thank you for your patience. I am trying to understand.

As a side note, I do not wish to use the built-in ADC since it does not meet my minimum audio quality requirement of 16-bit depth.

RE: Simultaneous DSP and LE Audio transmission on nrf5340

Turbo J — Fri, 02 Oct 2026 21:02:15 GMT

Output 1 does not work unless the second nrf5340 is connected to a PC host.The USB peripherial supports device mode only on this MCU.

Output 2 has the issue that the NRF5340 only supports one I2S peripherial, and its already used by the mic input. It could work if the mic codec also operates the output and has both input and output available on its I2S interface.