Using ble_template example to transfer data

[noob_with_ucontrollers]

I am using nrf52832, SDK 15.2, Softdevice 6.1, Embedded Studio to program a custom PCB device. My aim is to eventually send data I have from a peripheral device (through SPI) via ble to any mobile app. As of now, for starters, I am trying the send the nrf_gpio_pin_read () data or just random values/strings. I started with the BLE_TEMPLATE example. 

The ble_template example runs (i.e it advertises) on my PCB custom device when I flash it. But when I edit it to incorporate the nus service to send data using nus_data_send() function, the device does not advertise anymore. My code builds and flashes just fine, but there is no data coming from it and it's stops advertising, I am not sure why (I didn't edit the ble_template example much just added a couple NUS things  here and there and add a data_send() function of my own)  

1. I don't get what I am doing wrong in my use of NUS functions that it stops advertising and doesn't send the sample string the way it's supposed to?

2. Is there another way I could go about to transfer a simple string/ int array wirelessly? Without using the NUS service or ble_data_send() function.

I do not use the nus_data_handler() or initialize it in the code because according to my understanding the handler is for data send TO the nrf via ble. 

/**
 * 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.
 *
 */
/** @file
 *
 * @defgroup ble_sdk_app_template_main main.c
 * @{
 * @ingroup ble_sdk_app_template
 * @brief Template project main file.
 *
 * This file contains a template for creating a new application. It has the code necessary to wakeup
 * from button, advertise, get a connection restart advertising on disconnect and if no new
 * connection created go back to system-off mode.
 * It can easily be used as a starting point for creating a new application, the comments identified
 * with 'YOUR_JOB' indicates where and how you can customize.
 */

#include <stdbool.h>
#include <stdint.h>
#include <string.h>

#include "nordic_common.h"
#include "nrf.h"
#include "app_error.h"
#include "ble.h"
#include "ble_hci.h"
#include "ble_srv_common.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"
#include "nrf_sdh.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdh_ble.h"
#include "app_timer.h"
#include "ble_nus.h"  //editted
#include "fds.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include "bsp_btn_ble.h"
#include "sensorsim.h"
#include "ble_conn_state.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_qwr.h"
#include "nrf_pwr_mgmt.h"
#include "nrf_delay.h"

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


#define DEVICE_NAME                     "Nordic_Template"                       /**< Name of device. Will be included in the advertising data. */
//editted below line
#define NUS_SERVICE_UUID_TYPE           BLE_UUID_TYPE_VENDOR_BEGIN                  /**< UUID type for the Nordic UART Service (vendor specific). */ //edited
#define MANUFACTURER_NAME               "NordicSemiconductor"                   /**< Manufacturer. Will be passed to Device Information Service. */
#define APP_ADV_INTERVAL                300                                     /**< The advertising interval (in units of 0.625 ms. This value corresponds to 187.5 ms). */

#define APP_ADV_DURATION                18000                                   /**< The advertising duration (180 seconds) in units of 10 milliseconds. */
#define APP_BLE_OBSERVER_PRIO           3                                       /**< Application's BLE observer priority. You shouldn't need to modify this value. */
#define APP_BLE_CONN_CFG_TAG            1                                       /**< A tag identifying the SoftDevice BLE configuration. */

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(100, UNIT_1_25_MS)        /**< Minimum acceptable connection interval (0.1 seconds). */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(200, UNIT_1_25_MS)        /**< Maximum acceptable connection interval (0.2 second). */
#define SLAVE_LATENCY                   0                                       /**< Slave latency. */
#define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)         /**< Connection supervisory timeout (4 seconds). */

#define FIRST_CONN_PARAMS_UPDATE_DELAY  APP_TIMER_TICKS(5000)                   /**< Time from initiating event (connect or start of notification) to first time sd_ble_gap_conn_param_update is called (5 seconds). */
#define NEXT_CONN_PARAMS_UPDATE_DELAY   APP_TIMER_TICKS(30000)                  /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT    3                                       /**< Number of attempts before giving up the connection parameter negotiation. */

#define SEC_PARAM_BOND                  1                                       /**< Perform bonding. */
#define SEC_PARAM_MITM                  0                                       /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC                  0                                       /**< LE Secure Connections not 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. */
#define SEC_PARAM_MAX_KEY_SIZE          16                                      /**< Maximum encryption key size. */

#define DEAD_BEEF                       0xDEADBEEF                              /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */

BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT); //editted                                   /**< BLE NUS service instance. */
NRF_BLE_GATT_DEF(m_gatt);                                                       /**< GATT module instance. */
NRF_BLE_QWR_DEF(m_qwr);                                                         /**< Context for the Queued Write module.*/
BLE_ADVERTISING_DEF(m_advertising);                                             /**< Advertising module instance. */

static uint16_t m_conn_handle = BLE_CONN_HANDLE_INVALID;                        /**< Handle of the current connection. */

/* YOUR_JOB: Declare all services structure your application is using
 *  BLE_XYZ_DEF(m_xyz);
 */

// below line editted
 static uint16_t   m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - 3;      //editted      /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */

// YOUR_JOB: Use UUIDs for service(s) used in your application.
static ble_uuid_t m_adv_uuids[] =                                               /**< Universally unique service identifiers. */ //editted
{
    {BLE_UUID_NUS_SERVICE, NUS_SERVICE_UUID_TYPE}
    };


static void advertising_start(bool erase_bonds);


/**@brief Callback 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] 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(DEAD_BEEF, line_num, p_file_name);
}


/**@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:
            advertising_start(false);
            break;

        default:
            break;
    }
}


/**@brief Function for the Timer initialization.
 *
 * @details Initializes the timer module. This creates and starts application timers.
 */
static void timers_init(void)
{
    // Initialize timer module.
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);

    // Create timers.

    /* YOUR_JOB: Create any timers to be used by the application.
                 Below is an example of how to create a timer.
                 For every new timer needed, increase the value of the macro APP_TIMER_MAX_TIMERS by
                 one.
       ret_code_t err_code;
       err_code = app_timer_create(&m_app_timer_id, APP_TIMER_MODE_REPEATED, timer_timeout_handler);
       APP_ERROR_CHECK(err_code); */
}


/**@brief Function for the GAP initialization.
 *
 * @details This function sets up all the necessary GAP (Generic Access Profile) parameters of the
 *          device including the device name, appearance, and the preferred connection parameters.
 */
static void gap_params_init(void)
{
    ret_code_t              err_code;
    ble_gap_conn_params_t   gap_conn_params;
    ble_gap_conn_sec_mode_t sec_mode;

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    err_code = sd_ble_gap_device_name_set(&sec_mode,
                                          (const uint8_t *)DEVICE_NAME,
                                          strlen(DEVICE_NAME));
    APP_ERROR_CHECK(err_code);

    /* YOUR_JOB: Use an appearance value matching the application's use case.
       err_code = sd_ble_gap_appearance_set(BLE_APPEARANCE_);
       APP_ERROR_CHECK(err_code); */

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

    gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
    gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
    gap_conn_params.slave_latency     = SLAVE_LATENCY;
    gap_conn_params.conn_sup_timeout  = CONN_SUP_TIMEOUT;

    err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
    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 Queued Write Module errors.
 *
 * @details A pointer to this function will be passed to each service which may need to inform the
 *          application about an error.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void nrf_qwr_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for handling the YYY Service events.
 * YOUR_JOB implement a service handler function depending on the event the service you are using can generate
 *
 * @details This function will be called for all YY Service events which are passed to
 *          the application.
 *
 * @param[in]   p_yy_service   YY Service structure.
 * @param[in]   p_evt          Event received from the YY Service.
 *
 *
static void on_yys_evt(ble_yy_service_t     * p_yy_service,
                       ble_yy_service_evt_t * p_evt)
{
    switch (p_evt->evt_type)
    {
        case BLE_YY_NAME_EVT_WRITE:
            APPL_LOG("[APPL]: charact written with value %s. ", p_evt->params.char_xx.value.p_str);
            break;

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


/**@brief Function for initializing services that will be used by the application.
 */
static void services_init(void)
{
    uint32_t           err_code;
    ble_nus_init_t     nus_init;
    nrf_ble_qwr_init_t qwr_init = {0};

    // Initialize Queued Write Module.
    qwr_init.error_handler = nrf_qwr_error_handler;

    err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
    APP_ERROR_CHECK(err_code);

    // Initialize NUS.
    memset(&nus_init, 0, sizeof(nus_init));

    //nus_init.data_handler = nus_data_handler;

    err_code = ble_nus_init(&m_nus, &nus_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the Connection Parameters Module.
 *
 * @details This function will be called for all events in the Connection Parameters Module which
 *          are passed to the application.
 *          @note All this function does is to disconnect. This could have been done by simply
 *                setting the disconnect_on_fail config parameter, but instead we use the event
 *                handler mechanism to demonstrate its use.
 *
 * @param[in] p_evt  Event received from the Connection Parameters Module.
 */
static void on_conn_params_evt(ble_conn_params_evt_t * p_evt)
{
    ret_code_t err_code;

    if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
    {
        err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
        APP_ERROR_CHECK(err_code);
    }
}


/**@brief Function for handling a Connection Parameters error.
 *
 * @param[in] nrf_error  Error code containing information about what went wrong.
 */
static void conn_params_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void)
{
    ret_code_t             err_code;
    ble_conn_params_init_t cp_init;

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

    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = BLE_GATT_HANDLE_INVALID;
    cp_init.disconnect_on_fail             = false;
    cp_init.evt_handler                    = on_conn_params_evt;
    cp_init.error_handler                  = conn_params_error_handler;

    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for starting timers.
 */
static void application_timers_start(void)
{
    /* YOUR_JOB: Start your timers. below is an example of how to start a timer.
       ret_code_t err_code;
       err_code = app_timer_start(m_app_timer_id, TIMER_INTERVAL, NULL);
       APP_ERROR_CHECK(err_code); */

}


/**@brief Function for putting the chip into sleep mode.
 *
 * @note This function will not return.
 */
static void sleep_mode_enter(void)
{
    ret_code_t err_code;

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

    // Prepare wakeup buttons.
    err_code = bsp_btn_ble_sleep_mode_prepare();
    APP_ERROR_CHECK(err_code);

    // Go to system-off mode (this function will not return; wakeup will cause a reset).
    err_code = sd_power_system_off();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling advertising events.
 *
 * @details This function will be called for advertising events which are passed to the application.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
    ret_code_t err_code;

    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
            NRF_LOG_INFO("Fast advertising.");
            err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_ADV_EVT_IDLE:
            sleep_mode_enter();
            break;

        default:
            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 = NRF_SUCCESS;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected.");
            // LED indication will be changed when advertising starts.
            break;

        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO("Connected.");
            err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
            APP_ERROR_CHECK(err_code);
            m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
            err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
            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 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 a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_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 bond 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 handling events from the BSP module.
 *
 * @param[in]   event   Event generated when button is pressed.
 */
static void bsp_event_handler(bsp_event_t event)
{
    ret_code_t err_code;

    switch (event)
    {
        case BSP_EVENT_SLEEP:
            sleep_mode_enter();
            break; // BSP_EVENT_SLEEP

        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; // BSP_EVENT_DISCONNECT

        case BSP_EVENT_WHITELIST_OFF:
            if (m_conn_handle == BLE_CONN_HANDLE_INVALID)
            {
                err_code = ble_advertising_restart_without_whitelist(&m_advertising);
                if (err_code != NRF_ERROR_INVALID_STATE)
                {
                    APP_ERROR_CHECK(err_code);
                }
            }
            break; // BSP_EVENT_KEY_0

        default:
            break;
    }
}





/**@brief Function for initializing the Advertising functionality.
 */
static void advertising_init(void)
{
    ret_code_t             err_code;
    ble_advertising_init_t init;

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

    init.advdata.name_type               = BLE_ADVDATA_FULL_NAME;
    init.advdata.include_appearance      = true;
    init.advdata.flags                   = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
    init.advdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.advdata.uuids_complete.p_uuids  = m_adv_uuids;

    init.config.ble_adv_fast_enabled  = true;
    init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
    init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;

    init.evt_handler = on_adv_evt;

    err_code = ble_advertising_init(&m_advertising, &init);
    APP_ERROR_CHECK(err_code);

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}


/**@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 power management.
 */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop).
 *
 * @details If there is no pending log operation, then sleep until next the next event occurs.
 */
static void idle_state_handle(void)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}


/**@brief Function for starting advertising.
 */
static void advertising_start(bool erase_bonds)
{
    if (erase_bonds == true)
    {
        delete_bonds();
        // Advertising is started by PM_EVT_PEERS_DELETED_SUCEEDED event
    }
    else
    {
        ret_code_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);

        APP_ERROR_CHECK(err_code);
    }
}

//void data_send()
//{
//    static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
//    static uint8_t index = 0;
//    uint32_t       err_code;
//
//    data_array[0] = 0;
//    data_array[1] = 1;
//    data_array[2] = 1; 
//
//            
//                    NRF_LOG_DEBUG("Ready to send data over BLE NUS");
//                    NRF_LOG_HEXDUMP_DEBUG(data_array, index);
//
//                   
//                        uint16_t length = (uint16_t)index;
//                        err_code = ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
//   
// 
//}


/**@brief Function for application main entry.
 */
int main(void)
{
    bool erase_bonds;

    // Initialize.
    log_init();
    timers_init();
    //buttons_leds_init(&erase_bonds);
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    advertising_init();
    services_init();
    conn_params_init();
    peer_manager_init();

    // Start execution.
    NRF_LOG_INFO("Template example started.");
    application_timers_start();

    advertising_start(erase_bonds);

    nrf_delay_ms(50); 

    static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
    static uint8_t index = 0;
    uint32_t       err_code;

    data_array[0] = 0;
    data_array[1] = 1;
    data_array[2] = 1; 

            
                    NRF_LOG_DEBUG("Ready to send data over BLE NUS");
                    NRF_LOG_HEXDUMP_DEBUG(data_array, index);

                   
                        uint16_t length = (uint16_t)sizeof(data_array);
                        err_code = ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
                         if ((err_code != NRF_ERROR_INVALID_STATE) &&
                            (err_code != NRF_ERROR_RESOURCES) &&
                            (err_code != NRF_ERROR_NOT_FOUND))
                        {
                            APP_ERROR_CHECK(err_code);
                        }
                     while (err_code == NRF_ERROR_RESOURCES);
                

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


/**
 * @}
 */

I do not start with the BLE_UART example because the example does not run on my PCB (PCB does not advertise with it) for some reason (I am guessing the uart pins are connected to other things on the custom board). 

Thanks.  

[Edvin]

Hello,

Ok, so from the other thread that you posted on, you mention that you use Segger Embedded Studio, so the IDE will flash the softdevice for you. This is not the problem, then.

Since the ble_template example runs and advertises, then it seems like your pcb has an external LFXTAL. (I am just mentioning this because many PCBs don't, and that is a possible cause of the issue when the BLE examples doesn't advertise).

So, that leaves it to be related to the NUS service or the UART.

I suggest that you get familiar with our debugging system, or error_handler.

My bet is that one place in your code you have an APP_ERROR_CHECK(err_code) with an err_code != 0 (==NRF_SUCCESS).

Is it possible for you on your PCB to monitor the logging? In the ble_app_uart example that would be the RTT log, which you can monitor in Segger Embedded Studio.

It probably just writes "Fatal error" at the end of the log, but if you define DEBUG in your preprocessor defines, it should give you the file name, line number and err_code that caused the error.

My guess, if you are running the ble_app_uart example, is that you get a communication error on the physical uart:

        case APP_UART_COMMUNICATION_ERROR:
            APP_ERROR_HANDLER(p_event->data.error_communication);
            break;

You need to either set the UART RX pin to a pin that isn't floating (not connected to anything). This can cause this error. Alternatively, if you don't use the UART, just comment out uart_init() in your main() function.

Or the last option is to comment out APP_ERROR_HANDLER(p_event->data.error_communication); from the APP_UART_COMMUNICATION_ERROR event.

If this is not the problem, then you need to check your log for info on where the error comes from.

Best regards,

Edvin

[noob_with_ucontrollers]

I also had another question, the uart_evt_handle () function is called in case a uart event occurs and the nus_data_handler is called when data is received via BLE right? 
Can we send data via ble using the nus_data_handler?  

[noob_with_ucontrollers]

Yes I meant ble_nus_data_send(). 

I am posting here again as a follow up to my project. I call ble_nus_data_send() in my own custom function which I call in the main loop and it's working great. I started off with the ble_uart example (SDK 15.2).  I can initialize random data arrays and the ble_nus_data_send() will send them to the nrf toolbox when I call it. 

When I could do that successfully, I added SPI initialization and functions to the example to call data via SPI from an ADC. However, my SPI does not work in this project (I see nothing on the CLK pin ((pin #7), no clock signal) and all I see on my NRF Toolbox app is "0xFFFFF...." no matter what the input to my adc.. 

Why would the bluetooth project not allow normal SPI functionality? Where does the "0xFFF" come from? My code does build and flash without errors. 

void my_data_call () {

// Initialize variables 
        
   uint32_t err_code;
   uint16_t length = (uint16_t)m_rx_length;

   // Call to SPI transfer 
                        
memset(m_rx_buf, 0, m_rx_length);
memset(m_tx_buf, 0, m_tx_length);
spi_xfer_done = false;
m_tx_buf [0] = 0x08;   // Start Conversion command 
nrf_gpio_pin_clear (SPI_CS_PIN);
        APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, m_tx_buf, m_tx_length, m_rx_buf, m_rx_length));

        while (!spi_xfer_done)
        {
            __WFE();
        }




 //   Call to BLE SPI  !!

 if(m_conn_handle != BLE_CONN_HANDLE_INVALID) {

                        err_code = ble_nus_data_send(&m_nus, m_rx_buf, &length, m_conn_handle);
                        if ((err_code != NRF_ERROR_INVALID_STATE) &&
                            (err_code != NRF_ERROR_RESOURCES) &&
                            (err_code != NRF_ERROR_NOT_FOUND))
                        {
                            APP_ERROR_CHECK(err_code);
                        }

                        }

[Edvin]

From where do you call my_data_call()? I suspect that you are seeing some interrupt blocking. Are you getting past while (!spi_xfer_done)? If it moves past, are you getting anything in the m_rx_buf? And if m_rx_buf is not empty, are you getting NRF_SUCCESS on ble_nus_data_send?

[noob_with_ucontrollers]

I put my_data_call() in a loop in the main function like this : 

int main(void)
{
   bool erase_bonds;

    // Initialize.
    
//    log_init();
    timers_init();
    buttons_leds_init(&erase_bonds);
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();
    spi_init(); 
     nrf_gpio_cfg_input(SPI_MISO_PIN, NRF_GPIO_PIN_NOPULL); 
    

    // Start execution.
//    printf("\r\nUART started.\r\n");
//    NRF_LOG_INFO("Debug logging for UART over RTT started.");
    advertising_start();
spi_xfer_done = false;
 


     data_array [0] = 0x78; 
     data_array [1] = 0x79; 
     data_array [2] = 0x86; 
     data_array [3] = 0x65; 
     data_array [4] = 0x76;

//     NRF_LOG_DEBUG("Hi there");
    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
        my_data_call(); 
    }
}


/**
 * @}
 */

I put my_data_call() in a for(;;) loop at the end of the Main right after ide_state(). When I did this to send a random character string , I would get proper data. This is why I kept it in the same place for SPI.... 

I checked that my SPI_EVENT_HANDLER is called and spi_xfer_done is true... 

I cannot use LOG or RTT because calling their functions stops my SPI from working entirely (I stop getting a clock signal on Pin 7 SPI_CSK_PIN). Is there another way I can check my m_rx_buf?  

My clock (pin 7 has a clock of 125 kHz), DRDY (pin 10),  chip select (pin 6) pins work normally as I see in the oscilloscope. The MISO pin (pin 9) is fixed at a DC HIGH value, 3.3V (not pulsed but DC), and I think that is why I see a fixed "FFFF..".. 
I though that maybe pin 9 is being somewhere else, so I configure NFCT_PINS_AS_GPIOS in preprocessor settings, I tried a NOPULL config on MISO as described in this new ticket I started (devzone.nordicsemi.com/.../miso-pin-acting-weird) but these things didn't work. 

[Edvin]

What is your SPI connected to actually? What is DRDY? The nRF is the SPI master, right? Are you seeing any data on the MOSI line? There are 4 SPI modes, usually defined in spi_init(). What mode are you trying? Can you try the other modes as well?

BR,

Edvin

[noob_with_ucontrollers]

My nrf52 is connected to an ADC (ads1220) on a custom made PCB, the NRF is the master. They communicate via SPI. I don't use or initialize DRDY. It does not exist anywhere in the software. From my experience running spi with the adc before, using DRDY is not necessary. 

Yes I get proper pulses on the MOSI line (Pin 8), and Clock (pin 7). I checked my DRDY and the ADS seems to be giving out a proper DRDY signal. The only problem is with the MISO pin (Pin 9) that seems to have a DC of 3.3V.... I use MODE_1 because my ADS1220 is compatible with that. 

[Edvin]

Oh. So DRDY is the same as MISO? I base this assumption on e.g. this:
http://www.tij.co.jp/document-viewer/jp/ADS1018-Q1/datasheet/application_and_implementation

 

noob_with_ucontrollers said:

The only problem is with the MISO pin (Pin 9) that seems to have a DC of 3.3V

 Have you defined the MISO pin as an output? I don't understand exactly what you mean. Or do you mean that the sensor is keeping it high? Can you try to measure the voltage between GND and MISO on the nRF (pin 9), and between GND and the data out (MISO? DRDY?) on the sensor?

BR,

Edvin