CC2564MODA: SPPM_WriteData sends less and less amount of data and fails

Hi Milan,

Are you trying to run a demonstration? I have a linked a pdf for a demonstration of SPP on the CC256x.

Did you configure your project in the same way as in the example?

Thank you,

-Ryan

3465.CC256x TI Bluetooth Stack SPPDemo App - Texas Instruments Wiki.pdf

Hi Ryan

I got inspiration from LinuxSPPM.c example. On the device, there is running Bluetopia Platform Manager.
The methods (like SPPM_WriteData) used in my implementation are declared in SPPMAPI.h.

Are you suggesting to use SPP_ methods instead of SPPM_ methods?

BR Milan

Hi Milan, 

The SPPM examples from BluetopiaPM are used when using the CC256x with a linux-based MPU. The SPP examples are part of the normal Bluetopia platform which pairs with an MCU. 

In your case, you are correct to be looking at the SPPM demonstrations while running Bluetopia Platform Manager.

Just for my own clarification, can you confirm that the method used to write data to the bluetooth socket was created by you and the SPPM_Data was created using the example in BluetopiaPM?

Best,

-Ryan 

Hi Ryan

Yes, I can confirm that. The difference from LinuxSPPM implementation is in write timeout - I used SPPM_WRITE_DATA_WRITE_TIMEOUT_IMMEDIATE, and empty buffer callback concept. So, if method SPPM_WriteData returns 0, I wait for callback that the buffer is empty. Then I write the rest of data etc. You can see that from the logs above. However, due to unknown reason, less and less data are written. It fails before all data are sent.

BR Milan

Hi Milan,

Have you been successful in running the LinuxSPPM.c example? In the example, it uses SPPM_WRITE_DATA_WRITE_TIMEOUT_INFINITE, which may point to an error with your timeout value.

Best, 

-Ryan

Hi Ryan

I know that LinuxSPPM uses _INFINITE. But this is not the approach I need. I need to have _IMMEDIATE with the empty buffer callback.

With best regards,
Milan

Hi Milan,

Are you able to run the demo successfully and see the correct amount of data being sent?

-Ryan

Hi Ryan

I have not tried to use demo to send such big data. I could implement _INFINITE in my application. Do you see any issue in usage of _IMMEDIATE and empty buffer callback concept?

BR Milan

Hi Milan, 

Can you please try to run the demonstration? If you are able to run it successfully, then I would recommend modifying the demonstration to use the _IMMEDIATE value in place of the _INFINITE value and test again. 

I'm just looking to see if this is the root cause of the issue, or if we need to be checking another area.

Best,

-Ryan

Hi Ryan,

Sure I will try that. I am travelling without the device. I will continue when I am back.

BR Milan

Hi Milan,

Thank you! Safe travels.

Best,

-Ryan

Hi Ryan

Thanks! I am back. I used _INFINITE instead of _IMMEDIATE. With this setting the application got stuck - no response from SPPM_WriteData.

BR Milan

Hi Milan, 

What does the receiving end of your BT configuration look like? Are you able to see successful transfer of the correct number of bytes on both the sending and receiving side?

Best,

-Ryan

Hi Ryan

Yes.

BR Milan

Hi Milan,

Just to confirm--you have tested both the IMMEDIATE and INFINITE values in the demonstration and have seen correct functionality with both?

Is there another portion of your application that you changed from the original demo where it could be interrupted?

Best,

-Ryan

Ryan,

IMMEDIATE fails as mentioned at the beginning of this thread and INFINITE stuck. Neither case works for me.

BR Milan

Hi Milan,

Which version of the BluetopiaPM Stack are you using? Additionally, what is the host that you are using with the CC2564MODA?

Can you please run the base demonstration provided in the BluetopiaPM stack without any modifications and send over Firmware and HCI logs to see what is occurring?

Best,

-Ryan

Building off of this, when you run the demo are you seeing a similar output to the one below?

On our side, we are able to see that the transmission thread has started, but then it gets hung on the transmission of data. I have not seen a case where this much data has been sent at once, so I will look into the limitations of it as well.

Hi Ryan

We are using AM335xBluetopiaLinuxProduction-4.0.3.0.1.0.
Let me share one thing that helps to send big data over Bluetooth using Bluetopia stack. I simply sliced the big data to small chunks each 1024 bytes big.
It means that I am calling SPPM_WriteData with IMMEDIATE and data of 1024 bytes until all data are sent over. It seems that stack is able to handle it.
Is there any limitation related to stack or hardware that one shall follow?

With best regards,
Milan

Hi Milan,

Thank you for that clarification--Can you please run the base demonstration provided in the BluetopiaPM stack without any modifications and send over Firmware and HCI logs to see what is occurring? I will look through these logs to see what may be happening

Best,

-Ryan