CC2340R5: UART overrun event has occurring

Hi Vignesh,

Thank you for reaching out.

Overrun error occurs when the CPU has not enough time to read the content of the UART buffer before the next chunk of data arrives.
I would suggest to try increasing the size of the RX ring buffer to see if it helps. I recommend the RX ring buffer to be at least larger than the UART messages expected to be received. The screenshot below shows how to do this:

Additionally, I recommend referring to the UART2 example synopsis: https://software-dl.ti.com/simplelink/esd/simplelink_lowpower_f3_sdk/7.40.00.64/exports/docs/drivers/doxygen/html/_u_a_r_t2_8h.html#ti_drivers_UART2_Synopsis
If not already done, try to call UART2_rxEnable prior to UART2_read().

With regards to the HAL_ASSERT_CAUSE_ICALL_TIMEOUT, I think it is caused by the execution of UART2_flushRx() disabling the interrupts longer than accepted by the BLEStack.

I hope this will help,

Best regards,

Hi clement,

Clément said:

I would suggest to try increasing the size of the RX ring buffer to see if it helps. I recommend the RX ring buffer to be at least larger than the UART messages expected to be received.

I have tried increasing the size of the RX ring buffer (above 32,64,300,1024) larger than the UART messages(20 bytes) and calling  UART2_rxEnable in UART _Init() function still when sending 20 bytes of data in a interval of 100ms UART overrun is occurring.

Thanks,

Vignesh.

Hi clement,

        The value of UART_MAX_READ_SIZE has 300.

 I have tried calling the function UART2_readCancel within the UARTCallback function uart overrun issue has not observed till now.

But when sending 20 bytes of data in a interval of 100ms UART overrun is occurring while going for an pairing with mobile.

Thanks,

Vignesh.

Hi Vignesh,

Great to see some progress.

Pairing operations require complex computation to generate encryption keys. As mentioned before, this leave the CPU with very little processing power left and could explain the issue observed.

Regards,

Hi clement,

         An interval of 100ms continuously pushing an data (Approx. 20 bytes) via UART to the peripheral. Now I have connected my mobile with peripheral device in link layer when trying to go for  pairing  I can pair successfully with the peripheral device(Just works). But UART overrun is occurring. 

We didn't faced these issues with CC2640R2F but in CC2340R5.could you please give any solution to prevent from occurring UART overrun while pairing.

Thanks,

Vignesh.

Hi Vignesh,

Could you please guide us to reproduce the same on the basic_ble example (i.e. without the ANCS code)?

In your case, are you running the UART operations in the same thread as the ANCS?

Regards,

Hi clement, 

     With basic ble example can able to reproduce with adding uart where the code provided in first and sending data Continuously  in uart now going for an pairing uart over run occurs. 

In the case of basic ble peripheral with ANCS, peripheral Rx is not working when uart overrun occurs. 

Yes, UART operations where running in same thread as the ANCS.

Can you just guide me to implement UART in different thread. 

Thanks, 

Vignesh. 

Hi clement,

       We have tried implementing UART in a different thread and didn't help to prevent from UART overrun event.

After we started analyzing the UART initialize and enabling the read callback there we found that BLEAppUtil_invokeFunction causing the UART overrun event.

Can you please try to recreate an issue by adding BLEAppUtil_invokeFunction in read callback and send data with the delay of 100ms on UART then parallelly try to pair, then UART overrun will occur.

Thanks,

Vignesh.

Hi Vignesh,

The data sent to the function with BLEAppUtil_invokeFunction need to be allocated with BLEAppUtil_malloc, could you try again with the following UARTCallback ?

#include <ti/bleapp/ble_app_util/inc/bleapputil_internal.h>
void UARTCallback(UART2_Handle handle, void *buffer, size_t count, void *userArg, int_fast16_t status)
{
    uartPacketSize = count;
    void *data = BLEAppUtil_malloc(count);
    memcpy(data, buffer, count);
    BLEAppUtil_invokeFunction(HandlingFunction, data);
}

Let me know if this fix the UART overrun.

Regards

Tanguy

Hi,

    I have tried by allocating BLEAppUtil_malloc in the UARTCallback function but still Overrun occurring.

Thanks,

Vignesh.

Hi Tanguy,

    I defined UART_MAX_READ_SIZE as 300. So I increased the size of the RX ring buffer 1800(300x6) and the UART overrun error has not occurred.

But RAM consumption has increased to 98% where using Multirole Profile with  ANCS and need to implement AMS also. Can you please suggest any other solution to prevent UART overrun error.

Thanks,

Vignesh.  

Hi Vignesh

I am glad to hear that increasing the size of the buffer solve the overrun error. Concerning the memory usage, you can try with a smaller buffer (x4, x5) maybe it is enough to avoid the overrun. The others way to avoid the problem would be to reduce the number of bytes sent or to increase the interval between 2 transmissions.

Concerning the memory usage, could you tell me what was the total memory consumption before increasing the size of the buffer?

To reduce the ram usage, you can check the max heap usage in the ROV and reduce the heap accordingly.

Regards,

Tanguy