large data send central to peripheral nrf52832

[Autobot]

Hello everyone,

I need transfer large data 12KB array send central to peripheral using nrf52832. I try this examples in central (ble_app_uart_c) and peripheral (ble_app_uart). I add this few line in central

for(;;){

            uint16_t cnt=0;
           for(cnt=0;cnt<12000;cnt++)

            {
                uint8_t data=array_data[cnt];
            ble_nus_c_string_send(&m_ble_nus_c, &data, sizeof(data));
            
            }      
            
            idle_state_handle();
        }

peripheral doesn't receive any data from central. any example function or code is there to communicate central and peripheral transfer large data....????

[awneil]

You're not checking the return result from ble_nus_c_string_send()

How to properly post source code:

[Jørgen Holmefjord]

Like awneil said, you need to check the return code from call to ble_nus_c_string_send(). Most likely you fill up the notification buffer with the first data that is being received on peripheral side. Since you do not check return code, the rest of the data is lost.

uint8_t data=array_data[cnt];
ret_code_t err_code;
do
{
    err_code = ble_nus_c_string_send(&m_ble_nus_c, &data, sizeof(data));
} while (err_code == NRF_ERROR_BUSY || err_code == NRF_ERROR_RESOURCES);
APP_ERROR_CHECK(err_code)

A better solution is to wait for the actual events described under Return values in sd_ble_gattc_write().

[Autobot]

thanks for Jørgen Holmefjord,

I check this return code

do
{
    err_code = ble_nus_c_string_send(&m_ble_nus_c, &data, sizeof(data));
} while (err_code == NRF_ERROR_BUSY || err_code == NRF_ERROR_RESOURCES);
APP_ERROR_CHECK(err_code);

return this kind of error message show

 0> Logs dropped (45)
 0> <warning> ble_nus_c: Connection handle invalid.
 0> Logs dropped (45)
 0> <warning> ble_nus_c: Connection handle invalid.
 0> ndle invalid.
 0> ndle invalid.
 0> <error> app: Fatal error

Any other way to have possible send large data in NUS service...???

[Jørgen Holmefjord]

You should debug the application to see what function are returning error, and what the error code is. The log will output this if you define the DEBUG flag. You can find a video tutorial for debugging in Segger Embedded Studio on YouTube.

[Autobot]

I debug this application err_code shown.

 0> <warning> ble_nus_c: Connection handle invalid.

this kind of error show in central side how solved it...???

[Jørgen Holmefjord]

Did you lose the connection? Is the connection handle a valid one?

[Autobot]

how to make connection handle valid for very transmission in

 ble_nus_c_string_send(&m_ble_nus_c, &data, sizeof(data));

[Jørgen Holmefjord]

Connection handle is stored in m_ble_nus_c. You should make sure it is valid whenever you call ble_nus_c_string_send, or do not pass the error code to APP_ERROR_CHECK() if you do not care about data loss:

ret_code_t err_code = ble_nus_c_string_send(&m_ble_nus_c, &data, sizeof(data));
if(err_code != NRF_ERROR_INVALID_STATE && err_code != BLE_ERROR_INVALID_CONN_HANDLE)
{
    APP_ERROR_CHECK(err_code);
}

[Autobot]

Thanks for helping Jørgen Holmefjord,

Now i send 244byte in single transmission. i split 10000bytes into 244 bytes in every transmission but first transfer data receive peripheral(app_ble_uart) and balance data doesn't receive in peripheral side error code show

 0> <warning> ble_nus_c: Connection handle invalid.

 0> <warning> ble_nus_c: Connection handle invalid.

for(;;)
{
uint8_t Buff[244];
uint8_t cp_Lnt=0;
	for(uint16_t cnt=0;cnt<10000;cnt++)
			{
				Buff[cp_Lnt]=data[cnt];
				cp_Lnt++;
				if(cp_Lnt>=244)
				{
				err_code=ble_nus_c_string_send(&m_ble_nus_c,Buff, sizeof(Buff));//send_Data
				if(err_code != NRF_ERROR_INVALID_STATE && err_code != BLE_ERROR_INVALID_CONN_HANDLE)
					{
							APP_ERROR_CHECK(err_code);
					}
					cp_Lnt=0;
				}
			}
	}

in peripheral side connection interval set below

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS)
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS)

what are the parameters to change getting all data receive peripheral side without losing connection and data losses...???

[Jørgen Holmefjord]

You should figure out what is causing the disconnect. Can you provide a sniffer trace of the on-air traffic using the nRFSniffer v2?

[Autobot]

I don't have a Sniffer board please give any other way to find this problem solving method..???

I put delay of 2 second in every transmission all bytes receive success without any loss

    nrf_delay_ms(2000);

    err_code=ble_nus_c_string_send(&m_ble_nus_c,Buff, sizeof(Buff));

but i remove this delay continuously reset. i need without delay my code working function receive all data with in 1 second...???

[Jørgen Holmefjord]

Could be that the other device gets an error code, or that there are some unhandled events that cause the link to be broken. This would be much easier to debug with a sniffer trace. I would absolutely recommend getting another DK that you can use to sniff the connection, it is a valuable debugging tool when developing Bluetooth applications.