CC2340R5: Delay in UART data receiving with Data stream

Gurpal Singh

Part Number: CC2340R5

Tool/software:

While working with CC2340R5, i have encountered a problem with uart receiving.
The original problem is in my custom project and in simple terms, My project is echoing data from UART to BLE and vice versa.

To ease the support, i have reproduced the problem in the example Data stream with minor addition of code.

Simplink SDk version used: 8.20.0.119, 8.40.2.01

i have done the following things to reproduce the issue:

I have added uart initialization in Data Stream example with default params.

UART2_Params p;

UART2_Params_init(&p);

myuarthandle=UART2_open(CONFIG_UART2_0, &p);

I am sending a byte stream from ble app nrfConnect to my cc2340r5 device and writing all data to UART using

UART2_write(myuarthandle, pValue, len,NULL);

i have also connected UART RX with UART TX to echo my data back.

i have added the following code to receive uart data and write back to BLE connection.

static void* uart_recv_task(void* vData)

{

ICall_EntityID entity;

ICall_SyncHandle msgSyncHdl;

ICall_registerApp(&entity, &msgSyncHdl);

uint8_t b[100]={0};

int a=0;

while (1) {

UART2_readTimeout(myuarthandle, b, 1, &a,1);

if(a>0)

{

DSP_sendData( (uint8 *)b, a );

}

vTaskDelay(1);

}

Now the problem is that i am receiving echo data in batches from ble. The issue is dependant on data length. Longer the length more batches are there.
i am attaching a screenshot of received data.

Since i have not added any such delays, the behavior is weird.
Also there is a pattern in the problem batch delays are almost multiple of 40.

I have also tested with ble disabled and by measuring tick difference between last sent on uart and last received on uart.
The tick difference is multiple of 10 in this case.

I have also verified that the uart_recv_task is being executed in every 2 ms.

I would appreciate any help.
Thanks

10 months ago

0 David 10 months ago

TI__Genius 16405 points

Hello Gurpal,

Thanks for reaching out.

Could you please increase the size of the UART read function? I believe you are reading only 1 byte each time.

Let me know how it goes.

BR,

David.

0 Gurpal Singh 10 months ago in reply to David

Prodigy 10 points

Thank you for your response.

To clarify, in the original scenario, I am using DMA mode and reading all available data from the ring buffer. However, I am encountering a similar issue where the data appears to be delayed.

To assist with troubleshooting, I have recreated this problem in an example project for easier reproduction.

Additionally, my application requires the ability to either read data byte-by-byte or to read all available data at once, depending on the situation.

0 David 9 months ago in reply to Gurpal Singh

TI__Genius 16405 points

Hello Gurpal,

Could you please share the latest UART section of that code? UART2_readTimeout(myuarthandle, b, 1, &a,1); are you not setting the size to 1 byte?

BR,

David.

0 Gurpal Singh 9 months ago in reply to David

Prodigy 10 points

Thanks for the reply
I have tested with increased length, and it works fine.

I wonder why it's not working with size 1.

0 David 9 months ago in reply to Gurpal Singh

TI__Genius 16405 points

Hello Gurpal,

By setting size to 1 you are only reading 1 byte at a time until emptying the buffer.

BR,

David.

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CC2340R5: Delay in UART data receiving with Data stream