A2DP Multicasting or Broadcasting with Stellaris and Bluetopia

I'm looking into the possibility of using a Stellaris LM3S969B with the Stonestreet One Bluetopia stack for A2DP audio multicasting or broadcasting, most likely using a single source to send the same material to two sinks that render the material simultaneously and in a well synchronized manner.

StellarisWare includes sample code for implementing an A2DP audio sink (referred to as bt_a2dp_safertos), but no sample code for implementing and A2DP source.

1. Does the Bluetopia stack provided with the DK-LM3S9B96 Stellaris development kit provide the functionality necessary to implement an A2DP audio source? Are there licensing restrictions that prevent using the free stack to implement an audio source? Is there sample code available for this?

2. Is this version of the Bluetopia stack capable of supporting an A2DP multicasting or broadcasting source scenario? If so, any recommendations on how to implement this would be much appreciated.

3. If this is possible, will it be necessary for the source to perform SBC encoding multiple times, once for every sink? If this can be done without redundant encoding, how might it be approached?

4. Will the UART connection to the PAN1323 be capable of supporting the required data rate if the source material needs to be sent to it multiple times?

I'd be grateful for any assistance that could be provided.

19 Replies

  • Richard,

    I am checking with our partner SSO to provide you an accurate response to all your questions.

    Miguel

  • Hello,

    Here is some information about the questions asked. 

    1. Yes, the functionality necessary to implement A2DP audio source is provided. Please refer to the API document for the same. There are no licensing restrictions, the application can implement the source, unfortunately sample source is not available at this point.

    2. Yes, Bluetopia stack does not have any limitations for this scenario. 

    3. It sounds like you want to send same stream to multiple sinks. In that case, the application can encode it once and send it to multiple sinks. The exact implementation is application specific but encoding once for this use case should be enough.

    4. The UART is able to handle at least 4Mbps so it should be able to handle source material sent multiple times.

    The bit rate required, number of connections etc will all be factors but it is possible to send a stream to multiple sinks.

    Best Regards,

    Stonestreet One.  

  • In reply to Stonestreet One Support:

    Is it possible to Build A2DP source and Sink on a single module ... ie can I make a device which can receive from a source and retransmitt  the same to a A2DP Sink?

    thanx in advance ..

  • In reply to vishvesh deobhankar:

    Yes. You can use the API's provided by Bluetopia to create the A2DP source application on top of the Sink demo. Unfortunately, we do not have A2DP source code for the stellaris platform as of now.

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  • In reply to Zahid Haq:

    Hi.. Zahid


    1  can i use C256x Bluetooth/Dual-Mode Evaluation Module and MSP430F5438  A2DP or stereo audio transmission to headset or cell phone?

    2  how its possible?

    3 Is demo code available?

    4 which software i should use?

    Thanks

  • In reply to vipul prajapati:

    Hi Vipul,

    You can use MSP430F5438 + CC256xB(CC256xQFN) module to make it as audio sink.

    See http://processors.wiki.ti.com/index.php/CC256x_MSP430_Bluetopia_Basic_AssistedA2DPSinkDemo_APP

    Or you can use the EVM http://www.ti.com/tool/bt-mspaudsink

    See http://processors.wiki.ti.com/index.php/CC256x_Audio_Sink_Quick_Start_User_Guide

    For the demo code you can use the “A3DPDemo_SNK” sample app from Bluetopia 1.4 R1, which you can get from the Software section of the above link.

    For A2DP source you need to implement, as this demo is not available at this moment 

    Thanks for posting on TI E2E forum. We appreciate your feedback!
    Sundeep.

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  • In reply to Sundeep Javvaji:

    Thank you

     Sundeep

    i have checked Bluetooth and MSP430 Audio Sink Evaluation Module detail.

    i want  transfer audio signal from television to Mobile or Headset by A2DP.  mean i want to design transmitter. Bluetooth and MSP430 Audio Sink Evaluation Module is shown as reverse mean mobile to speaker.


     so is it useful to design Transmitter?

    Thank you

     

  • In reply to vipul prajapati:

    Hi Vipul,

    It is up to you to decide. But it is possible, please refer to the above posts by StoneStreetOne and Zahid.

    Thanks for posting on TI E2E forum. We appreciate your feedback!
    Sundeep.

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    Don't forget to check out our wiki page for lots of useful info:  Wireless Connectivity Platforms
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  • In reply to vipul prajapati:

    Hey  Vipul ,

    Actually what I understand is you want to make your module as Source which will establish a link to headphone/mobile phone ???

    If you design a source (transmitter) you have to decode the television signals to PCM and then transmitt the same using A2DP  I think this is the only way out of the problem .  

  • In reply to vishvesh deobhankar:

    Thanks  Vishvesh

    You got Right me. actually i want universal transmitter which can receive audio from 3.5mm audio jack and transmit for BT headset (stereo A2DP) like nokia etc or for cell phone. cell phone work as slave and transmitter as master.

    so  for audio which codec i should use and any ready development board and code  available for same?

    Thanks