• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 51 subscribers
  • Views 371 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CC2564CSTBTBLESW: L2CAP message transmission throughput of Bluetopia V4.2.1.1 stack

Qiang Xie
Prodigy 20 points
Part Number: CC2564CSTBTBLESW
Other Parts Discussed in Thread: CC2564C

Hi,

We are having a show stopping issue regarding L2CAP message transmission throughput. Our application uses Bluetooth SDK for STM32F4xx + CC2564x: CC2564CSTBTBLESW (Bluetopia V4.2.1.1 stack)

The application requires transferring large amounts of data (~10MBytes) through the L2CAP channel as fast as possible. We use the Bluetopia function L2CA_Enhanced_Dynamic_Channel_Data_Write() to send data. However, after we call L2CA_Enhanced_Dynamic_Channel_Data_Write() to send 1110 bytes of data. We have to wait for about 150ms before we can call this function again to send another 1110 bytes. Basically this is an effective baud rate of only 59.2 Kbps which is far slower than the configured 921.6 Kbps HCI baud rate. If we send the next message with a delay less than 150ms, we will get an error message of BTPS_ERROR_INSUFFICIENT_RESOURCES (-66).

How can we improve the L2CAP message throughput to be as close as possible to 921.6 Kbps HCI baud rate?

Thanks,

Qiang

  • 0
    TI__Mastermind 40965 points

    Hi Qiang,

    Looking through the Bluetopia codebase, there are quite a few reasons why BTPS_ERROR_INSUFFICIENT_RESOURCES can be thrown, usually due to a lack of memory or buffer space. Does changing the BTPS_MEMORY_BUFFER_SIZE heap allocation in btpskrnl.c make any difference in the behavior observed?

    Also, can you please provide the debug logs from the CC2564C as you run your throughput testing? Instructions on how to get the BT debug logs can be found here: https://www.ti.com/lit/swau058

    Regards,

    Michael

  • 0 in reply to Michael Reymond
    Prodigy 20 points

    Hi Michael,

    Thank you very much for your quick reply.

    Unfortunately doubling the size of BTPS_MEMORY_BUFFER_SIZE didn't make any difference. I haven't got some time to get the debug logs yet.

    However I have a related fundamental question, what is the maximum real world throughput for an application using LE (not BR/EDR) with CC2564B controller under Bluetopia V4.2.1.1 stack?

    Thanks again,

    Qiang

  • 0 in reply to Qiang Xie
    TI__Mastermind 40965 points

    Hi Qiang,

    The maximum real world throughput on an LE connection on the CC2564B is not characterized. The existing test data I can find is for BT classic applications. I'll keep looking and see if we have LE throughput test data but I don't think it exists unfortunately.

    Let me know when you get those debug logs.

    Regards,

    Michael