NRF52840-DK interface to External BLE Pressure & temperature Sensor

[Vipul2988]

Hi All,

I am new and trying to connect External BLE Pressure Sensor to NRF52840-DK Board

Do you have any example code for interfacing external BLE sensors that I can refer ?

What you suggest to start with .?

[Einar Thorsrud]

Hi,

It is not clear to me if you want to communicate with a sensor device via BLE, or if you have a sensor connected to SPI/TWI or similar, and want to communicate sensor data via BLE. Please elaborate.

[Vipul2988]

Hello,

I want to read third party TDWLB (Transducer Direct LLC) Pressure device value in nRF52840 Board via BLE.

[Vipul2988]

Hi Einar,

Before using Nordic UART service Client, I am trying  to pair/connect other device as peripheral to nrf52840 Central.

But it looks like not paring with peripheral device, I looked into Ble_app_Blinky_C example.

Right now I am using nRF5_SDK_17.0.2 with pca10056/S140/SES having nRF52840-DK board

I have changed below things in Main.c

static char const p_target_periph_name[] = "34704" ;

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

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

init_cus_scan.connect_if_match = true;
init_cus_scan.conn_cfg_tag = APP_BLE_CONN_CFG_TAG;

err_code = nrf_ble_scan_init(&m_scan, &init_cus_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, p_target_periph_name);
APP_ERROR_CHECK(err_code);
}

Also Changed #define NRF_BLE_SCAN_NAME_CNT to 1 in sdk_config.h

from here pasted main.c

/**
* Copyright (c) 2014 - 2020, 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"

#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. */
NRF_BLE_GQ_DEF(m_ble_gatt_queue, /**< BLE GATT Queue instance. */
NRF_SDH_BLE_CENTRAL_LINK_COUNT,
NRF_BLE_GQ_QUEUE_SIZE);

//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 p_target_periph_name[] = "34704"; /**Vipul added new

/**@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 handling the LED Button Service client errors.
*
* @param[in] nrf_error Error code containing information about what went wrong.
*/
static void lbs_error_handler(uint32_t nrf_error)
{
APP_ERROR_HANDLER(nrf_error);
}

/**@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;
}
}

/**@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.");
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);

// 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_DEBUG("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_DEBUG("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_DEBUG("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_DEBUG("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;

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

/**@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;
lbs_c_init_obj.p_gatt_queue = &m_ble_gatt_queue;
lbs_c_init_obj.error_handler = lbs_error_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)
{
ble_db_discovery_init_t db_init;

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

db_init.evt_handler = db_disc_handler;
db_init.p_gatt_queue = &m_ble_gatt_queue;

ret_code_t err_code = ble_db_discovery_init(&db_init);
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);
}

/**@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;
nrf_ble_scan_init_t init_cus_scan;

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

init_cus_scan.connect_if_match = true;
init_cus_scan.conn_cfg_tag = APP_BLE_CONN_CFG_TAG;

err_code = nrf_ble_scan_init(&m_scan, &init_cus_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, p_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);

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

[Einar Thorsrud]

Hi,

Vipul2988 said:

But it looks like not paring with peripheral device, I looked into Ble_app_Blinky_C example.

There is no code for handling pairing in what you pasted. You should look at an example that use the peer manager in order to see how it is used, for instance the BLE Heart Rate Collector Example.

PS: Please insert code snippets using Insert- > Code in the future, as that is much more readable. And for full files (like your main.c) it is better to use Insert -> Image/Video/File.

[Vipul2988]

 

Hi Einar,

in Peer Manager, it will help after a BLE connection is established by the SoftDevice, the Peer Manager is responsible for the pairing procedure and, if requested, for creating a bond.

but how to establish BLE connection first ?
between nRF5840-DK and Other peripheral sensor 

[Einar Thorsrud]

In a nutshell, in order to connect the peripheral will advertise in connectable mode, and the central will scan for peripherals advertising something it filters on (typically UUID, name or BLE address). Then it connects. You can see how this is handled in some central examples, again I suggest you look at the BLE Heart Rate Collector Example. Using the SDK scan module you can do this quite easy in the central, so if you look at the referred example, you have this code snippet that configures the scan module to filter on the NUS UUID, and connect to the first device that matches the filter:

static void ble_nus_c_evt_handler(ble_nus_c_t * p_ble_nus_c, ble_nus_c_evt_t const * p_ble_nus_evt)
{
    ret_code_t err_code;

    switch (p_ble_nus_evt->evt_type)
    {
        case BLE_NUS_C_EVT_DISCOVERY_COMPLETE:
            NRF_LOG_INFO("Discovery complete.");
            err_code = ble_nus_c_handles_assign(p_ble_nus_c, p_ble_nus_evt->conn_handle, &p_ble_nus_evt->handles);
            APP_ERROR_CHECK(err_code);

            err_code = ble_nus_c_tx_notif_enable(p_ble_nus_c);
            APP_ERROR_CHECK(err_code);
            NRF_LOG_INFO("Connected to device with Nordic UART Service.");
            break;

        case BLE_NUS_C_EVT_NUS_TX_EVT:
            ble_nus_chars_received_uart_print(p_ble_nus_evt->p_data, p_ble_nus_evt->data_len);
            break;

        case BLE_NUS_C_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected.");
            scan_start();
            break;
    }
}

Actual scanning is then started with nrf_ble_scan_start().

[Vipul2988]

Hi Einar,

Thanks for your support. I am able to pair the sensor which is advertising using UUID --> 18FF in below image.

Now I want to access Attribute Table Data in which has some unknown characteristic with UUID has value which we want to use in our process.

  

[Einar Thorsrud]

I see. That is demonstrated by the various GATT service clients in the SDK as described in earlier posts. You should look at one of those implementations that fit and do the same, adapting it to your needs.

[Vipul2988]

Fullscreen ble_bas_c.c Download

/**
 * Copyright (c) 2012 - 2020, 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.
 *
 */
#include "sdk_common.h"
#if NRF_MODULE_ENABLED(BLE_BAS_C)
#include "ble_bas_c.h"
#include "ble_types.h"
#include "ble_db_discovery.h"
#include "ble_gattc.h"
#define NRF_LOG_MODULE_NAME ble_bas_c
#include "nrf_log.h"
NRF_LOG_MODULE_REGISTER();


/**@brief Function for intercepting errors of GATTC and BLE GATT Queue.
 *
 * @param[in] nrf_error   Error code.
 * @param[in] p_ctx       Parameter from the event handler.
 * @param[in] conn_handle Connection handle.
 */
static void gatt_error_handler(uint32_t   nrf_error,
                               void     * p_ctx,
                               uint16_t   conn_handle)
{
    ble_bas_c_t * p_bas_c = (ble_bas_c_t *)p_ctx;

    NRF_LOG_DEBUG("A GATT Client error has occurred on conn_handle: 0X%X", conn_handle);

    if (p_bas_c->error_handler != NULL)
    {
        p_bas_c->error_handler(nrf_error);
    }
}


/**@brief     Function for handling read response events.
 *
 * @details   This function validates the read response and raises the appropriate
 *            event to the application.
 *
 * @param[in] p_bas_c   Pointer to the Battery Service Client Structure.
 * @param[in] p_ble_evt Pointer to the SoftDevice event.
 */
static void on_read_rsp(ble_bas_c_t * p_bas_c, ble_evt_t const * p_ble_evt)
{
    const ble_gattc_evt_read_rsp_t * p_response;

    // Check if the event is on the link for this instance.
    if (p_bas_c->conn_handle != p_ble_evt->evt.gattc_evt.conn_handle)
    {
        return;
    }

    p_response = &p_ble_evt->evt.gattc_evt.params.read_rsp;

    if (p_response->handle == p_bas_c->peer_bas_db.bl_handle)
    {
        ble_bas_c_evt_t evt;

        evt.conn_handle = p_ble_evt->evt.gattc_evt.conn_handle;
        evt.evt_type = BLE_BAS_C_EVT_BATT_READ_RESP;

        evt.params.battery_level = p_response->data[0];

        p_bas_c->evt_handler(p_bas_c, &evt);
    }
}


/**@brief     Function for handling Handle Value Notification received from the SoftDevice.
 *
 * @details   This function handles the Handle Value Notification received from the SoftDevice
 *            and checks whether it is a notification of the Battery Level measurement from the peer. If
 *            it is, this function decodes the battery level measurement and sends it to the
 *            application.
 *
 * @param[in] p_ble_bas_c Pointer to the Battery Service Client structure.
 * @param[in] p_ble_evt   Pointer to the BLE event received.
 */
static void on_hvx(ble_bas_c_t * p_ble_bas_c, ble_evt_t const * p_ble_evt)
{
    // Check if the event is on the link for this instance.
    if (p_ble_bas_c->conn_handle != p_ble_evt->evt.gattc_evt.conn_handle)
    {
        return;
    }
    // Check if this notification is a battery level notification.
    if (p_ble_evt->evt.gattc_evt.params.hvx.handle == p_ble_bas_c->peer_bas_db.bl_handle)
    {
        if (p_ble_evt->evt.gattc_evt.params.hvx.len == 1)
        {
            ble_bas_c_evt_t ble_bas_c_evt;
            ble_bas_c_evt.conn_handle = p_ble_evt->evt.gattc_evt.conn_handle;
            ble_bas_c_evt.evt_type    = BLE_BAS_C_EVT_BATT_NOTIFICATION;

            ble_bas_c_evt.params.battery_level = p_ble_evt->evt.gattc_evt.params.hvx.data[0];

            p_ble_bas_c->evt_handler(p_ble_bas_c, &ble_bas_c_evt);
        }
    }
}


void ble_bas_on_db_disc_evt(ble_bas_c_t * p_ble_bas_c, const ble_db_discovery_evt_t * p_evt)
{
   // NRF_LOG_INFO("Entering into the ble_bas_on_db_disc_evt");

     // Check if the Battery Service was discovered.
    if (p_evt->evt_type == BLE_DB_DISCOVERY_COMPLETE
        &&
        p_evt->params.discovered_db.srv_uuid.uuid == BLE_UUID_BATTERY_SERVICE
        &&
        p_evt->params.discovered_db.srv_uuid.type == BLE_UUID_TYPE_BLE)
    {
        // Find the CCCD Handle of the Battery Level characteristic.
        uint8_t i;
        
        ble_bas_c_evt_t evt;
        evt.evt_type    = BLE_BAS_C_EVT_DISCOVERY_COMPLETE;
        evt.conn_handle = p_evt->conn_handle;
        for (i = 0; i < p_evt->params.discovered_db.char_count; i++)
        {
            if (p_evt->params.discovered_db.charateristics[i].characteristic.uuid.uuid ==
                BLE_UUID_BATTERY_LEVEL_CHAR)
            {
                // Found Battery Level characteristic. Store CCCD handle and break.
                evt.params.bas_db.bl_cccd_handle =
                    p_evt->params.discovered_db.charateristics[i].cccd_handle;
                evt.params.bas_db.bl_handle =
                    p_evt->params.discovered_db.charateristics[i].characteristic.handle_value;
                break;
            }
        }

        NRF_LOG_INFO("Battery Service discovered at peer.");

        //If the instance has been assigned prior to db_discovery, assign the db_handles.
        if (p_ble_bas_c->conn_handle != BLE_CONN_HANDLE_INVALID)
        {
            if ((p_ble_bas_c->peer_bas_db.bl_cccd_handle == BLE_GATT_HANDLE_INVALID)&&
                (p_ble_bas_c->peer_bas_db.bl_handle      == BLE_GATT_HANDLE_INVALID))
            {
                p_ble_bas_c->peer_bas_db = evt.params.bas_db;
                 
            }
        }
        p_ble_bas_c->evt_handler(p_ble_bas_c, &evt);
    }
    else if (p_evt->evt_type == BLE_DB_DISCOVERY_SRV_NOT_FOUND)
    {
        NRF_LOG_INFO("BLE_DB_DISCOVERY_SRV_NOT_FOUND");
        NRF_LOG_DEBUG("Battery Service discovery failure at peer. ");
    }
    else if (p_evt->evt_type == BLE_DB_DISCOVERY_ERROR)
    {
        NRF_LOG_INFO("BLE_DB_DISCOVERY_ERROR");
        NRF_LOG_DEBUG("Battery Service discovery failure at peer. ");
    }

    else if (p_evt->evt_type == BLE_DB_DISCOVERY_COMPLETE)
        {
          NRF_LOG_INFO("BLE_DB_DISCOVERY_COMPLETE");
        }
    else
    {
        // Do nothing.
    }
}


/**@brief Function for creating a message for writing to the CCCD.
 */
static uint32_t cccd_configure(ble_bas_c_t * p_ble_bas_c, bool notification_enable)
{
    NRF_LOG_DEBUG("Configuring CCCD. CCCD Handle = %d, Connection Handle = %d",
                  p_ble_bas_c->peer_bas_db.bl_cccd_handle,
                  p_ble_bas_c->conn_handle);

    nrf_ble_gq_req_t bas_c_req;
    uint8_t          cccd[BLE_CCCD_VALUE_LEN];
    uint16_t         cccd_val = notification_enable ? BLE_GATT_HVX_NOTIFICATION : 0;

    cccd[0] = LSB_16(cccd_val);
    cccd[1] = MSB_16(cccd_val);

    memset(&bas_c_req, 0, sizeof(bas_c_req));
 
    bas_c_req.type                        = NRF_BLE_GQ_REQ_GATTC_WRITE;
    bas_c_req.error_handler.cb            = gatt_error_handler;
    bas_c_req.error_handler.p_ctx         = p_ble_bas_c;
    bas_c_req.params.gattc_write.handle   = p_ble_bas_c->peer_bas_db.bl_cccd_handle;
    bas_c_req.params.gattc_write.len      = BLE_CCCD_VALUE_LEN;
    bas_c_req.params.gattc_write.p_value  = cccd;
    bas_c_req.params.gattc_write.offset   = 0;
    bas_c_req.params.gattc_write.write_op = BLE_GATT_OP_WRITE_REQ;

    return nrf_ble_gq_item_add(p_ble_bas_c->p_gatt_queue, &bas_c_req, p_ble_bas_c->conn_handle);
}


uint32_t ble_bas_c_init(ble_bas_c_t * p_ble_bas_c, ble_bas_c_init_t * p_ble_bas_c_init)
{
    VERIFY_PARAM_NOT_NULL(p_ble_bas_c);
    VERIFY_PARAM_NOT_NULL(p_ble_bas_c_init);

    ble_uuid_t bas_uuid;

    bas_uuid.type                = BLE_UUID_TYPE_BLE;
    bas_uuid.uuid                = BLE_UUID_BATTERY_SERVICE;

    p_ble_bas_c->conn_handle                = BLE_CONN_HANDLE_INVALID;
    p_ble_bas_c->peer_bas_db.bl_cccd_handle = BLE_GATT_HANDLE_INVALID;
    p_ble_bas_c->peer_bas_db.bl_handle      = BLE_GATT_HANDLE_INVALID;
    p_ble_bas_c->evt_handler                = p_ble_bas_c_init->evt_handler;
    p_ble_bas_c->error_handler              = p_ble_bas_c_init->error_handler;
    p_ble_bas_c->p_gatt_queue               = p_ble_bas_c_init->p_gatt_queue;

    return ble_db_discovery_evt_register(&bas_uuid);
}


/**@brief     Function for handling the Disconnected event received from the SoftDevice.
 *
 * @details   This function checks whether the disconnect event is happening on the link
 *            associated with the current instance of the module. If the event is happening,
 *            the function sets the instance's conn_handle to invalid.
 *
 * @param[in] p_ble_bas_c Pointer to the Battery Service Client structure.
 * @param[in] p_ble_evt   Pointer to the BLE event received.
 */
static void on_disconnected(ble_bas_c_t * p_ble_bas_c, const ble_evt_t * p_ble_evt)
{
    if (p_ble_bas_c->conn_handle == p_ble_evt->evt.gap_evt.conn_handle)
    {
        p_ble_bas_c->conn_handle                = BLE_CONN_HANDLE_INVALID;
        p_ble_bas_c->peer_bas_db.bl_cccd_handle = BLE_GATT_HANDLE_INVALID;
        p_ble_bas_c->peer_bas_db.bl_handle      = BLE_GATT_HANDLE_INVALID;
    }
}


void ble_bas_c_on_ble_evt(ble_evt_t const * p_ble_evt, void * p_context)
{
    if ((p_ble_evt == NULL) || (p_context == NULL))
    {
        return;
    }

    ble_bas_c_t * p_ble_bas_c = (ble_bas_c_t *)p_context;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GATTC_EVT_HVX:
            on_hvx(p_ble_bas_c, p_ble_evt);
            break;

        case BLE_GATTC_EVT_READ_RSP:
            on_read_rsp(p_ble_bas_c, p_ble_evt);
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            on_disconnected(p_ble_bas_c, p_ble_evt);
            break;

        default:
            break;
    }
}


uint32_t ble_bas_c_bl_notif_enable(ble_bas_c_t * p_ble_bas_c)
{
    VERIFY_PARAM_NOT_NULL(p_ble_bas_c);

    if (p_ble_bas_c->conn_handle == BLE_CONN_HANDLE_INVALID)
    {
        return NRF_ERROR_INVALID_STATE;
    }

    return cccd_configure(p_ble_bas_c, true);
}


uint32_t ble_bas_c_bl_read(ble_bas_c_t * p_ble_bas_c)
{
    VERIFY_PARAM_NOT_NULL(p_ble_bas_c);
    if (p_ble_bas_c->conn_handle == BLE_CONN_HANDLE_INVALID)
    {
        return NRF_ERROR_INVALID_STATE;
    }

    nrf_ble_gq_req_t bas_c_req;

    memset(&bas_c_req, 0, sizeof(bas_c_req));
    bas_c_req.type                     = NRF_BLE_GQ_REQ_GATTC_READ;
    bas_c_req.error_handler.cb         = gatt_error_handler;
    bas_c_req.error_handler.p_ctx      = p_ble_bas_c;
    bas_c_req.params.gattc_read.handle = p_ble_bas_c->peer_bas_db.bl_handle;

    return nrf_ble_gq_item_add(p_ble_bas_c->p_gatt_queue, &bas_c_req, p_ble_bas_c->conn_handle);
}


uint32_t ble_bas_c_handles_assign(ble_bas_c_t    * p_ble_bas_c,
                                  uint16_t         conn_handle,
                                  ble_bas_c_db_t * p_peer_handles)
{
    VERIFY_PARAM_NOT_NULL(p_ble_bas_c);

    p_ble_bas_c->conn_handle = conn_handle;
    if (p_peer_handles != NULL)
    {
        p_ble_bas_c->peer_bas_db = *p_peer_handles;
    }

    return nrf_ble_gq_conn_handle_register(p_ble_bas_c->p_gatt_queue, conn_handle);
}
#endif // NRF_MODULE_ENABLED(BLE_BAS_C)

Fullscreen 4428.main.c Download

/**
 * Copyright (c) 2014 - 2020, 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 Heart Rate Collector application main file.
 *
 * This file contains the source code for a sample heart rate collector.
 */

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "nordic_common.h"
#include "nrf_sdm.h"
#include "ble.h"
#include "ble_hci.h"
#include "ble_db_discovery.h"
#include "ble_srv_common.h"
#include "nrf_sdh.h"
#include "nrf_sdh_ble.h"
#include "nrf_sdh_soc.h"
#include "nrf_pwr_mgmt.h"
#include "app_util.h"
#include "app_error.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include "ble_hrs_c.h"
#include "ble_bas_c.h"
#include "app_util.h"
#include "app_timer.h"
#include "bsp_btn_ble.h"
#include "fds.h"
#include "nrf_fstorage.h"
#include "ble_conn_state.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_lesc.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "nrf_ble_scan.h"


#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. */
#define APP_SOC_OBSERVER_PRIO       1                                   /**< Applications' SoC observer priority. You shouldn't need to modify this value. */

#define LESC_DEBUG_MODE             0                                   /**< Set to 1 to use LESC debug keys, allows you to use a sniffer to inspect traffic. */

#define SEC_PARAM_BOND              1                                   /**< Perform bonding. */
#define SEC_PARAM_MITM              0                                   /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC              1                                   /**< LE Secure Connections enabled. */
#define SEC_PARAM_KEYPRESS          0                                   /**< Keypress notifications not enabled. */
#define SEC_PARAM_IO_CAPABILITIES   BLE_GAP_IO_CAPS_NONE                /**< No I/O capabilities. */
#define SEC_PARAM_OOB               0                                   /**< Out Of Band data not available. */
#define SEC_PARAM_MIN_KEY_SIZE      7                                   /**< Minimum encryption key size in octets. */
#define SEC_PARAM_MAX_KEY_SIZE      16                                  /**< Maximum encryption key size in octets. */

#define SCAN_DURATION_WITELIST      3000                                /**< Duration of the scanning in units of 10 milliseconds. */

#define TARGET_UUID                 BLE_UUID_HEART_RATE_SERVICE         /**< Target device uuid that application is looking for. */

/**@brief Macro to unpack 16bit unsigned UUID from octet stream. */
#define UUID16_EXTRACT(DST, SRC) \
    do                           \
    {                            \
        (*(DST))   = (SRC)[1];   \
        (*(DST)) <<= 8;          \
        (*(DST))  |= (SRC)[0];   \
    } while (0)


NRF_BLE_GQ_DEF(m_ble_gatt_queue,                                    /**< BLE GATT Queue instance. */
               NRF_SDH_BLE_CENTRAL_LINK_COUNT,
               NRF_BLE_GQ_QUEUE_SIZE);
BLE_HRS_C_DEF(m_hrs_c);                                             /**< Structure used to identify the heart rate client module. */
BLE_BAS_C_DEF(m_bas_c);                                             /**< Structure used to identify the Battery Service client module. */
NRF_BLE_GATT_DEF(m_gatt);                                           /**< GATT module instance. */
BLE_DB_DISCOVERY_DEF(m_db_disc);                                    /**< DB discovery module instance. */
NRF_BLE_SCAN_DEF(m_scan);                                           /**< Scanning module instance. */

static uint16_t m_conn_handle;                                      /**< Current connection handle. */
static bool     m_whitelist_disabled;                               /**< True if whitelist has been temporarily disabled. */
static bool     m_memory_access_in_progress;                        /**< Flag to keep track of ongoing operations on persistent memory. */

/**< Scan parameters requested for scanning and connection. */
static ble_gap_scan_params_t const m_scan_param =
{
    .active        = 0x01,
#if (NRF_SD_BLE_API_VERSION > 7)
    .interval_us   = NRF_BLE_SCAN_SCAN_INTERVAL * UNIT_0_625_MS,
    .window_us     = NRF_BLE_SCAN_SCAN_WINDOW * UNIT_0_625_MS,
#else
    .interval      = NRF_BLE_SCAN_SCAN_INTERVAL,
    .window        = NRF_BLE_SCAN_SCAN_WINDOW,
#endif // (NRF_SD_BLE_API_VERSION > 7)
    .filter_policy = BLE_GAP_SCAN_FP_WHITELIST,
    .timeout       = SCAN_DURATION_WITELIST,
    .scan_phys     = BLE_GAP_PHY_1MBPS,
};


/**@brief Names which the central applications will scan for, and which will be advertised by the peripherals.
 *  if these are set to empty strings, the UUIDs defined below will be used
 */
static char const m_target_periph_name[] = "";      /**< If you want to connect to a peripheral using a given advertising name, type its name here. */
static bool is_connect_per_addr = false;            /**< If you want to connect to a peripheral with a given address, set this to true and put the correct address in the variable below. */

static ble_gap_addr_t const m_target_periph_addr =
{
    /* Possible values for addr_type:
       BLE_GAP_ADDR_TYPE_PUBLIC,
       BLE_GAP_ADDR_TYPE_RANDOM_STATIC,
       BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_RESOLVABLE,
       BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_NON_RESOLVABLE. */
    .addr_type = BLE_GAP_ADDR_TYPE_RANDOM_STATIC,
    .addr      = {0x8D, 0xFE, 0x23, 0x86, 0x77, 0xD9}
};


static void scan_start(void);


/**@brief Function for 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 handling the Heart Rate Service Client and Battery Service Client errors.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void service_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@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_hrs_on_db_disc_evt(&m_hrs_c, p_evt);
    ble_bas_on_db_disc_evt(&m_bas_c, p_evt);
}


/**@brief Function for handling Peer Manager events.
 *
 * @param[in] p_evt  Peer Manager event.
 */
static void pm_evt_handler(pm_evt_t const * p_evt)
{
    pm_handler_on_pm_evt(p_evt);
    pm_handler_flash_clean(p_evt);

    switch (p_evt->evt_id)
    {
        case PM_EVT_PEERS_DELETE_SUCCEEDED:
            // Bonds are deleted. Start scanning.
            scan_start();
            break;

        default:
            break;
    }
}


/**
 * @brief Function for shutdown events.
 *
 * @param[in]   event       Shutdown type.
 */
static bool shutdown_handler(nrf_pwr_mgmt_evt_t event)
{
    ret_code_t err_code;

    err_code = bsp_indication_set(BSP_INDICATE_IDLE);
    APP_ERROR_CHECK(err_code);

    switch (event)
    {
        case NRF_PWR_MGMT_EVT_PREPARE_WAKEUP:
            // Prepare wakeup buttons.
            err_code = bsp_btn_ble_sleep_mode_prepare();
            APP_ERROR_CHECK(err_code);
            break;
        default:
            break;
    }

    return true;
}

NRF_PWR_MGMT_HANDLER_REGISTER(shutdown_handler, APP_SHUTDOWN_HANDLER_PRIORITY);


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

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
        {
            NRF_LOG_INFO("Nordic_HRM Peripheral is Connected.");

            // Discover peer's services.
            err_code = ble_db_discovery_start(&m_db_disc, p_ble_evt->evt.gap_evt.conn_handle);
            APP_ERROR_CHECK(err_code);

            err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
            APP_ERROR_CHECK(err_code);

            if (ble_conn_state_central_conn_count() < NRF_SDH_BLE_CENTRAL_LINK_COUNT)
            {
                scan_start();
            }
        } break;

        case BLE_GAP_EVT_DISCONNECTED:
        {
            NRF_LOG_INFO("Disconnected, reason 0x%x.",
                         p_gap_evt->params.disconnected.reason);

            err_code = bsp_indication_set(BSP_INDICATE_IDLE);
            APP_ERROR_CHECK(err_code);

            if (ble_conn_state_central_conn_count() < NRF_SDH_BLE_CENTRAL_LINK_COUNT)
            {
                scan_start();
            }
        } break;

        case BLE_GAP_EVT_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:
            // Accepting 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_DEBUG("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_DEBUG("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_DEBUG("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_GAP_EVT_SEC_PARAMS_REQUEST:
            NRF_LOG_DEBUG("BLE_GAP_EVT_SEC_PARAMS_REQUEST");
            break;

        case BLE_GAP_EVT_AUTH_KEY_REQUEST:
            NRF_LOG_INFO("BLE_GAP_EVT_AUTH_KEY_REQUEST");
            break;

        case BLE_GAP_EVT_LESC_DHKEY_REQUEST:
            NRF_LOG_INFO("BLE_GAP_EVT_LESC_DHKEY_REQUEST");
            break;

         case BLE_GAP_EVT_AUTH_STATUS:
             NRF_LOG_INFO("BLE_GAP_EVT_AUTH_STATUS: status=0x%x bond=0x%x lv4: %d kdist_own:0x%x kdist_peer:0x%x",
                          p_ble_evt->evt.gap_evt.params.auth_status.auth_status,
                          p_ble_evt->evt.gap_evt.params.auth_status.bonded,
                          p_ble_evt->evt.gap_evt.params.auth_status.sm1_levels.lv4,
                          *((uint8_t *)&p_ble_evt->evt.gap_evt.params.auth_status.kdist_own),
                          *((uint8_t *)&p_ble_evt->evt.gap_evt.params.auth_status.kdist_peer));
            break;

        default:
            break;
    }
}


/**@brief SoftDevice SoC event handler.
 *
 * @param[in]   evt_id      SoC event.
 * @param[in]   p_context   Context.
 */
static void soc_evt_handler(uint32_t evt_id, void * p_context)
{
    switch (evt_id)
    {
        case NRF_EVT_FLASH_OPERATION_SUCCESS:
            /* fall through */
        case NRF_EVT_FLASH_OPERATION_ERROR:

            if (m_memory_access_in_progress)
            {
                m_memory_access_in_progress = false;
                scan_start();
            }
            break;

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


/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupt.
 */
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 handlers for BLE and SoC events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
    NRF_SDH_SOC_OBSERVER(m_soc_observer, APP_SOC_OBSERVER_PRIO, soc_evt_handler, NULL);
}



/**@brief Function for the Peer Manager initialization.
 */
static void peer_manager_init(void)
{
    ble_gap_sec_params_t sec_param;
    ret_code_t err_code;

    err_code = pm_init();
    APP_ERROR_CHECK(err_code);

    memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));

    // Security parameters to be used for all security procedures.
    sec_param.bond           = SEC_PARAM_BOND;
    sec_param.mitm           = SEC_PARAM_MITM;
    sec_param.lesc           = SEC_PARAM_LESC;
    sec_param.keypress       = SEC_PARAM_KEYPRESS;
    sec_param.io_caps        = SEC_PARAM_IO_CAPABILITIES;
    sec_param.oob            = SEC_PARAM_OOB;
    sec_param.min_key_size   = SEC_PARAM_MIN_KEY_SIZE;
    sec_param.max_key_size   = SEC_PARAM_MAX_KEY_SIZE;
    sec_param.kdist_own.enc  = 1;
    sec_param.kdist_own.id   = 1;
    sec_param.kdist_peer.enc = 1;
    sec_param.kdist_peer.id  = 1;

    err_code = pm_sec_params_set(&sec_param);
    APP_ERROR_CHECK(err_code);

    err_code = pm_register(pm_evt_handler);
    APP_ERROR_CHECK(err_code);
}


/** @brief Clear bonding information from persistent storage
 */
static void delete_bonds(void)
{
    ret_code_t err_code;

    NRF_LOG_INFO("Erase bonds!");

    err_code = pm_peers_delete();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for disabling the use of whitelist for scanning.
 */
static void whitelist_disable(void)
{
    if (!m_whitelist_disabled)
    {
        NRF_LOG_INFO("Whitelist temporarily disabled.");
        m_whitelist_disabled = true;
        nrf_ble_scan_stop();
        scan_start();
    }
}


/**@brief Function for handling events from the BSP module.
 *
 * @param[in]   event   Event generated by button press.
 */
void bsp_event_handler(bsp_event_t event)
{
    ret_code_t err_code;

    switch (event)
    {
        case BSP_EVENT_SLEEP:
            nrf_pwr_mgmt_shutdown(NRF_PWR_MGMT_SHUTDOWN_GOTO_SYSOFF);
            break;

        case BSP_EVENT_DISCONNECT:
            err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            if (err_code != NRF_ERROR_INVALID_STATE)
            {
                APP_ERROR_CHECK(err_code);
            }
            break;

        case BSP_EVENT_WHITELIST_OFF:
            whitelist_disable();
            break;

        default:
            break;
    }
}


/**@brief Heart Rate Collector Handler.
 */
static void hrs_c_evt_handler(ble_hrs_c_t * p_hrs_c, ble_hrs_c_evt_t * p_hrs_c_evt)
{
    ret_code_t err_code;

    switch (p_hrs_c_evt->evt_type)
    {
        case BLE_HRS_C_EVT_DISCOVERY_COMPLETE:
        {
            NRF_LOG_DEBUG("Heart rate service discovered.");
            NRF_LOG_INFO("Heart rate service discovered.");
            err_code = ble_hrs_c_handles_assign(p_hrs_c,
                                                p_hrs_c_evt->conn_handle,
                                                &p_hrs_c_evt->params.peer_db);
            APP_ERROR_CHECK(err_code);

            // Initiate bonding.
            err_code = pm_conn_secure(p_hrs_c_evt->conn_handle, false);
            if (err_code != NRF_ERROR_BUSY)
            {
                APP_ERROR_CHECK(err_code);
            }

            // Heart rate service discovered. Enable notification of Heart Rate Measurement.
            err_code = ble_hrs_c_hrm_notif_enable(p_hrs_c);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_HRS_C_EVT_HRM_NOTIFICATION:
        {
            NRF_LOG_INFO("Heart Rate = %d.", p_hrs_c_evt->params.hrm.hr_value);

            if (p_hrs_c_evt->params.hrm.rr_intervals_cnt != 0)
            {
                uint32_t rr_avg = 0;
                for (uint32_t i = 0; i < p_hrs_c_evt->params.hrm.rr_intervals_cnt; i++)
                {
                    rr_avg += p_hrs_c_evt->params.hrm.rr_intervals[i];
                }
                rr_avg = rr_avg / p_hrs_c_evt->params.hrm.rr_intervals_cnt;
                NRF_LOG_DEBUG("rr_interval (avg) = %d.", rr_avg);
            }
        } break;

        default:
            break;
    }
}


/**@brief Battery level Collector Handler.
 */
static void bas_c_evt_handler(ble_bas_c_t * p_bas_c, ble_bas_c_evt_t * p_bas_c_evt)
{
    ret_code_t err_code;

    switch (p_bas_c_evt->evt_type)
    {
        case BLE_BAS_C_EVT_DISCOVERY_COMPLETE:
        {
            err_code = ble_bas_c_handles_assign(p_bas_c,
                                                p_bas_c_evt->conn_handle,
                                                &p_bas_c_evt->params.bas_db);
            APP_ERROR_CHECK(err_code);

            // Battery service discovered. Enable notification of Battery Level.
            NRF_LOG_DEBUG("Battery Service discovered. Reading battery level.");
            NRF_LOG_INFO("Battery Service discovered. Reading battery level.");

            err_code = ble_bas_c_bl_read(p_bas_c);
            APP_ERROR_CHECK(err_code);

            NRF_LOG_DEBUG("Enabling Battery Level Notification.");
            err_code = ble_bas_c_bl_notif_enable(p_bas_c);
            APP_ERROR_CHECK(err_code);

        } break;

        case BLE_BAS_C_EVT_BATT_NOTIFICATION:
            NRF_LOG_INFO("Battery Level received %d %%.", p_bas_c_evt->params.battery_level);
            break;

        case BLE_BAS_C_EVT_BATT_READ_RESP:
            NRF_LOG_INFO("Battery Level Read as %d %%.", p_bas_c_evt->params.battery_level);
            break;

        default:
            break;
    }
}


/**
 * @brief Heart rate collector initialization.
 */
static void hrs_c_init(void)
{
    ble_hrs_c_init_t hrs_c_init_obj;

    hrs_c_init_obj.evt_handler   = hrs_c_evt_handler;
    hrs_c_init_obj.error_handler = service_error_handler;
    hrs_c_init_obj.p_gatt_queue  = &m_ble_gatt_queue;

    ret_code_t err_code = ble_hrs_c_init(&m_hrs_c, &hrs_c_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**
 * @brief Battery level collector initialization.
 */
static void bas_c_init(void)
{
    ble_bas_c_init_t bas_c_init_obj;

    bas_c_init_obj.evt_handler   = bas_c_evt_handler;
    bas_c_init_obj.error_handler = service_error_handler;
    bas_c_init_obj.p_gatt_queue  = &m_ble_gatt_queue;

    ret_code_t err_code = ble_bas_c_init(&m_bas_c, &bas_c_init_obj);
    APP_ERROR_CHECK(err_code);
}


/**
 * @brief Database discovery collector initialization.
 */
static void db_discovery_init(void)
{
    ble_db_discovery_init_t db_init;

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

    db_init.evt_handler  = db_disc_handler;
    db_init.p_gatt_queue = &m_ble_gatt_queue;

    ret_code_t err_code = ble_db_discovery_init(&db_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Retrieve a list of peer manager peer IDs.
 *
 * @param[inout] p_peers   The buffer where to store the list of peer IDs.
 * @param[inout] p_size    In: The size of the @p p_peers buffer.
 *                         Out: The number of peers copied in the buffer.
 */
static void peer_list_get(pm_peer_id_t * p_peers, uint32_t * p_size)
{
    pm_peer_id_t peer_id;
    uint32_t     peers_to_copy;

    peers_to_copy = (*p_size < BLE_GAP_WHITELIST_ADDR_MAX_COUNT) ?
                     *p_size : BLE_GAP_WHITELIST_ADDR_MAX_COUNT;

    peer_id = pm_next_peer_id_get(PM_PEER_ID_INVALID);
    *p_size = 0;

    while ((peer_id != PM_PEER_ID_INVALID) && (peers_to_copy--))
    {
        p_peers[(*p_size)++] = peer_id;
        peer_id = pm_next_peer_id_get(peer_id);
    }
}


static void whitelist_load()
{
    ret_code_t   ret;
    pm_peer_id_t peers[8];
    uint32_t     peer_cnt;

    memset(peers, PM_PEER_ID_INVALID, sizeof(peers));
    peer_cnt = (sizeof(peers) / sizeof(pm_peer_id_t));

    // Load all peers from flash and whitelist them.
    peer_list_get(peers, &peer_cnt);

    ret = pm_whitelist_set(peers, peer_cnt);
    APP_ERROR_CHECK(ret);

    // Setup the device identies list.
    // Some SoftDevices do not support this feature.
    ret = pm_device_identities_list_set(peers, peer_cnt);
    if (ret != NRF_ERROR_NOT_SUPPORTED)
    {
        APP_ERROR_CHECK(ret);
    }
}


static void on_whitelist_req(void)
{
    ret_code_t err_code;

    // Whitelist buffers.
    ble_gap_addr_t whitelist_addrs[8];
    ble_gap_irk_t  whitelist_irks[8];

    memset(whitelist_addrs, 0x00, sizeof(whitelist_addrs));
    memset(whitelist_irks,  0x00, sizeof(whitelist_irks));

    uint32_t addr_cnt = (sizeof(whitelist_addrs) / sizeof(ble_gap_addr_t));
    uint32_t irk_cnt  = (sizeof(whitelist_irks)  / sizeof(ble_gap_irk_t));

    // Reload the whitelist and whitelist all peers.
    whitelist_load();

    // Get the whitelist previously set using pm_whitelist_set().
    err_code = pm_whitelist_get(whitelist_addrs, &addr_cnt,
                                whitelist_irks,  &irk_cnt);

    if (((addr_cnt == 0) && (irk_cnt == 0)) ||
        (m_whitelist_disabled))
    {
        // Don't use whitelist.
        err_code = nrf_ble_scan_params_set(&m_scan, NULL);
        APP_ERROR_CHECK(err_code);
    }
}


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

    if (nrf_fstorage_is_busy(NULL))
    {
        m_memory_access_in_progress = true;
        return;
    }

    NRF_LOG_INFO("Start Scannig for Nordic_HRM Peripheral");

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

    err_code = bsp_indication_set(BSP_INDICATE_SCANNING);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing buttons and leds.
 *
 * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
 */
static void buttons_leds_init(bool * p_erase_bonds)
{
    ret_code_t  err_code;
    bsp_event_t startup_event;

    err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
    APP_ERROR_CHECK(err_code);

    err_code = bsp_btn_ble_init(NULL, &startup_event);
    APP_ERROR_CHECK(err_code);

    *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}


/**@brief Function for initializing the nrf log module.
 */
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 power management module. */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief GATT module event handler.
 */
static void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
{
    switch (p_evt->evt_id)
    {
        case NRF_BLE_GATT_EVT_ATT_MTU_UPDATED:
        {
            NRF_LOG_INFO("GATT ATT MTU on connection 0x%x changed to %d.",
                         p_evt->conn_handle,
                         p_evt->params.att_mtu_effective);
        } break;

        case NRF_BLE_GATT_EVT_DATA_LENGTH_UPDATED:
        {
            NRF_LOG_INFO("Data length for connection 0x%x updated to %d.",
                         p_evt->conn_handle,
                         p_evt->params.data_length);
        } break;

        default:
            break;
    }
}


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_WHITELIST_REQUEST:
        {
            on_whitelist_req();
            m_whitelist_disabled = false;
        } break;

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

        case NRF_BLE_SCAN_EVT_SCAN_TIMEOUT:
        {
            NRF_LOG_INFO("Scan timed out.");
            scan_start();
        } break;

        case NRF_BLE_SCAN_EVT_FILTER_MATCH:
            break;
        case NRF_BLE_SCAN_EVT_WHITELIST_ADV_REPORT:
            break;

        default:
          break;
    }
}


/**@brief Function for initializing the timer.
 */
static void timer_init(void)
{
    ret_code_t err_code = app_timer_init();
    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, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initialization scanning and setting filters.
 */
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.p_scan_param     = &m_scan_param;
    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);

    ble_uuid_t uuid =
    {
        .uuid = TARGET_UUID,
        .type = BLE_UUID_TYPE_BLE,
    };

    err_code = nrf_ble_scan_filter_set(&m_scan,
                                       SCAN_UUID_FILTER,
                                       &uuid);
    APP_ERROR_CHECK(err_code);

    if (strlen(m_target_periph_name) != 0)
    {
        err_code = nrf_ble_scan_filter_set(&m_scan,
                                           SCAN_NAME_FILTER,
                                           m_target_periph_name);
        APP_ERROR_CHECK(err_code);
    }

    if (is_connect_per_addr)
    {
       err_code = nrf_ble_scan_filter_set(&m_scan,
                                          SCAN_ADDR_FILTER,
                                          m_target_periph_addr.addr);
       APP_ERROR_CHECK(err_code);
    }

    err_code = nrf_ble_scan_filters_enable(&m_scan,
                                           NRF_BLE_SCAN_ALL_FILTER,
                                           false);
    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)
{
    ret_code_t err_code;
    
    err_code = nrf_ble_lesc_request_handler();
    APP_ERROR_CHECK(err_code);
    
    NRF_LOG_FLUSH();
    nrf_pwr_mgmt_run();
}


/**@brief Function for starting a scan, or instead trigger it from peer manager (after
 *        deleting bonds).
 *
 * @param[in] p_erase_bonds Pointer to a bool to determine if bonds will be deleted before scanning.
 */
void scanning_start(bool * p_erase_bonds)
{
    // Start scanning for peripherals and initiate connection
    // with devices that advertise GATT Service UUID.
    if (*p_erase_bonds == true)
    {
        // Scan is started by the PM_EVT_PEERS_DELETE_SUCCEEDED event.
        delete_bonds();
    }
    else
    {
        scan_start();
    }
}


int main(void)
{
    bool erase_bonds;

    // Initialize.
    log_init();
    timer_init();
    power_management_init();
    buttons_leds_init(&erase_bonds);
    ble_stack_init();
    gatt_init();
    peer_manager_init();
    db_discovery_init();
    hrs_c_init();
    bas_c_init();
    scan_init();

    // Start execution.
    NRF_LOG_INFO("Programming Execution Started");
    scanning_start(&erase_bonds);

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

Hi Einar, 

As per your guidance I was trying to use Battery Service from Above said GATT Service. but could not able to read.

I have used one nRF52840-DK board with ble Peripheral --> ble_app_hrs  example

and second nRF52840-DK board with ble Central--> ble_app_hrs_c example.

I am trying to read battery level of Peripheral device in to the central ble_app_hrs_c example. 

but with using nRF log info I can see that my BLE_DB_DISCOVERY_ERROR instead of Discovery complete. See Image.

What you suggest here to make it happen ?

I have attached both main.c and ble_bas_c.c

[Einar Thorsrud]

Hi,

What you have here is basically the BLE Heart Rate Collector Example with some minor changes to logging that does not change the behavior. When I test your modifications against a DK with an unmodified Heart Rate Application it works as expected, so I suspect you did some changes there that broke it.

[Vipul2988]

So you mean are you able to connect BLE_DB_DISCOVERY_COMPLETE at your end ? and read the battery Level ?

[Einar Thorsrud]

Yes