my bluetooth gets disconnected while sending continous stream of data

RE: my bluetooth gets disconnected while sending continous stream of data

MANGO — Tue, 22 Mar 2016 00:40:00 GMT

Hmm, I think you just have to change the packet at ble_nus_string_send at my_nus_iter function.

Use a global variable or change the function input to get the packet you've like to send

and I think it will be all done.

RE: my bluetooth gets disconnected while sending continous stream of data

Deepak Kumar — Thu, 17 Mar 2016 20:53:13 GMT

hi mango, thanks for your help. your example send data continuously. the issue i am facing is i want to send live sensor data continuously. data keeps changing each time. this example is capable of sending same data itrating. but in my case i am sending different data continuously without iteration.

kindly guide me in that aspect.

thanks!!

RE: my bluetooth gets disconnected while sending continous stream of data

MANGO — Sun, 13 Mar 2016 18:28:03 GMT

Thanks for waiting. I'm using codes from SDK 7.2 so modify the code for SDK 10.

Also, your source files might be seperated from BLE handling parts.

So you have to manage global variables to take care of this.

You might have to change your sendData function too.

The concept is quite simple. I referenced this trick from the devzone a year ago. I will post the link later if I find it.

After you used ble_nus_string_send and successfully sends a string, on_ble_evt and

other dispatching functions are called for the BLE_EVT_TX_COMPLETE.

Using this feature, you can make an iterating loop to "continuously" send multiple data.

I will give you an example below so modify it for your own.

// global variable
bool       m_do_nus_iteration = false;
uint16_t m_iter = 5; // number of iteration
// ... now suppose you called ble_nus_string_send somewhere
void foo(void) {
             uint32_t err_code = ble_nus_string_send(&m_nus, "Start now", 9);
             APP_ERROR_CHECK(err_code);
             m_do_nus_iteration = true;
}

After the string "Start now" has successfully arrived at the central device,

your peripheral now has the BLE_EVT_TX_COMPLETE event.

Check this sequence chart if you want more info about BLE_EVT_TX_COMPLETE.

extern bool m_do_nus_iteration;
// in case, your UART handling functions are at seperate source file

void on_ble_evt(ble_evt_t * p_ble_evt) {
        switch (p_ble_evt->header.evt_id){
                       
                 case BLE_EVT_TX_COMPLETE: //at ble.h
                            // to distinguish whether this event happend due to ble_nus_string_send
                            if(m_do_nus_iteration) 
                                 my_nus_iter();
                                 break;
                 // for instance, I don't want this to start when I send Heart Rate Service packets
// ...
}

Lastly, this will send ABCD 4 times. After it succeeds sending, it will send again and again.

Hope you get the idea here.

However, I may have made some mistakes at the my_nus_iter function, so take some inspections.

extern uint16_t m_iter;
extern bool       m_do_nus_iteration;
void my_nus_iter(void) {

uint32_t err_code;

if(m_iter != 0) {
      err_code = ble_nus_string_send(&m_nus, "ABCD", 4);
      if (err_code == BLE_ERROR_NO_TX_BUFFERS ||
              err_code == NRF_ERROR_INVALID_STATE ||
              err_code == BLE_ERROR_GATTS_SYS_ATTR_MISSING) {
              return;
} // I experienced BLE_ERROR_NO_TX_BUFFERS at here
    
else if (err_code != NRF_SUCCESS) {
       APP_ERROR_CHECK(err_code);
 }

if(m_iter-- == 0) m_do_nus_iteration = false; // finished sending X times. So stop.
}

Hope you have understand how it works.

A similar question like this one can be a help to you.

Also, I wish you to reveal what caused the reset.

// Edited, Added at 23, March, 2016

Sorry that I cannot give you the full code you want.

However, I believe you can makes some changes and satisfy your needs.

I referenced this link so this will be more helpful to you.

-Best Regards, Mango922

RE: my bluetooth gets disconnected while sending continous stream of data

Deepak Kumar — Sun, 13 Mar 2016 08:06:48 GMT

yes you are right, i am taking data as multiple of 3 byte which is a midi data. and timer i used to append data upto 20 byte because i can send maximum of 20 byte. while printing the output it gives output with correct timer value. but after connecting to device the current time gives 0 due to which no data is being appened upto 20 byte.

RE: my bluetooth gets disconnected while sending continous stream of data

MANGO — Sun, 13 Mar 2016 06:31:37 GMT

Hmm, alright. I will just check again about your program is doing

because I don't know exactly your output is. I guess it's creating frequency and a piezo or speaker makes sounds since you wrote midiData.

You press keyboard button from your computer while you run a terminal program. ->

UART Interrupt is called. Also, it calculates the elapsed time or whatever it is. ->

Then midiData is created and you want to see the value via BLE NUS at your phone, is it?

/**********************************/

I will post an answer how to send multiple NUS packets soon.

Before posting, please note me if I understood your code.

Also, I think the reason of reset is that the timer or UART handling process is too long.

I wish you can check when your code calls NVIC reset.

RE: my bluetooth gets disconnected while sending continous stream of data

Deepak Kumar — Sat, 12 Mar 2016 18:32:49 GMT

hi, actually i am new to ble development. i am printing only to see the output of my program. i am sending the data using sendData() function in the program

void sendData(uint8_t data[],int index)
{
	uint32_t err_code;
	err_code = ble_nus_string_send(&m_nus, data, index);
                if (err_code != NRF_ERROR_INVALID_STATE)
                {
                    APP_ERROR_CHECK(err_code);
                }
}

please explain me how can i send continuous data using this way. or is there any other way to do this.

and yes app_timer_cnt_diff_compute i am using from SDK 10 only. one more issue i am having regarding timer. after connecting to peripheral device timer always gives 0. can you explain me why it is so. and how can i get time after connecting.

thanks!!

RE: my bluetooth gets disconnected while sending continous stream of data

MANGO — Sat, 12 Mar 2016 17:46:51 GMT

Oh, you are meaning that you continuously print debugging logs to the terminal program via UART?

I thought you were sending BLE NUS packets to the central continuously. My mistake.

Is the app_timer_cnt_diff_compute from SDK 10 or is it your personal function?

I used SDK 7.2 most of the time, so it will take a while to check.

Then what function returns an error code to make your device to reset?

Since I don't know your purpose of your code (and will take quite a time),

I think checking the error number will solve the problem.

Place a breakpoint at app_error_handler to check the error number and call stack before calling NVIC reset.

If you are using IAR EWARM, go to view -> call stack (while debugging), and it will reveal what functions are called.

By the way, are you using a Eval board or a custom board? Also do you use the scheduler from the SDK?

RE: my bluetooth gets disconnected while sending continous stream of data

Deepak Kumar — Sat, 12 Mar 2016 17:32:45 GMT

hi, yes you are right i am using like this only in switch loop my data get updated each time. and device resets and disconnects.

btw here is my code i am using to send data. and i am using 10 sdk NUS example.

case APP_UART_DATA_READY:
            UNUSED_VARIABLE(app_uart_get(&data_array[index]));
            index++;
						push++;
						if(index%3 == 0)
						{
							count++;
							err_code = app_timer_cnt_get(&uart_time);
							APP_ERROR_CHECK(err_code);
	
							uart_time = app_timer_ms(uart_time);
							sent_time = app_timer_ms(sent_time);
							duration_time = app_timer_ms(duration_time);
							
							//diff
							err_code = app_timer_cnt_diff_compute(uart_time,sent_time,&duration_time);
							APP_ERROR_CHECK(err_code);
							
							SEGGER_RTT_printf(0, "uart:%d\tsent:%d\tduration:%d\n",uart_time,sent_time,duration_time);
							//SEGGER_RTT_printf(0, "previous time:%d\n",previous_time);
							//SEGGER_RTT_printf(0, "duration time:\t%d\n",app_timer_ms(duration_time));
							
							
							
							
							SEGGER_RTT_printf(0, "current:%d\tsent:%d\n",uart_time,sent_time);
								
								if(uart_time<sent_time+waiting_time)
								{
										const uint8_t* midiData = parseMIDItoAppleBle(3, data_array);
										for(int i=0;i<5;i++)
										{
												data[i] = midiData[i];
										}
										SEGGER_RTT_printf(0, "%x\t%x\t%x\t%x\t%x\tcnt:%d\n",data[0], data[1],data[2],data[3], data[4],count);
										sendData(data,5);
										err_code = app_timer_cnt_get(&sent_time);
										APP_ERROR_CHECK(err_code);
								}
								
						
							index = 0;
							//rx_buf_num=0;

							//previous_time = current_time;
							preCount=count;
							//count=0;
						}

thanks!!

RE: my bluetooth gets disconnected while sending continous stream of data

MANGO — Sat, 12 Mar 2016 16:31:13 GMT

Hi, you might be using the NUS example. Can you tell me what SDK you are using?

Also can you tell me how you "send continuous stream"?

As you know, when using ble_nus_send_string, the maximum length is 20.

Are you calling ble_nus_send_string mutiple times like this?

for(uint16_t k = 0 ; k < 1000 ; k++) {
      err_code = ble_nus_send_string(&m_nus, (uint8_t *) "Hello World", 11);
      APP_ERROR_CHECK(err_code); // a bad way in my opinion
}

Or are you using BLE_EVT_TX_COMPLETE to taking care of this?

You will get an BLE_EVT_TX_COMPLETE every time a packet you have queued for transmission.

(ref. link)

Before I answer your question, I expect you'll get an error when calling ble_nus_send_string.

So the device resets and disconnects. Can you check the error code?