Duplex Audio Intercom implementation using NRF5340

[hundal]

Can a long-range, Mesh, duplex, Audio Intercom be implemented  using NRF5340-Audio-DK and NRF21540-DB Development kits? Is there any example of Duplex Audio Intercom availble using NRF5340?

[Maria Gilje]

Hello,

I will give you some initial thoughts and come back to you once I have researched this some more.

Currently our solution for LE Audio is a precompiled binary which is the Bluetooth LE Controller dedicated for the nRF5340 Audio application. Multiprotocol is not possible with this controller.
The SoftDevice controller does not support ISO, so an alternative would be the Zephyr Bluetooth LE controller.
To my knowledge there is no examples for Bluetooth Mesh and Bluetooth LE coexistence in nRF Connect SDK.

I'll be back with more information soon. Thank you for your patience.

Best regards,

Maria

[hundal]

Dear Maria,

Thanks for your initial feedback! Pls allow me to elaborate my query a bit more:

We want to build a mesh-wireless-intercom *** mobile-bluetooth-headset that connects to another wireless intercom upto say about 1 km range directly and should be able to connect to other wireless intercom via mesh as well. The wireless intercom will also have connectivity with mobile and mobile app via bluetooth for settings change or play music or make calls like a standard bluetooth headset.

I have seen applications using following hardware: NRF52840 + NRF21540 for mesh audio communication and another standard bluetooth controller for communication with mobile phone. An ARM microcontroller controls the functions and settings and a stero codec IC DA7212 is used for mic/speakers interace. We have exact same requirement as this application but want to use NRF5340 instead of NRF52840.

Can you help us with a hardware block-diagram/key-components of the design required for making above application? Is NRF5340+NRF21540 correct choice in your opinion? Any advice to give us a headstart in design of the mesh-wireless-intercom *** mobile-bluetooth-headset is welcome. 

[Maria Gilje]

Hello,

hundal said:

We want to build a mesh-wireless-intercom *** mobile-bluetooth-headset that connects to another wireless intercom upto say about 1 km range directly and should be able to connect to other wireless intercom via mesh as well. The wireless intercom will also have connectivity with mobile and mobile app via bluetooth for settings change or play music or make calls like a standard bluetooth headset.

From this description I interpret that the product will have two main modes: headset and intercom.

Q1: Will the two modes be active at the same time or does the device switch in between them?

The headset part should be pretty straightforward when using the nRF5340 Audio application as a starting point. The application has support for both a unidirectional(default setting) and a bidirectional headset. 
The intercom part will be more involved, as there are no existing samples in nRF Connect SDK which demonstrates such a functionality.

hundal said:

I have seen applications using following hardware: NRF52840 + NRF21540 for mesh audio communication

Q2: Could you share more details on what this application is?

As mentioned above, we don't have and existing sample for audio intercom. It is likely that the existing application has a proprietary solution for mesh audio.

hundal said:

Is NRF5340+NRF21540 correct choice in your opinion?

For Bluetooth LE Audio, the nRF5340 is the recommended SoC. For the other parts of your system I need more details to be able to comment.

Best regards,
Maria

[Maria Gilje]

Hello,

Maria Gilje said:

It is likely that the existing application has a proprietary solution for mesh audio.

It has been confirmed that the existing project contains proprietary features which we can not provide.

Your RSM has contacted you with some more context and reasoning via e-mail. Please take that into account.

We are happy to help you with Nordic related challenges you may meet during development.

Best regards,

Maria