notification packet interval

[frogofmagic]

Hi, I got a problem.

I created a timer, interval is 30ms.

#define MIN_CONN_INTERVAL                MSEC_TO_UNITS(150, UNIT_10_MS)           /**< Minimum acceptable connection interval (0.02  seconds). */
#define MAX_CONN_INTERVAL                MSEC_TO_UNITS(400, UNIT_10_MS)           /**< Maximum acceptable connection interval (0.20  second). */


static void notify_timeout_handler(void * p_context){
  uint32_t err_code;
  uint8_t fifo_number;
  int fifo_get_data;	

  flag_30ms_interrupt = true;
	fifo_number = fifo_status(&m_FIFO); 

	if(ble_connect_status && fifo_number != 0 && m_nus.is_notification_enabled == true){
					
				if(can_get_new_fifo_array){
						fifo_get_data = fifo_get(&m_FIFO);
						for(int i=0;i<20;i++)
								nus_data_array[i] = ecg_fifo[m_FIFO.buf[fifo_get_data]]->data_array[i];
						nus_data_array_index = ecg_fifo[m_FIFO.buf[fifo_get_data]]->data_length;
						can_get_new_fifo_array = false;
					  
				}
				
				err_code = ble_nus_string_send(&m_nus, nus_data_array, nus_data_array_index);

				if (err_code == NRF_SUCCESS)
				{
						nus_data_array_index = 0;								//Data has been buffered in softdevice for transmission so we can write data_array with new data.
						can_get_new_fifo_array = true;
					  LEDS_INVERT(BSP_LED_0_MASK);
				}
				else if (err_code == NRF_ERROR_INVALID_STATE ||
						err_code == BLE_ERROR_NO_TX_PACKETS ||
						err_code == NRF_ERROR_BUSY)
				{
						//Do nothing. data_array still contains data for subsequent transmission. 
						//data_array content will be transmitted on another UART RX interrupt, TX_COMPLETE event or BLE services enabled event.
				}
				else
				{
						APP_ERROR_CHECK(err_code);
				}	
	}
}

Using SDK11, 51822, S130V2.

But when I using Lightblue app on iPhone6, sometimes the packet interval only 2~15ms.

13:06:32.053 notified:XXXXXXXXXXX

13:06:32.113 notified:XXXXXXXXXXX

13:06:32.114 notified:XXXXXXXXXXX

13:06:32.143 notified:XXXXXXXXXXX

My android engineers also got the same result on android phone. And they said it's too fast.

Is there any way I can do to avoid it? make it more stable?

[frogofmagic]

Ok, it seems I misunderstand min_conn_interval / max_conn_interval.

If I want notify every 30ms, the max_conn_interval should be less than 30ms.

I changed to

#define MIN_CONN_INTERVAL                MSEC_TO_UNITS(80, UNIT_10_MS)           /**< Minimum acceptable connection interval (0.008  seconds). */
#define MAX_CONN_INTERVAL                MSEC_TO_UNITS(100, UNIT_10_MS)           /**< Maximum acceptable connection interval (0.010  second). */

and problem seems solved.

Please let me know if I was doing the wrong thing >"<.