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Original question:

CC2640R2F: Audio BLE Application

CC2640R2F: Voice Over Bluetooth at 48/44.1 kHz and 16bit stereo

Michael Liesenberg85
Mastermind 7560 points

Part Number: CC2640R2F
Other Parts Discussed in Thread: CC3200

Hi,

is it possible to send 16 bit audio from I2S with stereo line in at sampling rates 48kHz or 44.1kHz over BLE?

Sending right channel and left channel ?

Can an iPhone handle this throughput? 

  • 0
    TI__Guru 57865 points

    Hi Michael,

    Assigning an expert to comment.

  • 0
    TI__Guru** 101490 points

    Hi,

    Obviously, you will not be able to transmit this much data (2*16*48kHz = 1536 kbps) without performing audio-compression.

    Reminder: the throughput of a BLE link using the 1M PHY is *not* 1Mbps. The throughput of CC2640R2 using PHY 1M is around 780 kpbs, using PHY 2M it is around 1350 kpbs. Regarding the iphone, the throughput depends on the iphone's version (for iphone 7, throughput is around 230 kbps using PHY 1M and around 450 kbps using PHY 2M).

    Regarding the CC2640R2F's I2S module, 16 bit stereo 48/44.1 kHz can definitely be handled.

    In summary, considering you compress enough the audio-data, you should be able to transmit the data as expected.

    I hope this will help,

    Best regards,

  • 0 in reply to Clément
    Mastermind 7560 points

    Hi Clément,

    thank you very much for your answer. By compressing the audio, the quality will decrease right?

    On classic Bluetooth  A2DP profile does the job but iPhone only works as source and not as sink.

    I am looking for alternatives right now, maybe CC3200 Wifi module can tramsit such amount of audio data to the iphone right?

  • 0 in reply to Michael Liesenberg85
    TI__Guru** 101490 points

    Hi,

    Well, some "lossless" compression algorithms / codecs exist. Depending on the application (i.e. what you are using the audio data for) maybe you can accept to lower a bit the quality? 

    Regarding CC3200 Wifi module, yes the throughput of Wifi is way bigger than the throughput of BLE. It does not mean that transmitting audio over Wifi without compression is a good idea. Once again, I don't know what are the constraints of your project so it is difficult to give you a better answer.

    Regards,

  • 0 in reply to Clément
    Mastermind 7560 points

    Hi Clément,

    I can't lower the quality because the audio data will be processed afterwards and mathematical function like FFT are used.

    I need at least 16bit and 44.1 kHz for 2 channels.

    I want to transmit wireless audio in high definition to an iPhone. Is Wifi the only possibility then?

  • 0 in reply to Michael Liesenberg85
    TI__Guru** 101490 points

    Hi,

    No Wifi, is not the only possibility to transmit wireless audio in high definition. As I mentioned you can compress the data (once again compression does not always means lower quality) to meet the limits of BLE's throughput.

    Regarding Wifi, yes it's also a way to transmit high definition audio data.

    Now, it's your job to select the most appropriate technology for your project. Throughput is a criteria to chose a technology but not the only one (what about power consumption, price, development team's capabilities, legislation, existing platform...).

    Best regards,

  • 0 in reply to Clément
    Mastermind 7560 points

    Hi Clément,

    ah ok sorry. So there is a way to send high definition audio sound with BLE with compression.

    My preference is BLE to connect to iPhone because i dont need to be part of MFI and yes i need it to be low power as possible.

    I am already using CC2640R2 in my products and i am very familiar to it.

    Is there a good example from TI that sends stereo audio to iphone? 

    How would i modify the  Voice over bluetooth example so that i can send stereo audio with compression?

    On the iphone side i will have to read its characteristics and decompress the audio file and separate right channel with left channel right?

    Kind regards,

    Michael

  • 0 in reply to Michael Liesenberg85
    TI__Guru** 101490 points

    Hi Michael,

    We plan to release latter this year (October) a new Audio SDK that will provide the examples you are asking for.

    To answer your question regarding audio decompression and channels separation on the iphone's side: yes you're right you will need to handle this.

    Regards,