Problem in data transfer in Bluetooth at 10ms

[sharmelaraju]

Hi,

We are using NRF52840 Dk board to transfer the data at 10ms through Bluetooth which is central and peripheral  as other cc250moda controller  Bluetooth. Our objective is to send the data of 8 bytes at  10ms from the NRF52840 Bluetooth to other Bluetooth. We are able to send the data from NRF52840 Bluetooth of 8 bytes at 30ms,50ms,100ms,500 ms to other controller Bluetooth correctly which means at every 50ms  we are sending 8  of bytes data which is receiving  8 bytes of data at every 50ms in the receiving controller Bluetooth. The problem here is when we are sending the  8 bytes of data at 10ms from NRF52840  Bluetooth to  receiving Bluetooth it should read  8 bytes of data at 10ms but here the problem is it is reading as 8 bytes, 16 bytes ,24 bytes ,0 bytes ,0 bytes, 24 bytes,16 bytes, 0 bytes, 0 bytes  as such at every 10 ms.Can you please tell me what is the problem . How to resolve the issue.

[Karl Ylvisaker]

Hello,

I am not sure I understand exactly what you issue is here, other than the BLE communication not behaving as wanted.
Could you detail the issue some more, what parameter are you changing to differentiate between the different sending intervals? Could you share that snippet of your code?

Best regards,
Karl

[sharmelaraju]

Thanks for the reply.

I am here by attaching the code here at 10 ms.

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/**
 * @brief BLE LED Button Service central and client application main file.
 *
 * This file contains the source code for a sample client application using the LED Button service.
 */

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "nrf_sdh.h"
#include "nrf_sdh_ble.h"
#include "nrf_sdh_soc.h"
#include "nrf_pwr_mgmt.h"
#include "app_timer.h"
#include "boards.h"
#include "bsp.h"
#include "bsp_btn_ble.h"
#include "ble.h"
#include "ble_hci.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"
#include "ble_db_discovery.h"
#include "ble_lbs_c.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_scan.h"

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"



typedef unsigned char Byte_t;                   /* Generic 8 bit Container.   */



#define CENTRAL_SCANNING_LED            BSP_BOARD_LED_0                     /**< Scanning LED will be on when the device is scanning. */
#define CENTRAL_CONNECTED_LED           BSP_BOARD_LED_1                     /**< Connected LED will be on when the device is connected. */
#define LEDBUTTON_LED                   BSP_BOARD_LED_2                     /**< LED to indicate a change of state of the the Button characteristic on the peer. */

#define SCAN_INTERVAL                   0x00A0                              /**< Determines scan interval in units of 0.625 millisecond. */
#define SCAN_WINDOW                     0x0050                              /**< Determines scan window in units of 0.625 millisecond. */
#define SCAN_DURATION                   0x0000                              /**< Timout when scanning. 0x0000 disables timeout. */

#define MIN_CONNECTION_INTERVAL         MSEC_TO_UNITS(7.5, UNIT_1_25_MS)    /**< Determines minimum connection interval in milliseconds. */
#define MAX_CONNECTION_INTERVAL         MSEC_TO_UNITS(30, UNIT_1_25_MS)     /**< Determines maximum connection interval in milliseconds. */
#define SLAVE_LATENCY                   0                                   /**< Determines slave latency in terms of connection events. */
#define SUPERVISION_TIMEOUT             MSEC_TO_UNITS(4000, UNIT_10_MS)     /**< Determines supervision time-out in units of 10 milliseconds. */

#define LEDBUTTON_BUTTON_PIN            BSP_BUTTON_0                        /**< Button that will write to the LED characteristic of the peer */
#define BUTTON_DETECTION_DELAY          APP_TIMER_TICKS(50)                 /**< Delay from a GPIOTE event until a button is reported as pushed (in number of timer ticks). */

#define APP_BLE_CONN_CFG_TAG            1                                   /**< A tag identifying the SoftDevice BLE configuration. */
#define APP_BLE_OBSERVER_PRIO           3                                   /**< Application's BLE observer priority. You shouldn't need to modify this value. */

NRF_BLE_SCAN_DEF(m_scan);                                       /**< Scanning module instance. */
BLE_LBS_C_DEF(m_ble_lbs_c);                                     /**< Main structure used by the LBS client module. */
NRF_BLE_GATT_DEF(m_gatt);                                       /**< GATT module instance. */
BLE_DB_DISCOVERY_DEF(m_db_disc);                                /**< DB discovery module instance. */
#define BLE_NUS_MAX_DATA_LEN            8

//static char const m_target_periph_name[] = "Nordic_Blinky";     /**< Name of the device we try to connect to. This name is searched in the scan report data*/

static char const m_target_periph_name[] = "DEVICE";     /**< Name of the device we try to connect to. This name is searched in the scan report data*/

#define BATTERY_LEVEL_MEAS_INTERVAL         APP_TIMER_TICKS(10)                   /**< Battery level measurement interval (ticks). */

APP_TIMER_DEF(m_battery_timer_id);  

/**@brief Function to handle asserts in the SoftDevice.
 *
 * @details This function will be called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and does not fit a final product. You need to analyze
 *          how your product is supposed to react in case of Assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num     Line number of the failing ASSERT call.
 * @param[in] p_file_name  File name of the failing ASSERT call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
{
    app_error_handler(0xDEADBEEF, line_num, p_file_name);
}


/**@brief Function for the LEDs initialization.
 *
 * @details Initializes all LEDs used by the application.
 */
static void leds_init(void)
{
    bsp_board_init(BSP_INIT_LEDS);
}


/**@brief Function to start scanning.
 */
static void scan_start(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_scan_start(&m_scan);
    APP_ERROR_CHECK(err_code);

    bsp_board_led_off(CENTRAL_CONNECTED_LED);
    bsp_board_led_on(CENTRAL_SCANNING_LED);
}


/**@brief Handles events coming from the LED Button central module.
 */
static void lbs_c_evt_handler(ble_lbs_c_t * p_lbs_c, ble_lbs_c_evt_t * p_lbs_c_evt)
{
    switch (p_lbs_c_evt->evt_type)
    {
        case BLE_LBS_C_EVT_DISCOVERY_COMPLETE:
        {
            ret_code_t err_code;

            err_code = ble_lbs_c_handles_assign(&m_ble_lbs_c,
                                                p_lbs_c_evt->conn_handle,
                                                &p_lbs_c_evt->params.peer_db);
            NRF_LOG_INFO("LED Button service discovered on conn_handle 0x%x.", p_lbs_c_evt->conn_handle);

            err_code = app_button_enable();
            APP_ERROR_CHECK(err_code);

            // LED Button service discovered. Enable notification of Button.
            err_code = ble_lbs_c_button_notif_enable(p_lbs_c);
            APP_ERROR_CHECK(err_code);
        } break; // BLE_LBS_C_EVT_DISCOVERY_COMPLETE

        case BLE_LBS_C_EVT_BUTTON_NOTIFICATION:
        {
            NRF_LOG_INFO("Button state changed on peer to 0x%x.", p_lbs_c_evt->params.button.button_state);
            if (p_lbs_c_evt->params.button.button_state)
            {
                bsp_board_led_on(LEDBUTTON_LED);
            }
            else
            {
                bsp_board_led_off(LEDBUTTON_LED);
            }
        } break; // BLE_LBS_C_EVT_BUTTON_NOTIFICATION

        default:
            // No implementation needed.
            break;
    }
}

void send_ble_data(uint8_t * p_data, uint16_t length)
{
static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
memcpy(data_array, p_data, length);
ble_nus_c_string_send(&m_ble_lbs_c, data_array, length);
}
/**@brief Function for handling the Battery measurement timer timeout.
 *
 * @details This function will be called each time the battery level measurement timer expires.
 *
 * @param[in] p_context  Pointer used for passing some arbitrary information (context) from the
 *                       app_start_timer() call to the timeout handler.
 */
static void battery_level_meas_timeout_handler(void * p_context)
{
    UNUSED_PARAMETER(p_context);
    

	uint8_t var=0;
	static int seq=0;
	Byte_t dummyData[8];		// the data packet.
//	static int seq;
//	int crc=0,crc1=0;					//WARNING----- DO NOT INTERCHANGE THIS AND BELOW THIS ONE. IF IT IS NOT IN THIS ORDER, YOU WILL
//	uint8_t crc_i=0;					// GET ERROR IN ANDROID SIDE OF CRC. LET THIS AND ABOVE THIS, BE LIKE THIS ONLY.
	//11-4-18--11:30am--- i think dat error is coz i didnt initialize crc to 0. now i did and crc error gone. so, maybe you can
	// ignore the warning. Anyway, I won't change those things as I dont want to take risk. Upto you to decide what you wanna do.

	//int crc,crc1=0; changed to int from int16_t(or somethign, refer in my main codes v2.10 or something). now crc error stopped.
	//13-3-18-- crc error was getting after doing service mode. so, did this above change now to stop the error.



	//--------------------------------------forming data packet-----------------------------------


	for(var=0;var<=8;var++) 			// to form 6 byte data-packet format
	{
		switch(var)
		{
			case 0:							//indication bit whther it's data or command.

				dummyData[var]=0x12; 				// 0 indicates, it's data ( for command=1)
				break;


			case 1:							//for ibp middle. ignore ibp MSB

				dummyData[var]=0x13;
				break;

			case 2:							//ibp LSB

				dummyData[var]=0x15;
				break;

			case 3:							//for ibp middle. ignore ibp MSB

			    dummyData[var]=0x16;
				break;


			case 4:										// for  sequence numbers

				dummyData[var]=0x18;
					break;
				
		 case 5:										// for  sequence numbers

				dummyData[var]=0x17;
				break;

			case 6:										// for  sequence numbers

				dummyData[var]=0x11;
				break;

			case 7:										// for  sequence numbers

				dummyData[var]=seq;
				seq++; // it will go from 0 to 124
				if(seq==20)
				{
					seq=0;
				}
				break;
			}
		}
	
send_ble_data(dummyData, sizeof(dummyData));
	
}


/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    ret_code_t err_code;

    // For readability.
    ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt;

    switch (p_ble_evt->header.evt_id)
    {
        // Upon connection, check which peripheral has connected (HR or RSC), initiate DB
        // discovery, update LEDs status and resume scanning if necessary. */
        case BLE_GAP_EVT_CONNECTED:
        {
            NRF_LOG_INFO("Connected.\r\n");
            err_code = ble_lbs_c_handles_assign(&m_ble_lbs_c, p_gap_evt->conn_handle, NULL);
            APP_ERROR_CHECK(err_code);

            err_code = ble_db_discovery_start(&m_db_disc, p_gap_evt->conn_handle);
            APP_ERROR_CHECK(err_code);
					  if(err_code==NRF_SUCCESS)
						{
							NRF_LOG_INFO("DISCOVERY COMPLETED\r\n");
            
						}

            // Update LEDs status, and check if we should be looking for more
            // peripherals to connect to.
            bsp_board_led_on(CENTRAL_CONNECTED_LED);
            bsp_board_led_off(CENTRAL_SCANNING_LED);
        } break;

        // Upon disconnection, reset the connection handle of the peer which disconnected, update
        // the LEDs status and start scanning again.
        case BLE_GAP_EVT_DISCONNECTED:
        {
            NRF_LOG_INFO("Disconnected.");
            scan_start();
        } break;

        case BLE_GAP_EVT_TIMEOUT:
        {
            // We have not specified a timeout for scanning, so only connection attemps can timeout.
            if (p_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_CONN)
            {
                NRF_LOG_INFO("Connection request timed out.");
            }
        } break;

        case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
        {
            // Accept parameters requested by peer.
            err_code = sd_ble_gap_conn_param_update(p_gap_evt->conn_handle,
                                        &p_gap_evt->params.conn_param_update_request.conn_params);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_INFO("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTC_EVT_TIMEOUT:
        {
            // Disconnect on GATT Client timeout event.
            NRF_LOG_INFO("GATT Client Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTS_EVT_TIMEOUT:
        {
            // Disconnect on GATT Server timeout event.
            NRF_LOG_INFO("GATT Server Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
        } break;
				
         case BLE_GATTS_EVT_SYS_ATTR_MISSING:
            // No system attributes have been stored.
            err_code = sd_ble_gatts_sys_attr_set(p_ble_evt->evt.gatts_evt.conn_handle, NULL, 0, 0);
            APP_ERROR_CHECK(err_code);
        default:
            // No implementation needed.
            break;
    }
}

/**@brief Function for starting application timers.
 */
static void application_timers_start(void)
{
    ret_code_t err_code;

    // Start application timers.
    err_code = app_timer_start(m_battery_timer_id, BATTERY_LEVEL_MEAS_INTERVAL, NULL);
    APP_ERROR_CHECK(err_code);
}

/**@brief LED Button client initialization.
 */
static void lbs_c_init(void)
{
    ret_code_t       err_code;
    ble_lbs_c_init_t lbs_c_init_obj;

    lbs_c_init_obj.evt_handler = lbs_c_evt_handler;

    err_code = ble_lbs_c_init(&m_ble_lbs_c, &lbs_c_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupts.
 */
static void ble_stack_init(void)
{
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
}


/**@brief Function for handling events from the button handler module.
 *
 * @param[in] pin_no        The pin that the event applies to.
 * @param[in] button_action The button action (press/release).
 */
static void button_event_handler(uint8_t pin_no, uint8_t button_action)
{
    ret_code_t err_code;

    switch (pin_no)
    {
        case LEDBUTTON_BUTTON_PIN:
            err_code = ble_lbs_led_status_send(&m_ble_lbs_c, button_action);
            if (err_code != NRF_SUCCESS &&
                err_code != BLE_ERROR_INVALID_CONN_HANDLE &&
                err_code != NRF_ERROR_INVALID_STATE)
            {
                APP_ERROR_CHECK(err_code);
            }
            if (err_code == NRF_SUCCESS)
            {
                NRF_LOG_INFO("LBS write LED state %d", button_action);
            }
            break;

        default:
            APP_ERROR_HANDLER(pin_no);
            break;
    }
}


/**@brief Function for handling Scaning events.
 *
 * @param[in]   p_scan_evt   Scanning event.
 */
static void scan_evt_handler(scan_evt_t const * p_scan_evt)
{
    ret_code_t err_code;

    switch(p_scan_evt->scan_evt_id)
    {
        case NRF_BLE_SCAN_EVT_CONNECTING_ERROR:
            err_code = p_scan_evt->params.connecting_err.err_code;
            APP_ERROR_CHECK(err_code);
            break;
        default:
          break;
    }
}



/**@brief Function for initializing the button handler module.
 */
static void buttons_init(void)
{
    ret_code_t err_code;

    //The array must be static because a pointer to it will be saved in the button handler module.
    static app_button_cfg_t buttons[] =
    {
        {LEDBUTTON_BUTTON_PIN, false, BUTTON_PULL, button_event_handler}
    };

    err_code = app_button_init(buttons, ARRAY_SIZE(buttons),
                               BUTTON_DETECTION_DELAY);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling database discovery events.
 *
 * @details This function is callback function to handle events from the database discovery module.
 *          Depending on the UUIDs that are discovered, this function should forward the events
 *          to their respective services.
 *
 * @param[in] p_event  Pointer to the database discovery event.
 */
static void db_disc_handler(ble_db_discovery_evt_t * p_evt)
{
    ble_lbs_on_db_disc_evt(&m_ble_lbs_c, p_evt);
}


/**@brief Database discovery initialization.
 */
static void db_discovery_init(void)
{
    ret_code_t err_code = ble_db_discovery_init(db_disc_handler);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the log.
 */
static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


/**@brief Function for initializing the timer.
 */
static void timer_init(void)
{
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
	 err_code = app_timer_create(&m_battery_timer_id,
                                APP_TIMER_MODE_REPEATED,
                                battery_level_meas_timeout_handler);
    APP_ERROR_CHECK(err_code);

}


/**@brief Function for initializing the Power manager. */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


static void scan_init(void)
{
    ret_code_t          err_code;
    nrf_ble_scan_init_t init_scan;

    memset(&init_scan, 0, sizeof(init_scan));

    init_scan.connect_if_match = true;
    init_scan.conn_cfg_tag     = APP_BLE_CONN_CFG_TAG;

    err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
    APP_ERROR_CHECK(err_code);

    // Setting filters for scanning.
    err_code = nrf_ble_scan_filters_enable(&m_scan, NRF_BLE_SCAN_NAME_FILTER, false);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_NAME_FILTER, m_target_periph_name);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the GATT module.
 */
static void gatt_init(void)
{
    ret_code_t err_code = nrf_ble_gatt_init(&m_gatt, NULL);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop).
 *
 * @details Handle any pending log operation(s), then sleep until the next event occurs.
 */
static void idle_state_handle(void)
{
    NRF_LOG_FLUSH();
    nrf_pwr_mgmt_run();
}


int main(void)
{
    // Initialize.
    log_init();
    timer_init();
    leds_init();
    buttons_init();
    power_management_init();
    ble_stack_init();
    scan_init();
    gatt_init();
    db_discovery_init();
    lbs_c_init();

    // Start execution.
    NRF_LOG_INFO("Blinky CENTRAL example started.");
    scan_start();

    // Turn on the LED to signal scanning.
    bsp_board_led_on(CENTRAL_SCANNING_LED);
	  application_timers_start();

    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
    }
}

please give me the solution.

[Karl Ylvisaker]

Hello,

Your connection interval is from 7.5 to 30 ms, try changing this to something that will ensure connections happens often enough to move your data. If both your devices support 10 ms connection interval, and your central only speaks to a single peripheral, then you could also change the interval to exactly 10 ms.

The packets are not sent as soon as you call the ble_nus_send_data function, but rather at the next connection, as per the BLE specification.

However, be advised that some devices does not support < 15 ms connection interval(android/iOS), so you need to verify that your cc250moda controller supports this.

Let me know if this solves your problems,

Best regards,
Karl

[sharmelaraju]

Hi,

Thanks for the reply.

I have tried to change the connection interval from 10 to 20ms. Stil i am  not able to read the 8 bytes of data at every 10ms.

The CC2564MODA Bluetooth do support 10ms connection interval.

still i am not getting solution. Plz help me in this 

[Karl Ylvisaker]

Hello,

The specified connection interval minimum and maximum is a range that is given to the central to choose from during the connection parameter negotiation. That means that your central might still be choosing 20 ms connection intervals.
The reason why the connection interval is given as a range is so that the central can communicate with multiple devices - but this is not needed for your application, if you are only communicating with one peripheral.

In order to ensure that you get exactly 10 ms connection interval, you need to define both the minimum and maximum interval length to 10 ms. Could you try this, and let me know if it solves your problem?
And, if it does not, please specify what you are seeing with the changes in place; is the packets arriving, but at the wrong interval, or are they not arriving at all, etc.

Best regards,
Karl

[sharmelaraju]

Thanks for the reply.

As you said i have changed the minimum and maximum connection interval to 10 ms.

The problem here is the packets are arriving,here i get notification as i receive the data but reading the data as 8 bytes,24 bytes,16 bytes.

But at 100ms it working fine which means it is getting notification and at the same time it is reading the data.Here is the console log which is receiving at 100ms.

SPP+LE>
18:17:29.975: Read: 8.
data== [12][13][15][16][18][17][11][06]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:30.080: Read: 8.
data== [12][13][15][16][18][17][11][07]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:30.190: Read: 8.
data== [12][13][15][16][18][17][11][08]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:30.302: Read: 8.
data== [12][13][15][16][18][17][11]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:30.412: Read: 8.
data== [12][13][15][16][18][17][11]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:30.518: Read: 8.
data== [12][13][15][16][18][17][11][0B]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:30.629: Read: 8.
data== [12][13][15][16][18][17][11][0C]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:30.641: Read: 8.
data== [12][13][15][16][18][17][11]
18:17:30.650:

18:17:30.739:
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>R
18:17:30.751: ead: 8.
data== [12][13][15][16][18][17][11][0E]

Data Indicatio
18:17:30.763: n Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:30.845: Read: 8.
data== [12][13][15][16][18][17][11][0F]

Data Indication Event, Connection ID 1, Rec
18:17:30.858: eived 8 bytes.

SPP+LE>
18:17:30.959: Read: 8.
data== [12][13][15][16][18][17][11][10]
18:17:30.971:
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:31.069: Read: 8.
data== [12][13][15][16][18][17][11][11]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:31.179: Read: 8.
data== [12][13][15][16][18][17][11][12]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:17:31.284: Read: 8.
data== [12][13][15][16][18][17][11][13].

Here is the console log which is received at 10ms.

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0B][12][13][15][16][18][17][11][0C][12][13][15][16][18][17][11]

Read: 0.

Read: 0.

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0E][12][13][15][16][18][17][11][0F][12][13][15][16][18][17][11][10]
Read: 0.

Read: 0.

Data Indication Event, Connection
18:33:16.050: ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][11][12][13][15][16][18][17][11][12][12][13][15][16][18][17][11][13]
Read: 0.

Read: 0.

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11]
Read: 0.

Read: 0.

18:33:16.060: Read: 0.

18:33:16.146: Read: 0.

Read: 0.

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 40.
data== [12][13][15][16][18][17][11][03][12][13][15][16][18][17][11][04][12][13][15][16][18][17][11][05][12][13][15][16][18][17][11][06][12][13][15][16][18][17][11][07]

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 16.
data== [12][13][15][16][18][17][11][08][12][13][15][16][18][17][11]
Read: 0.

Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Conn
18:33:16.158: ection ID 1, Received 8 bytes.

SPP+LE>Read: 16.
data== [12][13][15][16][18][17][11]
[12][13][15][16][18][17][11][0B]
Read: 0.

Read: 0.

Data Indication Event, Connection
18:33:16.167: ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE
18:33:16.175: >
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17]
18:33:16.183: [11][0C][12][13][15][16][18][17][11]
[12][13][15][16][18][17][11][0E]
Read: 0.

Read: 0.

Data Indication Event, Connection ID 1, Rec
18:33:16.191: eived 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
18:33:16.200:
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0F][12][13][15][16][18][17][11][10]
18:33:16.209: [12][13][15][16][18][17][11][11]
Read: 0.

Read: 0.

Data Indication Event, Connection ID 1, Receiv
18:33:16.217: ed 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Da
18:33:16.225: ta Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16]
18:33:16.233: [18][17][11][12][12][13][15][16][18][17][11][13][12][13][15][16][18][17][11]
Read: 0.

Read: 0.

18:33:16.240:
Data Indication Event, Connection ID 1, Receive
18:33:16.248: d 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Da
18:33:16.254: ta Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read:
18:33:16.262: 24.
data== [12][13][15][16][18][17][11][01][12][13][15][16][18][17][11][02][12][13][15][16][18][17][11][03]
Read: 0.

Read: 0.

18:33:16.268:
Data Indication Event, Connect
18:33:16.275: ion ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1,
18:33:16.282: Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8
18:33:16.289: bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][04][12][13][15][16][18][17][11][05][12][13][15][16][18][17][11][06]
Read: 0.

Read: 0
18:33:16.295: .

18:33:16.302:
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Ind
18:33:16.308: ication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indic
18:33:16.314: ation Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 2
18:33:16.323: 4.
data== [12][13][15][16][18][17][11][07][12][13][15][16][18][17][11][08][12][13][15][16][18][17][11]
Read: 0.

Read: 0.

18:33:16.330:
Data Indication Event, Connection ID 1, Received 8 byte
18:33:16.339: s.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Ev
18:33:16.347: ent, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11]
[12][13][15][16][18][17][11][0B][12][13][15][16]
18:33:16.355: [18][17][11][0C]
Read: 0.

Read: 0.

18:33:16.363:
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication
18:33:16.369: Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indica
18:33:16.375: tion Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16]
18:33:16.383: [18][17][11]
[12][13][15][16][18][17][11][0E][12][13][15][16][18][17][11][0F]
Read: 0.

Read: 0.

18:33:16.391:
Data Indication Event, Connection ID 1, Received 8 bytes.

S
18:33:16.398: PP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Da
18:33:16.405: ta Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18]
18:33:16.414: [17][11][10][12][13][15][16][18][17][11][11][12][13][15][16][18][17][11][12]
Read: 0.

Read: 0.

18:33:16.422:
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
D
18:33:16.430: ata Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Conn
18:33:16.437: ection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][13][12][13][15][16][18][17][11]
Read
18:33:16.446: : 0.

Read: 0.

Data I
18:33:16.455: ndication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1,
18:33:16.463: Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+L
18:33:16.471: E>Read: 24.
data== [12][13][15][16][18][17][11][02][12][13][15][16][18][17][11][03][12][13][15][16][18][17][11][04]
Read: 0.

Read: 0.

18:33:16.478:
Data Indication Event, Connect
18:33:16.485: ion ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1,
18:33:16.492: Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8
18:33:16.499: bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][05][12][13][15][16][18][17][11][06][12][13][15][16][18][17][11][07]
Read: 0.

Read:
18:33:16.507: 0.

Data Indicatio
18:33:16.515: n Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1,
18:33:16.522: Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8
18:33:16.530: bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][08][12][13][15][16][18][17][11] [12][13][15][16][18][17][11]

Read: 0.

Read: 0.

18:33:16.538:
Data Indication Event, Connection ID 1
18:33:16.547: , Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP
18:33:16.554: +LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read:
18:33:16.562: 24.
data== [12][13][15][16][18][17][11][0B][12][13][15][16][18][17][11][0C][12][13][15][16][18][17][11]

Read: 0.

Read: 0.

18:33:16.570:
Data Indication Event, Connection ID 1, Received 8 byt
18:33:16.579: es.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indic
18:33:16.587: ation Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0E][12][13][15][16][18][17][11][0F][12][13][15][16]
18:33:16.594: [18][17][11][10]
Read: 0.

Read: 0.

please give me the solution

[Karl Ylvisaker]

sharmelaraju said:

please give me the solution

I would love to be able to do that, but it might not be that easy. Your peripheral code seems fine, and the logs indicate that the data is received roughly every 7.5 ms.

Could you verify that the problem is not on your central-side?
From the logs it seems that the data is received at the right time, but not processed. Please make sure that the central has enough time to complete all its tasks and interrupts in time. You could do this by stopping all other tasks that the central is doing, and just handling the received data. Please bear in mind that I do not know what you are doing on your central side of this.
You could also print out some debug messages with timestamps on your peripheral, to verify that the transfers are happening at the right time.

I also notice that the log you have copied into your reply seems incomplete, with some timestamps cut short and some other readouts formatting improperly. To avoid wasting time deciphering that some content is missing, please make sure that the logs you provide are complete.

For future reference, please make use of the insert option when posting code or logs as a comment, or export logs as separate files to include with your reply. This makes them much easier to read.

Looking forward to resolving your issue,

Best regards,
Karl

[sharmelaraju]

Thank you for the support.

The central is NRF52840 (Central) and the peripheral is CC2564MODA Bluetooth(TM4C controller).I am sending 8 bytes of data at every 10 ms from the NRF52840 (central )to  the peripheral which has to receive 8 bytes of data at every 10 ms.

I am here by attaching the central code which i have commented all the tasks except sending of 8 bytes of data at every 10ms.Please check the code and let me know if there is any changes isrequired.

/**
 * Copyright (c) 2014 - 2019, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
/**
 * @brief BLE LED Button Service central and client application main file.
 *
 * This file contains the source code for a sample client application using the LED Button service.
 */

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "nrf_sdh.h"
#include "nrf_sdh_ble.h"
#include "nrf_sdh_soc.h"
#include "nrf_pwr_mgmt.h"
#include "app_timer.h"
#include "boards.h"
#include "bsp.h"
#include "bsp_btn_ble.h"
#include "ble.h"
#include "ble_hci.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"
#include "ble_db_discovery.h"
#include "ble_lbs_c.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_scan.h"

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"



typedef unsigned char Byte_t;                   /* Generic 8 bit Container.   */



#define CENTRAL_SCANNING_LED            BSP_BOARD_LED_0                     /**< Scanning LED will be on when the device is scanning. */
#define CENTRAL_CONNECTED_LED           BSP_BOARD_LED_1                     /**< Connected LED will be on when the device is connected. */
#define LEDBUTTON_LED                   BSP_BOARD_LED_2                     /**< LED to indicate a change of state of the the Button characteristic on the peer. */

#define SCAN_INTERVAL                   0x00A0                              /**< Determines scan interval in units of 0.625 millisecond. */
#define SCAN_WINDOW                     0x0050                              /**< Determines scan window in units of 0.625 millisecond. */
#define SCAN_DURATION                   0x0000                              /**< Timout when scanning. 0x0000 disables timeout. */

#define MIN_CONNECTION_INTERVAL         MSEC_TO_UNITS(10, UNIT_1_25_MS)    /**< Determines minimum connection interval in milliseconds. */
#define MAX_CONNECTION_INTERVAL         MSEC_TO_UNITS(10, UNIT_1_25_MS)     /**< Determines maximum connection interval in milliseconds. */
#define SLAVE_LATENCY                   0                                   /**< Determines slave latency in terms of connection events. */
#define SUPERVISION_TIMEOUT             MSEC_TO_UNITS(4000, UNIT_10_MS)     /**< Determines supervision time-out in units of 10 milliseconds. */

#define LEDBUTTON_BUTTON_PIN            BSP_BUTTON_0                        /**< Button that will write to the LED characteristic of the peer */
#define BUTTON_DETECTION_DELAY          APP_TIMER_TICKS(50)                 /**< Delay from a GPIOTE event until a button is reported as pushed (in number of timer ticks). */

#define APP_BLE_CONN_CFG_TAG            1                                   /**< A tag identifying the SoftDevice BLE configuration. */
#define APP_BLE_OBSERVER_PRIO           3                                   /**< Application's BLE observer priority. You shouldn't need to modify this value. */

NRF_BLE_SCAN_DEF(m_scan);                                       /**< Scanning module instance. */
BLE_LBS_C_DEF(m_ble_lbs_c);                                     /**< Main structure used by the LBS client module. */
NRF_BLE_GATT_DEF(m_gatt);                                       /**< GATT module instance. */
BLE_DB_DISCOVERY_DEF(m_db_disc);                                /**< DB discovery module instance. */
#define BLE_NUS_MAX_DATA_LEN            8

//static char const m_target_periph_name[] = "Nordic_Blinky";     /**< Name of the device we try to connect to. This name is searched in the scan report data*/

static char const m_target_periph_name[] = "DEVICE";     /**< Name of the device we try to connect to. This name is searched in the scan report data*/

#define BATTERY_LEVEL_MEAS_INTERVAL         APP_TIMER_TICKS(10)                   /**< Battery level measurement interval (ticks). */

APP_TIMER_DEF(m_battery_timer_id);  

/**@brief Function to handle asserts in the SoftDevice.
 *
 * @details This function will be called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and does not fit a final product. You need to analyze
 *          how your product is supposed to react in case of Assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num     Line number of the failing ASSERT call.
 * @param[in] p_file_name  File name of the failing ASSERT call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
{
    app_error_handler(0xDEADBEEF, line_num, p_file_name);
}


/**@brief Function for the LEDs initialization.
 *
 * @details Initializes all LEDs used by the application.
 */
static void leds_init(void)
{
    bsp_board_init(BSP_INIT_LEDS);
}


/**@brief Function to start scanning.
 */
static void scan_start(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_scan_start(&m_scan);
    APP_ERROR_CHECK(err_code);

    bsp_board_led_off(CENTRAL_CONNECTED_LED);
    bsp_board_led_on(CENTRAL_SCANNING_LED);
}


/**@brief Handles events coming from the LED Button central module.
 */
static void lbs_c_evt_handler(ble_lbs_c_t * p_lbs_c, ble_lbs_c_evt_t * p_lbs_c_evt)
{
    switch (p_lbs_c_evt->evt_type)
    {
        case BLE_LBS_C_EVT_DISCOVERY_COMPLETE:
        {
            ret_code_t err_code;

            err_code = ble_lbs_c_handles_assign(&m_ble_lbs_c,
                                                p_lbs_c_evt->conn_handle,
                                                &p_lbs_c_evt->params.peer_db);
            NRF_LOG_INFO("LED Button service discovered on conn_handle 0x%x.", p_lbs_c_evt->conn_handle);

            err_code = app_button_enable();
            APP_ERROR_CHECK(err_code);

            // LED Button service discovered. Enable notification of Button.
            err_code = ble_lbs_c_button_notif_enable(p_lbs_c);
            APP_ERROR_CHECK(err_code);
        } break; // BLE_LBS_C_EVT_DISCOVERY_COMPLETE

       /* case BLE_LBS_C_EVT_BUTTON_NOTIFICATION:
        {
            NRF_LOG_INFO("Button state changed on peer to 0x%x.", p_lbs_c_evt->params.button.button_state);
            if (p_lbs_c_evt->params.button.button_state)
            {
                bsp_board_led_on(LEDBUTTON_LED);
            }
            else
            {
                bsp_board_led_off(LEDBUTTON_LED);
            }
        } break; // BLE_LBS_C_EVT_BUTTON_NOTIFICATION*/

        default:
            // No implementation needed.
            break;
    }
}

void send_ble_data(uint8_t * p_data, uint16_t length)
{
static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
memcpy(data_array, p_data, length);
ble_nus_c_string_send(&m_ble_lbs_c, data_array, length);
}
/**@brief Function for handling the Battery measurement timer timeout.
 *
 * @details This function will be called each time the battery level measurement timer expires.
 *
 * @param[in] p_context  Pointer used for passing some arbitrary information (context) from the
 *                       app_start_timer() call to the timeout handler.
 */
static void battery_level_meas_timeout_handler(void * p_context)
{
    UNUSED_PARAMETER(p_context);
    //battery_level_update();
	
uint8_t dummyData[8] ;

int i=0;	

nrf_gpio_pin_toggle(24);
	
dummyData[0]=0X11;
	
dummyData[1]=0X12;

dummyData[2]=0X23;
	
dummyData[3]=0X34;

dummyData[4]=0X55;
	
dummyData[5]=0X66;

dummyData[6]=0X57;
	
dummyData[7]=0x58;
//i++;
//if(i>=100)
//{
	//i=0;
//}


	/*uint8_t var=0;
	static int seq=0;
	Byte_t dummyData[8];		// the data packet.
//	static int seq;
//	int crc=0,crc1=0;					//WARNING----- DO NOT INTERCHANGE THIS AND BELOW THIS ONE. IF IT IS NOT IN THIS ORDER, YOU WILL
//	uint8_t crc_i=0;					// GET ERROR IN ANDROID SIDE OF CRC. LET THIS AND ABOVE THIS, BE LIKE THIS ONLY.
	//11-4-18--11:30am--- i think dat error is coz i didnt initialize crc to 0. now i did and crc error gone. so, maybe you can
	// ignore the warning. Anyway, I won't change those things as I dont want to take risk. Upto you to decide what you wanna do.

	//int crc,crc1=0; changed to int from int16_t(or somethign, refer in my main codes v2.10 or something). now crc error stopped.
	//13-3-18-- crc error was getting after doing service mode. so, did this above change now to stop the error.



	//--------------------------------------forming data packet-----------------------------------


	for(var=0;var<=8;var++) 			// to form 6 byte data-packet format
	{
		switch(var)
		{
			case 0:							//indication bit whther it's data or command.

				dummyData[var]=0x12; 				// 0 indicates, it's data ( for command=1)
				break;


			case 1:							//for ibp middle. ignore ibp MSB

				dummyData[var]=0x13;
				break;

			case 2:							//ibp LSB

				dummyData[var]=0x15;
				break;

			case 3:							//for ibp middle. ignore ibp MSB

			    dummyData[var]=0x16;
				break;


			case 4:										// for  sequence numbers

				dummyData[var]=0x18;
					break;
				
		 case 5:										// for  sequence numbers

				dummyData[var]=0x17;
				break;

			case 6:										// for  sequence numbers

				dummyData[var]=0x11;
				break;

			case 7:										// for  sequence numbers

				dummyData[var]=seq;
				seq++; // it will go from 0 to 124
				if(seq==20)
				{
					seq=0;
				}
				break;
			}
		}
	//ProcessCommandLine2(data,DATA_PACKET_SIZE); // this is in line 4307 in sppdemo.c*/

send_ble_data(dummyData, sizeof(dummyData));
	
}


/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    ret_code_t err_code;

    // For readability.
    ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt;

    switch (p_ble_evt->header.evt_id)
    {
        // Upon connection, check which peripheral has connected (HR or RSC), initiate DB
        // discovery, update LEDs status and resume scanning if necessary. */
        case BLE_GAP_EVT_CONNECTED:
        {
            NRF_LOG_INFO("Connected.\r\n");
            err_code = ble_lbs_c_handles_assign(&m_ble_lbs_c, p_gap_evt->conn_handle, NULL);
            APP_ERROR_CHECK(err_code);

            err_code = ble_db_discovery_start(&m_db_disc, p_gap_evt->conn_handle);
            APP_ERROR_CHECK(err_code);
					  if(err_code==NRF_SUCCESS)
						{
							NRF_LOG_INFO("DISCOVERY COMPLETED\r\n");
            
						}

            // Update LEDs status, and check if we should be looking for more
            // peripherals to connect to.
            bsp_board_led_on(CENTRAL_CONNECTED_LED);
            bsp_board_led_off(CENTRAL_SCANNING_LED);
        } break;

        // Upon disconnection, reset the connection handle of the peer which disconnected, update
        // the LEDs status and start scanning again.
        case BLE_GAP_EVT_DISCONNECTED:
        {
            NRF_LOG_INFO("Disconnected.");
            scan_start();
        } break;

        case BLE_GAP_EVT_TIMEOUT:
        {
            // We have not specified a timeout for scanning, so only connection attemps can timeout.
            if (p_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_CONN)
            {
                NRF_LOG_INFO("Connection request timed out.");
            }
        } break;

        case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
        {
            // Accept parameters requested by peer.
            err_code = sd_ble_gap_conn_param_update(p_gap_evt->conn_handle,
                                        &p_gap_evt->params.conn_param_update_request.conn_params);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_INFO("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTC_EVT_TIMEOUT:
        {
            // Disconnect on GATT Client timeout event.
            NRF_LOG_INFO("GATT Client Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTS_EVT_TIMEOUT:
        {
            // Disconnect on GATT Server timeout event.
            NRF_LOG_INFO("GATT Server Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
        } break;
				
         case BLE_GATTS_EVT_SYS_ATTR_MISSING:
            // No system attributes have been stored.
            err_code = sd_ble_gatts_sys_attr_set(p_ble_evt->evt.gatts_evt.conn_handle, NULL, 0, 0);
            APP_ERROR_CHECK(err_code);
        default:
            // No implementation needed.
            break;
    }
}

/**@brief Function for starting application timers.
 */
static void application_timers_start(void)
{
    ret_code_t err_code;

    // Start application timers.
    err_code = app_timer_start(m_battery_timer_id, BATTERY_LEVEL_MEAS_INTERVAL, NULL);
    APP_ERROR_CHECK(err_code);
}

/**@brief LED Button client initialization.
 */
static void lbs_c_init(void)
{
    ret_code_t       err_code;
    ble_lbs_c_init_t lbs_c_init_obj;

    lbs_c_init_obj.evt_handler = lbs_c_evt_handler;

    err_code = ble_lbs_c_init(&m_ble_lbs_c, &lbs_c_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupts.
 */
static void ble_stack_init(void)
{
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
}


/**@brief Function for handling events from the button handler module.
 *
 * @param[in] pin_no        The pin that the event applies to.
 * @param[in] button_action The button action (press/release).
 */
/*static void button_event_handler(uint8_t pin_no, uint8_t button_action)
{
    ret_code_t err_code;

    switch (pin_no)
    {
        case LEDBUTTON_BUTTON_PIN:
            err_code = ble_lbs_led_status_send(&m_ble_lbs_c, button_action);
            if (err_code != NRF_SUCCESS &&
                err_code != BLE_ERROR_INVALID_CONN_HANDLE &&
                err_code != NRF_ERROR_INVALID_STATE)
            {
                APP_ERROR_CHECK(err_code);
            }
            if (err_code == NRF_SUCCESS)
            {
                NRF_LOG_INFO("LBS write LED state %d", button_action);
            }
            break;

        default:
            APP_ERROR_HANDLER(pin_no);
            break;
    }
}
*/

/**@brief Function for handling Scaning events.
 *
 * @param[in]   p_scan_evt   Scanning event.
 */
static void scan_evt_handler(scan_evt_t const * p_scan_evt)
{
    ret_code_t err_code;

    switch(p_scan_evt->scan_evt_id)
    {
        case NRF_BLE_SCAN_EVT_CONNECTING_ERROR:
            err_code = p_scan_evt->params.connecting_err.err_code;
            APP_ERROR_CHECK(err_code);
            break;
        default:
          break;
    }
}



/**@brief Function for initializing the button handler module.
 */
/*static void buttons_init(void)
{
    ret_code_t err_code;

    //The array must be static because a pointer to it will be saved in the button handler module.
    static app_button_cfg_t buttons[] =
    {
        {LEDBUTTON_BUTTON_PIN, false, BUTTON_PULL, button_event_handler}
    };

    err_code = app_button_init(buttons, ARRAY_SIZE(buttons),
                               BUTTON_DETECTION_DELAY);
    APP_ERROR_CHECK(err_code);
}
*/

/**@brief Function for handling database discovery events.
 *
 * @details This function is callback function to handle events from the database discovery module.
 *          Depending on the UUIDs that are discovered, this function should forward the events
 *          to their respective services.
 *
 * @param[in] p_event  Pointer to the database discovery event.
 */
static void db_disc_handler(ble_db_discovery_evt_t * p_evt)
{
    ble_lbs_on_db_disc_evt(&m_ble_lbs_c, p_evt);
}


/**@brief Database discovery initialization.
 */
static void db_discovery_init(void)
{
    ret_code_t err_code = ble_db_discovery_init(db_disc_handler);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the log.
 */
static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


/**@brief Function for initializing the timer.
 */
static void timer_init(void)
{
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
	 err_code = app_timer_create(&m_battery_timer_id,
                                APP_TIMER_MODE_REPEATED,
                                battery_level_meas_timeout_handler);
    APP_ERROR_CHECK(err_code);

}


/**@brief Function for initializing the Power manager. */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


static void scan_init(void)
{
    ret_code_t          err_code;
    nrf_ble_scan_init_t init_scan;

    memset(&init_scan, 0, sizeof(init_scan));

    init_scan.connect_if_match = true;
    init_scan.conn_cfg_tag     = APP_BLE_CONN_CFG_TAG;

    err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
    APP_ERROR_CHECK(err_code);

    // Setting filters for scanning.
    err_code = nrf_ble_scan_filters_enable(&m_scan, NRF_BLE_SCAN_NAME_FILTER, false);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_NAME_FILTER, m_target_periph_name);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the GATT module.
 */
static void gatt_init(void)
{
    ret_code_t err_code = nrf_ble_gatt_init(&m_gatt, NULL);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop).
 *
 * @details Handle any pending log operation(s), then sleep until the next event occurs.
 */
static void idle_state_handle(void)
{
    NRF_LOG_FLUSH();
    nrf_pwr_mgmt_run();
}


int main(void)
{
    // Initialize.
    log_init();
    timer_init();
    leds_init();
   // buttons_init();
    power_management_init();
    ble_stack_init();
    scan_init();
    gatt_init();
    db_discovery_init();
    lbs_c_init();

    // Start execution.
    NRF_LOG_INFO("Blinky CENTRAL example started.");
    scan_start();

    // Turn on the LED to signal scanning.
    bsp_board_led_on(CENTRAL_SCANNING_LED);
	  application_timers_start();

    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
    }
}


uint32_t ble_nus_c_string_send(ble_lbs_c_t *  p_ble_lbs_c, uint8_t * p_string, uint16_t length)
{
    VERIFY_PARAM_NOT_NULL(p_ble_lbs_c);

    if (length > BLE_NUS_MAX_DATA_LEN)
    {
        NRF_LOG_WARNING("Content too long.");
        return NRF_ERROR_INVALID_PARAM;
    }
    if (p_ble_lbs_c->conn_handle == BLE_CONN_HANDLE_INVALID)
    {
        NRF_LOG_WARNING("Connection handle invalid.");
        return NRF_ERROR_INVALID_STATE;
    }

    ble_gattc_write_params_t const write_params =
    {
        .write_op = BLE_GATT_OP_WRITE_CMD,
        .flags    = BLE_GATT_EXEC_WRITE_FLAG_PREPARED_WRITE,
        .handle   = p_ble_lbs_c->peer_lbs_db.button_handle,
        .offset   = 0,
        .len      = length,
        .p_value  = p_string
    };
    NRF_LOG_INFO("sending\r\n");
    return sd_ble_gattc_write(p_ble_lbs_c->conn_handle, &write_params);
}

I am here by attaching the log of central which is sending the 8 bytes of data.

14:06:15.795: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:15.912: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:15.951: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:15.990: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.031: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.066: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending

14:06:16.102: 


<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.143: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.181: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.221: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.260: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.301: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.342: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.378: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.413: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.448: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.489: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.527: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.685: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.724: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.762: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.802: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.840: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.879: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.919: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.957: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



14:06:16.995: <info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending



<info> ble_lbs_c: sending

I  am here by attaching the log of data at peripheral side at every 10ms  to receive the data .

14:26:07.834: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][03][12][13][15][16][18][17][11][04][12][13][15][16][18][17][11][05]
Read: 0.

Read: 0.

14:26:07.859: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][06][12][13][15][16][18][17][11][07][12][13][15][16][18][17][11][08]
Read: 0.
14:26:07.887: 
Read: 0.


Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11]	[12][13][15][16][18][17][11]
[12][13][15][16][18][17][11][0B]
Read: 0.
14:26:07.915: 
Read: 0.

14:26:07.922: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
14:26:07.928: Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0C][12][13][15][16][18][17][11]
[12][13][15][16][18][17][11][0E]
Read: 0.

Read: 0.

14:26:07.949: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.
14:26:07.972: 
SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0F][12][13][15][16][18][17][11][10][12][13][15][16][18][17][11][11]
Read: 0.

Read: 0.

14:26:07.978: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.
14:26:07.999: 

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][12][12][13][15][16][18][17][11][13][12][13][15][16][18][17][11]
Read: 0.

Read: 0.


14:26:08.013: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
14:26:08.019: Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][01][12][13][15][16][18][17][11][02][12][13][15][16][18][17][11][03]
Read: 0.

Read: 0.


Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][04][12][13][15][16][18][17][11][05][12][13][15][16][18][17][11][06]
Read: 0.
14:26:08.065: 
Read: 0.

14:26:08.072: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][07][12][13][15][16][18][17][11][08][12][13][15][16][18][17][11]	
Read: 0.

Read: 0.

14:26:08.103: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11]
[12][13][15][16][18][17][11][0B][12][13][15][16][18][17][11][0C]
Read: 0.

Read: 0.

14:26:08.130: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11]
[12][13][15][16][18][17][11][0E][12][13][15][16][18][17][11][0F]
Read: 0.

Read: 0.

14:26:08.161: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][10][12][13][15][16][18][17][11][11][12][13][15][16][18][17][11][12]
Read: 0.

Read: 0.

14:26:08.188: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][13][12][13][15][16][18][17][11]
Read: 0.

Read: 0.

14:26:08.219: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][02][12][13][15][16][18][17][11][03][12][13][15][16][18][17][11][04]
Read: 0.

Read: 0.

14:26:08.247: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][05][12][13][15][16][18][17][11][06][12][13][15][16][18][17][11][07]
Read: 0.
14:26:08.277: 
Read: 0.


Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][08][12][13][15][16][18][17][11]	[12][13][15][16][18][17][11]

Read: 0.

Read: 0.

14:26:08.313: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0B][12][13][15][16][18][17][11][0C][12][13][15][16][18][17][11]

Read: 0.

Read: 0.

14:26:08.340: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0E][12][13][15][16][18][17][11][0F][12][13][15][16][18][17][11][10]
Read: 0.

Read: 0.


Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][11][12][13][15][16][18][17][11][12][12][13][15][16][18][17][11][13]
Read: 0.

Read: 0.

14:26:08.403: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
14:26:08.410: Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11]
Read: 0.

Read: 0.

14:26:08.431: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][03][12][13][15][16][18][17][11][04][12][13][15][16][18][17][11][05]
Read: 0.

Read: 0.

14:26:08.462: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][06][12][13][15][16][18][17][11][07][12][13][15][16][18][17][11][08]
Read: 0.

Read: 0.

14:26:08.490: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11]	[12][13][15][16][18][17][11]
[12][13][15][16][18][17][11][0B]
Read: 0.

Read: 0.

14:26:08.518: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0C][12][13][15][16][18][17][11]
[12][13][15][16][18][17][11][0E]
Read: 0.

Read: 0.

14:26:08.548: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.
14:26:08.571: 

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][0F][12][13][15][16][18][17][11][10][12][13][15][16][18][17][11][11]
Read: 0.

Read: 0.

14:26:08.580: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][12][12][13][15][16][18][17][11][13][12][13][15][16][18][17][11]
Read: 0.

Read: 0.

14:26:08.608: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][01][12][13][15][16][18][17][11][02][12][13][15][16][18][17][11][03]
Read: 0.

Read: 0.

14:26:08.638: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][04][12][13][15][16][18][17][11][05][12][13][15][16][18][17][11][06]
Read: 0.

Read: 0.

14:26:08.667: 
14:26:08.671: 
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>
Data Indication Event, Connection ID 1, Received 8 bytes.

SPP+LE>Read: 24.
data== [12][13][15][16][18][17][11][07][12][13][15][16][18][17][11][08][12][13][15][16][18][17][11]	
Read: 0.

Read: 0.

14:26:08.701: 
Data Indication Event, Connection ID 1, Received 8 bytes.

S

[Karl Ylvisaker]

Hello,

Sorry, it seems I misunderstood the roles in your initial post.

sharmelaraju said:

Thank you for the support.

No problem at all, I am happy to help!

sharmelaraju said:

Please check the code and let me know if there is any changes isrequired.

You code seems fine, I do not immediately see anything that needs reconfiguration here.

sharmelaraju said:

I am here by attaching the log of central which is sending the 8 bytes of data.

The timestamps in the log indicates that the data is sent at the correct time interval of 10 ms.

sharmelaraju said:

I  am here by attaching the log of data at peripheral side at every 10ms  to receive the data .

From the logs you have provided from the peripheral, it seems that the "Read" printout happens 3 times in a row, following 3 received transmissions of 8 bytes - indicating that the data is in fact received at the right time, but it is only processed every 30 ms.
Based on this, I suspect that your trouble is at the peripheral CC2564MODA device.
Could you ensure that the processing of the BLE received data happens at the expected time on the peripheral?

In conclusion, I would think that this is a problem at your peripheral unit.
From the peripheral-log side it seems that it receives the bytes at the appropriate time.
Could it be that your peripheral only handles the data once its buffer is full, or could it be that it is executing a higher-priority task for 20-30 ms at the time, making it unable to process the BLE data it received in the 20-30 ms window?

Best regards,
Karl