BL Audio multicast

Question

Hello, 
 we are starting application and make sure we chose the right technical solution. 
 We have nRF5340 Audio DK boards to develop our FW. 
 Scenario: 
 Instructor talks to one/multiple/all students during outdoor sports. Typically about 10 students in one group. 
 We want singe audio source to send a voice to the multiple listening devices however the transmitter needs to be able to choose who will hear the audio. 
 Priority is range (hundreds of meters). Voice only audio quality is enough. 
 
 Possible solution according to our understanding: 
 We would need to pair the source device with all the listening devices so no one else can listen to the audio. 
 We would use BL audio broadcast to stream the audio. 
 There would be BLE connections with every listener, so the source device could notify every single listener to connect/disconnect the audio. 
 
 Is our solution correct or is there a better way? 
 
 Thank you 
 Jeronym

Karl Ylvisaker · Accepted Answer

Hello Jeronym, 
 JeraDrson said: The privacy is not an issue in this application. Therefore we would try the solution with broadcasting the mask. 
 Could you please give me some advice regarding this solution? Could we encode the mask to some stream information? Or the second audio channel? Or create some non audio broadcast channel? 
 Great, that sounds like a good idea! Please do not hesitate to ask or open a new ticket if you should encounter any other issues or questions when you give this a try! You can set up regular advertising alongside the broadcast to broadcast the mask - this way you do not have to create an implementation that continuously scans the received audio to extract the mask. For simplicity in the beginning you can basically set up an advertisement that contains a number, and have each device know their own identity number in order to know if they should listen in to the secondary broadcast or not. In the next step you can then have all the peripheral devices advertise their own ID's on a buttonpress (such as during setup for the practice) so that the central can know 'who is available'. And for the final version perhaps you would like to use NFC or something similar to 'scan' into the training session, so that the head coach easily can know who is in the session and what their peripheral ID they are using. There are many ways you can achieve this, and you might already have a plan for something other than my suggestion above, in which can you can disregard it - this was just the first I envisioned based on the understanding I have of your targeted use-case. Best regards, Karl

JeraDrson · Answer

I found out the is bt_le_scan_stop function call in pa_synced_cb, after commenting this out it seems my data is being received correctly.

BL Audio multicast

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