CC2640R2F: Change MAX_PDU_SIZE and then occur problem communication Bluetooth V5.0

Hello Vasu Khwanyuen,

Thank you for reaching out.

Configuring the stack to handle larger PDUs implies a larger RAM consumption. This may be the root cause of your issue. In order to check this, I would recommend leveraging the ROV and double check the heap status, as of the stack status for each task.
Please reference the debugging guide for more details about the ROV tool: https://software-dl.ti.com/simplelink/esd/simplelink_cc2640r2_sdk/5.30.00.03/exports/docs/ble5stack/ble_user_guide/html/ble-stack-5.x-guide/debugging-index.html#ti-rtos-object-viewer

I hope this will help,

Best regards,

Thank you Clement,

I try additional test. Set reduce MAX_PDU_SIZE

If try case below

MAX_PDU_SIZE 255 can transfer data 124 bytes

MAX_PDU_SIZE 200 can transfer data 132 bytes

MAX_PDU_SIZE 180 can transfer data 143 bytes

MAX_PDU_SIZE 160 can transfer data 159 bytes

Thank,

Vasu Khwanyuen

Hi,

Thank you for these additional elements.

Could you please check whether the behavior is caused by the available RAM being insufficient? This can be done using the ROV tool. Please reference the debugging guide for more details about the ROV tool: https://software-dl.ti.com/simplelink/esd/simplelink_cc2640r2_sdk/5.30.00.03/exports/docs/ble5stack/ble_user_guide/html/ble-stack-5.x-guide/debugging-index.html#ti-rtos-object-viewer

Best regards,

HI Clement,

If config Heap size and stack size, It help improve this issues or not?

Note: I try reduce code size.

result if set MAX_PDU_SIZE 255 can transfer data 152 bytes

Thank,

Vasu Khwanyuen

Hi,

As mentioned before, it is likely the issue is caused by a RAM shortage. I have suggested a way to confirm this.
The results you have shared do point in the same direction, but I cannot tell for sure.

Best regards,

This is information of my project from (file .map)

I see area of RAM from map file. Memory it not full and it remain size for use

Thank,

Vasu Khwanyuen

Hi Vasu Khwanyuen,

I am afraid the statically allocated memory does not tell much about memory consumption while the program is running.

Please follow the guidance shared in my previous messages and repeated here for convenience to assess the amount of memory used at runtime

Clément said:

This can be done using the ROV tool. Please reference the debugging guide for more details about the ROV tool: https://software-dl.ti.com/simplelink/esd/simplelink_cc2640r2_sdk/5.30.00.03/exports/docs/ble5stack/ble_user_guide/html/ble-stack-5.x-guide/debugging-index.html#ti-rtos-object-viewer

Best regards,

Thank you for recommand.

I try to check run-time stack

stack not overflow

Thank,

Vasu Khwanyuen

Hi,

Thank you for sharing.

On the screenshot, it looks like only one task (Idle Task) has been started. Make sure to let the code run for some time before looking at the values.

Also, please take a look at the heap.

Regards,

Sorry I reply to late,

Check heap this point or other point?

Thank,

Vasu Khwanyuen

Hi Vasu Khwanyuen,

The menu "HeapMem" is probably the one you need here.

Best regards,

Hi,

I can not see detail of HeapMem during run-time

Thank,

Vasu Khwanyuen

Hi,

Great to see the issue is solved! Well done!

Your observations make sense. As mentioned before, the issue is due to heap memory shortage. So the more heap memory you have, the less likely you are to reproduce the issue.

Here, when reducing the stack size of certain tasks, you save some RAM that can be allocated as heap. This is why the issue disappears.

The recommended way to configure the stack size, is to use the ROV (as done before). Then, using the "task" view, you can check the stack peak for each task. The stack peak should be considered after running the device in its expected working conditions.

I hope this will help,

Best regards,

Thank you Clement,

So, Should have stack size more than stack peak follow your recommend.

How much margin of stack size more than stack peak?

Thank,

Vasu Khwanyuen

Hi,

Vasu Khwanyuen said:

So, Should have stack size more than stack peak follow your recommend.

Correct!

Vasu Khwanyuen said:

How much margin of stack size more than stack peak?

Assuming you have identified the worst case scenario the margin to apply can be pretty small (a couple of bytes only).

Regards,

I suspect this point. I understand point check stack but if i try reduce size stack of task (SSS_TASK_STACK_SIZE) and then when check  stack in (ROV)  in stacksize it not reduce.

Thank,

Vasu Khwanyuen

Hi Vasu Khwanyuen,

The ROV shows the status of the idle task stack, not the status of the simple serial socket task.

Regards,

I can understand more now.