NRF 5340 DK LE audio capability

[mohamed_13]

I am using an nrf5340 DK instead of the audio DK. Is BT LE possible with this DK. Is there any difference beween NRF5340 DK and audio DK in terms of microntroller. 

[mohamed_13]

Hi,

Thanks for the input. 

The project I'm working on involves a Bluetooth hearing aid. The device should output stereo audio from either of the sources

• stereo microphones
• bluetooth
• aux

Im thinking of using a DSP audio codec plus the NRF4340.

Would you kindly tell me what all are the necessary hardware changes I need to make the nRF5340 Audio applications to work on the nRF5340 DK?.

[Maria Gilje]

Thank you for describing your project, this additional information is very valuable.

mohamed_13 said:

The project I'm working on involves a Bluetooth hearing aid. The device should output stereo audio from either of the sources

• stereo microphones
• bluetooth
• aux

mohamed_13 said:

Would you kindly tell me what all are the necessary hardware changes I need to make the nRF5340 Audio applications to work on the nRF5340 DK?.

We don't have any official guidelines for nRF5340 Audio applications on nRF5340 DK so the infomation below may not be complete.

The features which the nRF5340 Audio DK has and that nRF5340 DK doesn't have are these:

Mono hardware codec

Since you are working on a hearing aid which has mostly headset functionality, you need to add a hardware audio codec, which I can see that you have planned to use a DSP. You will also need to add a hardware codec to convert the audio before/after processing. Also, since you want stereo output you need to use a stereo hardware audio codec, which is not on the nRF5340 Audio DK, but we have some guidelines for how to connect an external codec to the nRF5340 Audio DK.

I appreciate if you can clarify this for my understanding: You write that the hearing aid should output stereo audio, does that mean that both the left and the right device will output the same audio, or should the left device output the left audio stream and similar for the right?

AUX input and output ports

For testing the audio output you will also need to connect speakers to the DK. The nRF5340 Audio applications uses the output jack for this purpose, that is, a speaker or headset it connected to the jack. The audio is sent from the nRF5340 soc to the onboard hardware codec which forwards the analog audio to the output AUX jack It is ultimately up to you how you want to solve this for your development, but choosing a similar solution to the nRF5340 Audio DK and applications could make it easier for us to support you.

PDM microphone

The PDM microphone on the nRF5340 Audio DK is routed through the hardware codec and is a convenient way to use live sounds as the input audio. In the nRF5340 Audio applications thisis demonstrated in the walkie-talkie demo configuration.

RGB LEDs

The RGB LEDs are not necessary for the functionality of LE Audio on the nRF5340, but is a helpful visual aid to tell device types apart and to quickly tell the status.

If the needed additions seems too much, I do recommend the nRF5340 Audio DK for development of your LE Audio hearing aid device.

mohamed_13 said:

Also, I want to know what type of Bluetooth profile is available in the examples.

Currently we don't have any qualified LE Audio profiles in nRF Connect SDK. We have samples which demonstrates the functionality as well as QDIDs for the Bluetooth Host and SoftDevice Controller subsystems. See the Bluetooth samples available here and look for the LE Audio profiles in the list, for example HAP.

Best regards,

Maria