when I add uart to ble central multilink,there are all of "

[ckckckboy]

Hi all:

when i add uart code in ble_multilink ,and it gived me errors like this:

"<error> app: Fatal error
<warning> app: System reset
<error> app: Fatal error
<warning> app: System reset
<error> app: Fatal error
<warning> app: System reset
<error> app: Fatal error
<warning> app: System reset
<error> app: Fatal error
<warning> app: System reset
<error> app: Fatal error
<warning> app: System reset
<error> app: Fatal error
<warning> app: System reset
<error> app: Fatal error"

my work steps is:

First:I change NRF_SDH_BLE_CENTRAL_LINK_COUNT from 8 to 20,and it works fine ,i can link peripheral.

Second:I add ble_central_uart_c code in multilink project,and it compling ok,but when i download to my NRF52832 board,it can't connect to perpheral,and it throw me those errors.

can anyone help me?please,thank you 

[Vidar Berg]

Hi,

If you compile your project with DEBUG defined you will get the file name, line number, and error code of where the error occurred (error module). Please try re-compile your project with this flag set and check what the error code is and which function call it was returned from.   

[ckckckboy]

Thank you for your reply! when I run in debug mode,it can just goto app_error_weak,i also didn't know where my code is wrong,i'm a newbee,and i check my code,i also can't konw where is wrong,Could you send me a debug blog for NRF52 project,and This is my main code:

/**
* Copyright (c) 2014 - 2018, 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 example can be a central for up to 8 peripherals.
* The peripheral is called ble_app_blinky and can be found in the ble_peripheral
* folder.
*/

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "nordic_common.h"
#include "nrf_sdh.h"
#include "nrf_sdh_ble.h"
#include "app_timer.h"
//new added
#include "app_uart.h"
#include "app_util.h"
//end my added
#include "bsp_btn_ble.h"
#include "ble.h"
#include "ble_hci.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"
#include "ble_db_discovery.h"
#include "ble_lbs_c.h"
#include "ble_conn_state.h"
//my added
#include "ble_nus_c.h"
//end added
#include "nrf_ble_gatt.h"
#include "nrf_pwr_mgmt.h"

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

#define APP_BLE_CONN_CFG_TAG 1 /**< A tag that refers to the BLE stack configuration we set with @ref sd_ble_cfg_set. Default tag is @ref APP_BLE_CONN_CFG_TAG. */
#define APP_BLE_OBSERVER_PRIO 3 /**< Application's BLE observer priority. You shouldn't need to modify this value. */

//my added
#define UART_TX_BUF_SIZE 256 /**< UART TX buffer size. */
#define UART_RX_BUF_SIZE 256 /**< UART RX buffer size. */
#define NUS_SERVICE_UUID_TYPE BLE_UUID_TYPE_VENDOR_BEGIN /**< UUID type for the Nordic UART Service (vendor specific). */
//end added

#define CENTRAL_SCANNING_LED BSP_BOARD_LED_0
#define CENTRAL_CONNECTED_LED BSP_BOARD_LED_1
#define LEDBUTTON_LED BSP_BOARD_LED_2 /**< LED to indicate a change of state of the the Button characteristic on the peer. */

#define LEDBUTTON_BUTTON 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 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 /**< Duration of the scanning in units of 10 milliseconds. If set to 0x0000, scanning will continue until it is explicitly disabled. */

#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. */

//my added
#define ECHOBACK_BLE_UART_DATA 1 /**< Echo the UART data that is received over the Nordic UART Service back to the sender. */
BLE_NUS_C_DEF(m_ble_nus_c); /**< BLE NUS service client instance. */
//end added
NRF_BLE_GATT_DEF(m_gatt); /**< GATT module instance. */
BLE_LBS_C_ARRAY_DEF(m_lbs_c, NRF_SDH_BLE_CENTRAL_LINK_COUNT); /**< LED Button client instances. */
BLE_DB_DISCOVERY_ARRAY_DEF(m_db_disc, NRF_SDH_BLE_CENTRAL_LINK_COUNT); /**< Database discovery module instances. */

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

static uint8_t m_scan_buffer_data[BLE_GAP_SCAN_BUFFER_MIN]; /**< buffer where advertising reports will be stored by the SoftDevice. */
//my added
static uint16_t m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - OPCODE_LENGTH - HANDLE_LENGTH; /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
//end added
/**@brief Pointer to the buffer where advertising reports will be stored by the SoftDevice. */
static ble_data_t m_scan_buffer =
{
m_scan_buffer_data,
BLE_GAP_SCAN_BUFFER_MIN
};

/**@brief Scan parameters requested for scanning and connection. */
static ble_gap_scan_params_t const m_scan_params =
{
.active = 0,
.interval = SCAN_INTERVAL,
.window = SCAN_WINDOW,

.timeout = SCAN_DURATION,
.scan_phys = BLE_GAP_PHY_1MBPS,
.filter_policy = BLE_GAP_SCAN_FP_ACCEPT_ALL,

};

/**@brief Connection parameters requested for connection. */
static ble_gap_conn_params_t const m_connection_param =
{
(uint16_t)MIN_CONNECTION_INTERVAL,
(uint16_t)MAX_CONNECTION_INTERVAL,
(uint16_t)SLAVE_LATENCY,
(uint16_t)SUPERVISION_TIMEOUT
};

/**@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 ret;

(void) sd_ble_gap_scan_stop();

NRF_LOG_INFO("Start scanning for device name %s.", (uint32_t)m_target_periph_name);
ret = sd_ble_gap_scan_start(&m_scan_params, &m_scan_buffer);
APP_ERROR_CHECK(ret);
// Turn on the LED to signal scanning.
bsp_board_led_on(CENTRAL_SCANNING_LED);
}

/**@brief Handles events coming from the LED Button central module.
*
* @param[in] p_lbs_c The instance of LBS_C that triggered the event.
* @param[in] p_lbs_c_evt The LBS_C event.
*/
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;

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("Link 0x%x, Button state changed on peer to 0x%x",
p_lbs_c_evt->conn_handle,
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 the advertising report BLE event.
*
* @param[in] p_adv_report Advertising report from the SoftDevice.
*/
static void on_adv_report(ble_gap_evt_adv_report_t const * p_adv_report)
{
ret_code_t err_code;

if (ble_advdata_name_find(p_adv_report->data.p_data,
p_adv_report->data.len,
m_target_periph_name))
{
// Name is a match, initiate connection.
err_code = sd_ble_gap_connect(&p_adv_report->peer_addr,
&m_scan_params,
&m_connection_param,
APP_BLE_CONN_CFG_TAG);
NRF_LOG_INFO("Connection Start");
for(int i=0;i<33;i++){
NRF_LOG_INFO("Connection data i %d",p_adv_report->data.p_data[i]);
//NRF_LOG_INFO("Connection char i %s",p_adv_report->data.p_data[i]);
//NRF_LOG_INFO("Connection hex i %x",p_adv_report->data.p_data[i]);
}
NRF_LOG_INFO("Connection end");
NRF_LOG_INFO("Connection data %d,%d",p_adv_report->data.p_data,p_adv_report->data.len);
if (err_code != NRF_SUCCESS)
{
NRF_LOG_ERROR("Connection Request Failed, reason %d", err_code);
}
}
else
{
err_code = sd_ble_gap_scan_start(NULL, &m_scan_buffer);
APP_ERROR_CHECK(err_code);
}
}

/**@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, initiate DB
// discovery, update LEDs status and resume scanning if necessary.
case BLE_GAP_EVT_CONNECTED:
{
NRF_LOG_INFO("Connection 0x%x established, starting DB discovery.",
p_gap_evt->conn_handle);

APP_ERROR_CHECK_BOOL(p_gap_evt->conn_handle < NRF_SDH_BLE_CENTRAL_LINK_COUNT);
err_code = ble_nus_c_handles_assign(&m_ble_nus_c, p_ble_evt->evt.gap_evt.conn_handle, NULL);
APP_ERROR_CHECK(err_code);
err_code = ble_lbs_c_handles_assign(&m_lbs_c[p_gap_evt->conn_handle],
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],
p_gap_evt->conn_handle);
if (err_code != NRF_ERROR_BUSY)
{
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);
if (ble_conn_state_central_conn_count() == NRF_SDH_BLE_CENTRAL_LINK_COUNT)
{
bsp_board_led_off(CENTRAL_SCANNING_LED);
}
else
{
// Resume scanning.
bsp_board_led_on(CENTRAL_SCANNING_LED);
scan_start();
}
} break; // BLE_GAP_EVT_CONNECTED

// 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("LBS central link 0x%x disconnected (reason: 0x%x)",
p_gap_evt->conn_handle,
p_gap_evt->params.disconnected.reason);

if (ble_conn_state_central_conn_count() == 0)
{
err_code = app_button_disable();
APP_ERROR_CHECK(err_code);

// Turn off connection indication LED
bsp_board_led_off(CENTRAL_CONNECTED_LED);
}

// Start scanning
scan_start();

// Turn on LED for indicating scanning
bsp_board_led_on(CENTRAL_SCANNING_LED);

} break;

case BLE_GAP_EVT_ADV_REPORT:
on_adv_report(&p_gap_evt->params.adv_report);
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:
{
NRF_LOG_DEBUG("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 collector 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;

for (uint32_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
{
err_code = ble_lbs_c_init(&m_lbs_c[i], &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 writing to the LED characteristic of all connected clients.
*
* @details Based on if the button is pressed or released, this function writes a high or low
* LED status to the server.
*
* @param[in] button_action The button action (press/release).
* Determines if the LEDs of the servers will be ON or OFF.
*
* @return If successful NRF_SUCCESS is returned. Otherwise, the error code from @ref ble_lbs_led_status_send.
*/
static ret_code_t led_status_send_to_all(uint8_t button_action)
{
ret_code_t err_code;

for (uint32_t i = 0; i< NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
{
err_code = ble_lbs_led_status_send(&m_lbs_c[i], button_action);
if (err_code != NRF_SUCCESS &&
err_code != BLE_ERROR_INVALID_CONN_HANDLE &&
err_code != NRF_ERROR_INVALID_STATE)
{
return err_code;
}
}
return NRF_SUCCESS;
}

/**@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:
err_code = led_status_send_to_all(button_action);
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 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, 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)
{
NRF_LOG_DEBUG("call to ble_lbs_on_db_disc_evt for instance %d and link 0x%x!",
p_evt->conn_handle,
p_evt->conn_handle);

ble_lbs_on_db_disc_evt(&m_lbs_c[p_evt->conn_handle], p_evt);
}

//my added
/**@brief Function for handling characters received by the Nordic UART Service.
*
* @details This function takes a list of characters of length data_len and prints the characters out on UART.
* If @ref ECHOBACK_BLE_UART_DATA is set, the data is sent back to sender.
*/
static void ble_nus_chars_received_uart_print(uint8_t * p_data, uint16_t data_len)
{
ret_code_t ret_val;

NRF_LOG_DEBUG("Receiving data.");
NRF_LOG_HEXDUMP_DEBUG(p_data, data_len);

for (uint32_t i = 0; i < data_len; i++)
{
do
{
ret_val = app_uart_put(p_data[i]);
if ((ret_val != NRF_SUCCESS) && (ret_val != NRF_ERROR_BUSY))
{
NRF_LOG_ERROR("app_uart_put failed for index 0x%04x.", i);
APP_ERROR_CHECK(ret_val);
}
} while (ret_val == NRF_ERROR_BUSY);
}
if (p_data[data_len-1] == '\r')
{
while (app_uart_put('\n') == NRF_ERROR_BUSY);
}
if (ECHOBACK_BLE_UART_DATA)
{
// Send data back to peripheral.
do
{
ret_val = ble_nus_c_string_send(&m_ble_nus_c, p_data, data_len);
if ((ret_val != NRF_SUCCESS) && (ret_val != NRF_ERROR_BUSY))
{
NRF_LOG_ERROR("Failed sending NUS message. Error 0x%x. ", ret_val);
APP_ERROR_CHECK(ret_val);
}
} while (ret_val == NRF_ERROR_BUSY);
}
}

/**@brief Function for handling app_uart events.
*
* @details This function will receive a single character from the app_uart module and append it to
* a string. The string will be be sent over BLE when the last character received was a
* 'new line' '\n' (hex 0x0A) or if the string has reached the maximum data length.
*/
void uart_event_handle(app_uart_evt_t * p_event)
{
static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
static uint16_t index = 0;
uint32_t ret_val;

switch (p_event->evt_type)
{
/**@snippet [Handling data from UART] */
case APP_UART_DATA_READY:
UNUSED_VARIABLE(app_uart_get(&data_array[index]));
index++;

if ((data_array[index - 1] == '\n') || (index >= (m_ble_nus_max_data_len)))
{
NRF_LOG_DEBUG("Ready to send data over BLE NUS");
NRF_LOG_HEXDUMP_DEBUG(data_array, index);

do
{
ret_val = ble_nus_c_string_send(&m_ble_nus_c, data_array, index);
if ( (ret_val != NRF_ERROR_INVALID_STATE) && (ret_val != NRF_ERROR_BUSY) )
{
APP_ERROR_CHECK(ret_val);
}
} while (ret_val == NRF_ERROR_BUSY);

index = 0;
}
break;

/**@snippet [Handling data from UART] */
case APP_UART_COMMUNICATION_ERROR:
NRF_LOG_ERROR("Communication error occurred while handling UART.");
APP_ERROR_HANDLER(p_event->data.error_communication);
break;

case APP_UART_FIFO_ERROR:
NRF_LOG_ERROR("Error occurred in FIFO module used by UART.");
APP_ERROR_HANDLER(p_event->data.error_code);
break;

default:
break;
}
}

/**@brief Callback handling NUS Client events.
*
* @details This function is called to notify the application of NUS client events.
*
* @param[in] p_ble_nus_c NUS Client Handle. This identifies the NUS client
* @param[in] p_ble_nus_evt Pointer to the NUS Client event.
*/

/**@snippet [Handling events from the ble_nus_c module] */
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;
}
}
/**@snippet [Handling events from the ble_nus_c module] */
/**
* @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);
//end added
/** @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 power management.
*/
static void power_management_init(void)
{
ret_code_t err_code;
err_code = nrf_pwr_mgmt_init();
APP_ERROR_CHECK(err_code);
}

//my added
/**@brief Function for initializing the UART. */
static void uart_init(void)
{
ret_code_t err_code;

app_uart_comm_params_t const comm_params =
{
.rx_pin_no = RX_PIN_NUMBER,
.tx_pin_no = TX_PIN_NUMBER,
.rts_pin_no = RTS_PIN_NUMBER,
.cts_pin_no = CTS_PIN_NUMBER,
.flow_control = APP_UART_FLOW_CONTROL_DISABLED,
.use_parity = false,
.baud_rate = UART_BAUDRATE_BAUDRATE_Baud115200
};

APP_UART_FIFO_INIT(&comm_params,
UART_RX_BUF_SIZE,
UART_TX_BUF_SIZE,
uart_event_handle,
APP_IRQ_PRIORITY_LOWEST,
err_code);
printf("err_uart_code%s",err_code);
APP_ERROR_CHECK(err_code);
}

/**@brief Function for initializing the NUS Client. */
static void nus_c_init(void)
{
ret_code_t err_code;
ble_nus_c_init_t init;

init.evt_handler = ble_nus_c_evt_handler;

err_code = ble_nus_c_init(&m_ble_nus_c, &init);
APP_ERROR_CHECK(err_code);
}

//end added
/**@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)
{
if (NRF_LOG_PROCESS() == false)
{
nrf_pwr_mgmt_run();
}
}

/** @brief Function for initializing the 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 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, NULL);
APP_ERROR_CHECK(err_code);
}

int main(void)
{
// Initialize.
log_init();
timer_init();
//my added
uart_init();
//end added
leds_init();
buttons_init();
power_management_init();
ble_stack_init();
gatt_init();
//my added
nus_c_init();
//end added
db_discovery_init();
lbs_c_init();
ble_conn_state_init();
// Start execution.
NRF_LOG_INFO("Multilink example started.");
scan_start();

for (;;)
{
idle_state_handle();
}
}

[Vidar Berg]

Hi,

Which toolchain are you using, pure GCC, Segger embedded studio, Keil or IAR? Here is a relevant but a bit dated thread regarding debugging: https://devzone.nordicsemi.com/f/nordic-q-a/10729/my-device-is-freezing-and-restarting