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Trying to integrate bonding into uart example, but peer manager event handler never being called

I developed a functioning application that advertises with Nordic UART Service, connects to a smartphone application, then reads various sensor data using the SAADC and transmits data to a smartphone. I now want to integrate bonding into the application. I have done a lot of reading online, checking examples, and borrowed some code from the ble_app_template example. 

This strategy seemed to work on my iPhone with nRF Connect at first. Upon connection, my application would enter the pm_evt_handler() function and the PM_EVT_CONN_SEC_SUCCEEDED case within peer_manager_handler.c, function pm_handler_evt_log(), would be entered. My debug console would log That the connection was secured, with procedure: encryption. I also noticed that my application was listed and available in my iPhone's bluetooth settings, which had never happened before (only appeared in scans through nRF Connect or similar ble applications). I then wanted to experiment with deleting bonds from with my application, but after doing so my program would enter the PM_EVT_CONN_SEC_FAILED case and print the connection security had failed with error 4102. Research pointed towards the error coming from bonds being deleted on my peripheral device, but not the smartphone. So I selected "forget this device" from within my iPhone bluetooth settings. 

I restarted my application without deleting bonds, then received some sort of database error. I cannot remember what the error was exactly and I did not save it, and can no longer reproduce it. I cannot reproduce it because now my application never enters the peer manager event handler function, pm_evt_handler(). The peer manager is being initialized, but my application seems to have lost all functionality with regards to the peer manager and I have not changed the code at all.

Can somebody please help me try to pinpont what I am doing wrong? My application is based off of the uart example, and I integrated peer manager functions from the ble_app_template example project. My application still functions fine with regards to reading SAADC values, timers, regular advertising/connection, etc, but has no peer manager behavior. Below I am pasting my main.c and sdk_config.h files. Please ignore functions related to SAADC, reading values, etc - there are many parts I should clean up and optimize that I am already aware of. 

Code related to peer manager are: lines 136-143, 230-250, 583-612, 616-624, 1212-1234. I began writing this application when I was first learning C, so code as seen in function "format_bluetooh_packet()" is painful to look at and is on my to-do to fix. All i want right now is to get peer manager working and then I can clean up/refactor older code. 

--

main.c

/**
 * 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_uart_over_ble_main main.c
 * @{
 * @ingroup  ble_sdk_app_nus_eval
 * @brief    UART over BLE application main file.
 *
 * This file contains the source code for a sample application that uses the 
 * Nordic UART service.
 * This application uses the @ref srvlib_conn_params module.
 */


#include <stdint.h>
#include <string.h>
#include "nordic_common.h"
#include "boards.h"

#include "nrf.h"
#include "nrf_sdh.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdh_ble.h"
#include "nrf_ble_qwr.h"
#include "nrf_pwr_mgmt.h"
#include "nrf_ble_gatt.h"
#include "nrf_saadc.h"
#include "nrf_drv_clock.h"
#include "nrf_delay.h"
#include "nrf_drv_gpiote.h"
#include "nrf_drv_saadc.h"
#include "nrf_drv_ppi.h"
#include "nrf_drv_timer.h"

#include "nrfx_ppi.h"
#include "nrfx_pwm.h"
#include "nrf_timer.h"
#include "nrfx_saadc.h"

#include "ble_nus.h"
#include "ble_hci.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"

#include "app_timer.h"
#include "app_uart.h"
#include "app_util_platform.h"
#include "app_fifo.h"
#include "app_pwm.h"
#include "app_error.h"

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

// Included for peer manager
#include "nrf_fstorage.h"
#include "nrf_fstorage_sd.h"
#include "fds.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include "ble_conn_state.h"

#if defined (UART_PRESENT)
#include "nrf_uart.h"
#endif
#if defined (UARTE_PRESENT)
#include "nrf_uarte.h"
#endif



#define APP_BLE_CONN_CFG_TAG            1                                           /**< A tag identifying the SoftDevice BLE configuration. */

#define DEVICE_NAME                     "Lura_Health"                               /**< Name of device. Will be included in the advertising data. */
#define NUS_SERVICE_UUID_TYPE           BLE_UUID_TYPE_VENDOR_BEGIN                  /**< UUID type for the Nordic UART Service (vendor specific). */

#define APP_BLE_OBSERVER_PRIO           3                                           /**< Application's BLE observer priority. You shouldn't need to modify this value. */

#define APP_ADV_INTERVAL                510                                         /**< The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */

#define APP_ADV_DURATION                18000                                       /**< The advertising duration (180 seconds) in units of 10 milliseconds. */

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS)             /**< Minimum acceptable connection interval (20 ms), Connection interval uses 1.25 ms units. */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(75, UNIT_1_25_MS)             /**< Maximum acceptable connection interval (75 ms), Connection interval uses 1.25 ms units. */
#define SLAVE_LATENCY                   0                                           /**< Slave latency. */
#define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)             /**< Connection supervisory timeout (4 seconds), Supervision Timeout uses 10 ms units. */
#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 DEAD_BEEF                       0xDEADBEEF                                  /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */

#define UART_TX_BUF_SIZE                256                                         /**< UART TX buffer size. */
#define UART_RX_BUF_SIZE                256                                         /**< UART RX buffer size. */

#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 SAMPLES_IN_BUFFER               11                                          /**< SAADC buffer > */

#define NRF_SAADC_CUSTOM_CHANNEL_CONFIG_SE(PIN_P) \
{                                                   \
    .resistor_p = NRF_SAADC_RESISTOR_DISABLED,      \
    .resistor_n = NRF_SAADC_RESISTOR_DISABLED,      \
    .gain       = NRF_SAADC_GAIN1_5,                \
    .reference  = NRF_SAADC_REFERENCE_INTERNAL,     \
    .acq_time   = NRF_SAADC_ACQTIME_10US,           \
    .mode       = NRF_SAADC_MODE_SINGLE_ENDED,      \
    .burst      = NRF_SAADC_BURST_DISABLED,         \
    .pin_p      = (nrf_saadc_input_t)(PIN_P),       \
    .pin_n      = NRF_SAADC_INPUT_DISABLED          \
}

/* UNDEFS FOR DEBUGGING */
#undef RX_PIN_NUMBER
#undef RTS_PIN_NUMBER
#undef LED_4          
#undef LED_STOP       

BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT);                                   /**< 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. */
APP_TIMER_DEF(m_timer_id);

static uint16_t   m_conn_handle          = BLE_CONN_HANDLE_INVALID;                 /**< Handle of the current connection. */
static uint16_t   m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - 3;            /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
static ble_uuid_t m_adv_uuids[]          =                                          /**< Universally unique service identifier. */
{
    {BLE_UUID_NUS_SERVICE, NUS_SERVICE_UUID_TYPE}
};


/* Lura Health nRF52810 port assignments */
#define ENABLE_ANALOG_PIN 4

/* GLOBALS */
static   uint32_t AVG_PH_VAL       = 0;
static   uint32_t AVG_BATT_VAL     = 0;
static   uint32_t AVG_TEMP_VAL     = 0;
bool              PH_IS_READ       = false;
bool              BATTERY_IS_READ  = false;
bool              SAADC_CALIBRATED = false;
bool              CONNECTION_MADE  = false;

static const nrf_drv_timer_t   m_timer = NRF_DRV_TIMER_INSTANCE(1);
static       nrf_saadc_value_t m_buffer_pool[1][SAMPLES_IN_BUFFER];
static       nrf_ppi_channel_t m_ppi_channel;


// Forward declarations
static inline void enable_pH_voltage_reading  (void);
static inline void enable_switch              (void);
static inline void check_reed_switch          (void);
static inline void disable_pH_voltage_reading (void);
static inline void saadc_init                 (void);
static inline void enable_analog_pin          (void);
static inline void disable_analog_pin         (void);
static        void advertising_start          (bool erase_bonds);


/**@brief Function for assert macro callback.
 *
 * @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 analyse 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(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);

    NRF_LOG_INFO("INSIDE pm_evt_handler()\n");
    NRF_LOG_FLUSH();

    switch (p_evt->evt_id)
    {
        case PM_EVT_PEERS_DELETE_SUCCEEDED:
            advertising_start(false);
            break;
        case PM_EVT_BONDED_PEER_CONNECTED:  
            NRF_LOG_INFO("PM_EVT_BONDED_PEER_CONNECTED");
            NRF_LOG_FLUSH();
            break;
        default:
            break;
    }
}


/**@brief Function for initializing the timer module.
 */
static inline void timers_init(void)
{
    uint32_t err_code;
    err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for the GAP initialization.
 *
 * @details This function will set up all the necessary GAP (Generic Access 
 *          Profile) parameters of the device. It also sets the permissions 
 *          and appearance.
 */
static inline void gap_params_init(void)
{
    uint32_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);

    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 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 data from the Nordic UART Service.
 *
 * @details This function will process the data received from the Nordic UART 
 *          BLE Service and send it to the UART module.
 *
 * @param[in] p_evt       Nordic UART Service event.
 */
/**@snippet [Handling the data received over BLE] */
static inline void nus_data_handler(ble_nus_evt_t * p_evt)
{

    if (p_evt->type == BLE_NUS_EVT_RX_DATA)
    {
        uint32_t err_code;

        NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on UART.");
        NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, 
                                            p_evt->params.rx_data.length);

        for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++)
        {
            do
            {
                err_code = app_uart_put(p_evt->params.rx_data.p_data[i]);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", 
                                                                    err_code);
                    APP_ERROR_CHECK(err_code);
                }
            } while (err_code == NRF_ERROR_BUSY);
        }
        if (p_evt->params.rx_data.p_data[p_evt->params.rx_data.length - 1] == '\r')
        {
            while (app_uart_put('\n') == NRF_ERROR_BUSY);
        }
    }

}
/**@snippet [Handling the data received over BLE] */


/**@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 an event from 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)
{
    uint32_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 errors from the Connection Parameters module.
 *
 * @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)
{
    uint32_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 putting the chip into sleep mode.
 *
 * @note This function will not return.
 */
static void sleep_mode_enter(void)
{
    uint32_t err_code; 

    // Go to system-off mode (function will not return; wakeup causes 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)
{
    uint32_t err_code;

    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
            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)
{
    uint32_t err_code;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            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);
            CONNECTION_MADE = true;

            NRF_LOG_INFO("CONNECTION MADE \n");

            break;

        case BLE_GAP_EVT_DISCONNECTED:
            if(p_ble_evt->evt.gap_evt.params.disconnected.reason  == 
                                                    BLE_HCI_CONNECTION_TIMEOUT)
            {
                //disconnect_reason is BLE_HCI_CONNECTION_TIMEOUT
                NRF_LOG_INFO("connection timeout\n");
            }
            // LED indication will be changed when advertising starts.
            m_conn_handle = BLE_CONN_HANDLE_INVALID;
            CONNECTION_MADE = false;
            NRF_LOG_INFO("DISCONNECTED\n");
            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_GAP_EVT_SEC_PARAMS_REQUEST:
//            // Pairing not supported
//            err_code = 
//                sd_ble_gap_sec_params_reply(m_conn_handle, 
//                                            BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, 
//                                            NULL, NULL);
//            APP_ERROR_CHECK(err_code);
//            break;

//        case BLE_GATTS_EVT_SYS_ATTR_MISSING:
//            // No system attributes have been stored.
//            err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
//            APP_ERROR_CHECK(err_code);
//            break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            err_code = 
                sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                      BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            CONNECTION_MADE = false;
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            err_code = 
                sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                      BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            CONNECTION_MADE = false;
            APP_ERROR_CHECK(err_code);
            break;

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


/**@brief Function for the SoftDevice initialization.
 *
 * @details This function 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 initializing the Advertising functionality.
 */
static void advertising_init(void)
{
    uint32_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 = false;
    init.advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;

    init.srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.srdata.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 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)
{
    UNUSED_RETURN_VALUE(NRF_LOG_PROCESS());
    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);
    }
}


/* This function sets enable pin for ISFET circuitry to HIGH
 */
static inline void enable_analog_circuit(void)
{
    nrf_drv_gpiote_out_config_t config = NRFX_GPIOTE_CONFIG_OUT_SIMPLE(false);
    if(nrf_drv_gpiote_is_init() == false) {
          nrf_drv_gpiote_init();
    }
    nrf_drv_gpiote_out_init(ENABLE_ANALOG_PIN, &config);
    nrf_drv_gpiote_out_set(ENABLE_ANALOG_PIN);
}

/* This function sets enable pin for ISFET circuitry to LOW
 */
static inline void disable_analog_pin(void)
{
     // Redundant, but follows design
     nrfx_gpiote_uninit();
}

void timer_handler(nrf_timer_event_t event_type, void * p_context)
{
    // To Add Later
}


static inline void saadc_sampling_event_init(void)
{
    ret_code_t err_code;

    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
    timer_cfg.bit_width = NRF_TIMER_BIT_WIDTH_32;
    err_code = nrf_drv_timer_init(&m_timer, &timer_cfg, timer_handler);
    APP_ERROR_CHECK(err_code);

    /* setup m_timer for compare event every 15us */
    uint32_t ticks = nrf_drv_timer_us_to_ticks(&m_timer, 35);
    nrf_drv_timer_extended_compare(&m_timer,
                                   NRF_TIMER_CC_CHANNEL0,
                                   ticks,
                                   NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK,
                                   false);
    nrf_drv_timer_enable(&m_timer);

    uint32_t timer_compare_event_addr = 
                nrf_drv_timer_compare_event_address_get(&m_timer,
                                                        NRF_TIMER_CC_CHANNEL0);
    uint32_t saadc_sample_task_addr   = nrf_drv_saadc_sample_task_get();

    /* setup ppi channel so that timer compare event triggers task in SAADC */
    err_code = nrf_drv_ppi_channel_alloc(&m_ppi_channel);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_ppi_channel_assign(m_ppi_channel,
                                          timer_compare_event_addr,
                                          saadc_sample_task_addr);
    APP_ERROR_CHECK(err_code);
}


static inline void saadc_sampling_event_enable(void)
{
    ret_code_t err_code = nrf_drv_ppi_channel_enable(m_ppi_channel);
    APP_ERROR_CHECK(err_code);
}


/* Function for converting numbers > 9 to byte arrays in ASCII format
 * @params: Averaged value read from SAADC, ptr to byte array
 */
static inline void num_to_byte_arr(uint8_t *data_arr, uint32_t avg_val)
{
    uint8_t dig1, dig2, dig3;
    if(avg_val > 99) {
        dig1 = avg_val % 10;
        dig2 = ((avg_val % 100) - dig1) / 10;
        dig3 = (avg_val - (dig1 + (dig2 * 10))) / 100;
    
        // Convert to ASCII values
        data_arr[0] = dig3 + 48;
        data_arr[1] = dig2 + 48;
        data_arr[2] = dig1 + 48;
    }
    else if(avg_val > 9) {
        dig3 = 0;
        dig1 = avg_val % 10;
        dig2 = ((avg_val % 100) - dig1) / 10;

        // Convert to ASCII values
        data_arr[0] = dig2 + 48;
        data_arr[1] = dig1 + 48;
    }
    else {
        dig3 = 0;
        dig2 = 0;
        dig1 = avg_val;
        // Convert to ASCII value
        data_arr[0] = avg_val + 48;
    }
}

static inline void restart_saadc(void)
{
    nrfx_timer_uninit(&m_timer);
    nrfx_ppi_channel_free(m_ppi_channel);
    nrfx_saadc_uninit();
    while(nrfx_saadc_is_busy()) {
        // make sure SAADC is not busy
    }
    enable_pH_voltage_reading(); 
}

// Integers can have maximum 3 digits with 8-bit SAADC output
static inline int length_of_int(int x)
{
    if (x >= 100)        return 3;
    if (x >= 10)         return 2;
    return 1;
}

/* This function combines the ph_data and temp_data into one bluetooth
 * packet. The packet follows the format [ph_data,temp_data\n] where
 * data fields are between 1-3 bytes each (one per digit). 
 */
static inline uint8_t* format_bluetooth_packet(uint8_t*  ph_data,  
                                               uint8_t*  batt_data,    
                                               uint8_t*  temp_data,
                                               uint8_t*  total_packet, 
                                               uint16_t* total_size)
{
    num_to_byte_arr(temp_data, AVG_TEMP_VAL);
    num_to_byte_arr(batt_data, AVG_BATT_VAL);
    // Plus two for comma, plus one for EOL
    *total_size = length_of_int(AVG_PH_VAL) + length_of_int(AVG_TEMP_VAL) 
                                            + length_of_int(AVG_BATT_VAL) + 2 + 1;
    NRF_LOG_INFO("TOTAL SIZE: %d\n", *total_size);
    total_packet = (uint8_t*) malloc(sizeof(uint8_t) * (*total_size));
    // Copy pH data, copy temp data, add comma and EOL
    memcpy(total_packet, ph_data, length_of_int(AVG_PH_VAL));
    memcpy(total_packet + length_of_int(AVG_PH_VAL) + 1, 
                        temp_data, length_of_int(AVG_TEMP_VAL));
    memcpy(total_packet + length_of_int(AVG_PH_VAL) + 2 + length_of_int(AVG_TEMP_VAL), 
                        batt_data, length_of_int(AVG_BATT_VAL));
    total_packet[length_of_int(AVG_PH_VAL)] = 44; // comma
    total_packet[length_of_int(AVG_PH_VAL)+1+length_of_int(AVG_TEMP_VAL)] = 44; // comma
    total_packet[*total_size - 1] = 10; // EOL
    return total_packet;
}

static inline uint8_t* create_bluetooth_packet(uint32_t ph_val,
                                               uint32_t batt_val,        
                                               uint32_t temp_val, 
                                               uint8_t* total_packet,  
                                               uint16_t* total_size)
{
    uint8_t threedig_PH_data  [3] = {0, 0, 0};
    uint8_t threedig_BATT_data[3] = {0, 0, 0};
    uint8_t threedig_TEMP_data[3] = {0, 0, 0};
    uint8_t twodig_PH_data    [2] = {0, 0};
    uint8_t twodig_BATT_data  [2] = {0, 0};
    uint8_t twodig_TEMP_data  [2] = {0, 0};
    uint8_t onedig_PH_data    [1] = {0};
    uint8_t onedig_BATT_data  [1] = {0};
    uint8_t onedig_TEMP_data  [1] = {0};

    uint8_t* packet;

    if(AVG_PH_VAL > 99) {
        num_to_byte_arr(threedig_PH_data, AVG_PH_VAL);
        // Convert temp number to appropriate byte array
        if(AVG_TEMP_VAL > 99) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(threedig_PH_data, threedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(threedig_PH_data, twodig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(threedig_PH_data, onedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else if(AVG_TEMP_VAL > 9) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(threedig_PH_data, threedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(threedig_PH_data, twodig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(threedig_PH_data, onedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(threedig_PH_data, threedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(threedig_PH_data, twodig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(threedig_PH_data, onedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
        }
    }
    else if(AVG_PH_VAL > 9) {
        num_to_byte_arr(twodig_PH_data, AVG_PH_VAL);
        // Convert temp number to appropriate byte array
        if(AVG_TEMP_VAL > 99) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(twodig_PH_data, threedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(twodig_PH_data, twodig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(twodig_PH_data, onedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else if(AVG_TEMP_VAL > 9) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(twodig_PH_data, threedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(twodig_PH_data, twodig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(twodig_PH_data, onedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else 
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(twodig_PH_data, threedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(twodig_PH_data, twodig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(twodig_PH_data, onedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
    }
    else {
        num_to_byte_arr(onedig_PH_data, AVG_PH_VAL);
        // Convert temp number to appropriate byte array
        if(AVG_TEMP_VAL > 99) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(onedig_PH_data, threedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(onedig_PH_data, twodig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(onedig_PH_data, onedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else if(AVG_TEMP_VAL > 9) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(onedig_PH_data, threedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(onedig_PH_data, twodig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(onedig_PH_data, onedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(onedig_PH_data, threedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(onedig_PH_data, twodig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(onedig_PH_data, onedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
        }
    }
    return packet;    
}


/**
 * Function is called when SAADC reading event is done. First done event
 * reads pH input, stores in global variable. Second reading stores
 * pH data, combines pH and temp data into a comma-seperated string,
 * then transmits via BLE.
 *
 * BUG: p_buffer[0] is always '0' when reading pH at high frequency.
 *      Workaround is to average values besides 1, divide by 
 *      samples_in_buffer -1 .
 */
static inline void saadc_callback(nrf_drv_saadc_evt_t const * p_event)
{
    if (p_event->type == NRF_DRV_SAADC_EVT_DONE) 
    {
        ret_code_t err_code;
        uint16_t   total_size;
        uint32_t avg_saadc_reading = 0;
        // Byte array to store total packet
        uint8_t* total_packet;

        err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, 
                                                            SAMPLES_IN_BUFFER); 
        APP_ERROR_CHECK(err_code);
        // Sum and average SAADC values
        for (int i = 1; i < SAMPLES_IN_BUFFER; i++)
        {
            if (p_event->data.done.p_buffer[i] < 0) {
                avg_saadc_reading += 0;
            } 
            else {
                avg_saadc_reading += p_event->data.done.p_buffer[i];
            }
        }
        avg_saadc_reading = avg_saadc_reading/(SAMPLES_IN_BUFFER - 1); 
        // If ph has not been read, read it then restart SAADC to read temp
        if (!PH_IS_READ) {
            AVG_PH_VAL = avg_saadc_reading;
            PH_IS_READ = true;
            // Uninit saadc peripheral, restart saadc, enable sampling event
            NRF_LOG_INFO("read pH val, restarting: %d", AVG_PH_VAL);
            NRF_LOG_FLUSH();
            restart_saadc();
        } 
        // If pH has been read but not battery, read battery then restart
        else if (!(PH_IS_READ && BATTERY_IS_READ)) {
            AVG_BATT_VAL = avg_saadc_reading;
            NRF_LOG_INFO("read batt val, restarting: %d", AVG_BATT_VAL);
            NRF_LOG_FLUSH();
            BATTERY_IS_READ = true;
            restart_saadc();
        }
        // Once temp, batter and ph have been read, create and send data in packet
        else {
            AVG_TEMP_VAL = avg_saadc_reading;
            NRF_LOG_INFO("read temp val, restarting: %d", AVG_TEMP_VAL);
            NRF_LOG_FLUSH();
            // Convert pH number to appropriate byte array
            total_packet = create_bluetooth_packet((uint32_t)AVG_PH_VAL, 
                                                   (uint32_t)AVG_BATT_VAL,
                                                   (uint32_t)AVG_TEMP_VAL, 
                                                   total_packet, &total_size);
            // Send data
            err_code = ble_nus_data_send(&m_nus, total_packet, 
                                         &total_size, m_conn_handle);
            // reset global control boolean
            PH_IS_READ = false;
            BATTERY_IS_READ = false;
            // Free dynamic array
            free(total_packet);
            // Turn off peripherals
            NRF_LOG_INFO("BLUETOOTH DATA SENT\n");
            NRF_LOG_FLUSH();
            disable_pH_voltage_reading();
 
            NRF_LOG_INFO("SAADC DISABLED\n");
            NRF_LOG_FLUSH();
        }
    }
}


/* Reads pH transducer output
 */
void saadc_init(void)
{
    ret_code_t err_code;
    nrf_saadc_input_t ANALOG_INPUT;
    // Change pin depending on global control boolean
    if (!PH_IS_READ) {
        NRF_LOG_INFO("Setting saadc input to AIN1\n");
        ANALOG_INPUT = NRF_SAADC_INPUT_AIN1;
    }
    else if (!(PH_IS_READ && BATTERY_IS_READ)) {
        NRF_LOG_INFO("Setting saadc input to AIN3\n");
        ANALOG_INPUT = NRF_SAADC_INPUT_AIN3;
    }
    else {
        NRF_LOG_INFO("Setting saadc input to AIN0\n");
        ANALOG_INPUT = NRF_SAADC_INPUT_AIN0;        
    }

    nrf_saadc_channel_config_t channel_config =
            NRF_SAADC_CUSTOM_CHANNEL_CONFIG_SE(ANALOG_INPUT);

    err_code = nrf_drv_saadc_init(NULL, saadc_callback);
    APP_ERROR_CHECK(err_code);

    /*
     * BUG: calibration never completes
     */

    // Calibrate offset
    // if(!SAADC_CALIBRATED) {
    //     while (nrfx_saadc_calibrate_offset() != NRFX_SUCCESS) {
    //         NRF_LOG_INFO("calibration does not equal success\n");
    //         NRF_LOG_FLUSH();
    //         nrf_delay_us(10);
    //     }
    //     SAADC_CALIBRATED = true;
    //     while (nrfx_saadc_is_busy()) {
    //         NRF_LOG_INFO("saadc busy while restarting\n");
    //         NRF_LOG_FLUSH();
    //         nrf_delay_ms(1000);
    //     }
    // }   

    err_code = nrf_drv_saadc_channel_init(0, &channel_config);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_buffer_convert(m_buffer_pool[0], SAMPLES_IN_BUFFER);
    APP_ERROR_CHECK(err_code);
}


/* This function initializes and enables SAADC sampling
 */
static inline void enable_pH_voltage_reading(void)
{
    saadc_init();
    saadc_sampling_event_init();
    saadc_sampling_event_enable();
    nrf_pwr_mgmt_run();
}

/* Function unitializes and disables SAADC sampling, restarts 1 second timer
 */
static inline void disable_pH_voltage_reading(void)
{
    nrfx_timer_uninit(&m_timer);
    nrfx_ppi_channel_free(m_ppi_channel);
    nrfx_saadc_uninit();

    // *** DISABLE ENABLE ***
    disable_analog_pin();

    // Restart timer
    ret_code_t err_code;
    err_code = app_timer_start(m_timer_id, APP_TIMER_TICKS(1500), NULL);
    APP_ERROR_CHECK(err_code);
    nrf_pwr_mgmt_run();

    NRF_LOG_INFO("TIMER RESTARTED (disable_ph_voltage_reading)\n");
    NRF_LOG_FLUSH();
}

static inline void single_shot_timer_handler()
{
    // disable timer
    ret_code_t err_code;
    err_code = app_timer_stop(m_timer_id);

    // Delay to ensure appropriate timing between
    enable_analog_circuit();       
    // PWM output, ISFET capacitor, etc
    nrf_delay_us(2000);              
    // Begin SAADC initialization/start
    enable_pH_voltage_reading();
}

/**@brief Function for handling events from the GATT library. */
void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
{
    if ((m_conn_handle == p_evt->conn_handle) && 
        (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED))
    {
        m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH 
                                                                 - HANDLE_LENGTH;

        ret_code_t err_code;

         // Create application timer
        err_code = app_timer_create(&m_timer_id,
                                    APP_TIMER_MODE_SINGLE_SHOT,
                                    single_shot_timer_handler);
        APP_ERROR_CHECK(err_code);
        
        // 1 second timer intervals
        err_code = app_timer_start(m_timer_id, APP_TIMER_TICKS(2000), NULL);
        APP_ERROR_CHECK(err_code);

        NRF_LOG_INFO("TIMER STARTED (gatt_evt_handler) \n");
        NRF_LOG_FLUSH();

        nrf_pwr_mgmt_run();
    }
    NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
                  p_gatt->att_mtu_desired_central,
                  p_gatt->att_mtu_desired_periph);
}

/**@brief Function for initializing the GATT library. */
void gatt_init(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, 
                                               NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
}

/**@brief Application main function.
 */
int main(void)
{
    bool erase_bonds = false;

    log_init();
    timers_init();
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();
    peer_manager_init();
    // Initial pin state is low
    disable_analog_pin();
    advertising_start(erase_bonds);
    // Enter main loop.
    while (true)
    {
        idle_state_handle();
    } 
}

/*
 * @}
 */

sdk_config.h

/**
 * 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_uart_over_ble_main main.c
 * @{
 * @ingroup  ble_sdk_app_nus_eval
 * @brief    UART over BLE application main file.
 *
 * This file contains the source code for a sample application that uses the 
 * Nordic UART service.
 * This application uses the @ref srvlib_conn_params module.
 */


#include <stdint.h>
#include <string.h>
#include "nordic_common.h"
#include "boards.h"

#include "nrf.h"
#include "nrf_sdh.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdh_ble.h"
#include "nrf_ble_qwr.h"
#include "nrf_pwr_mgmt.h"
#include "nrf_ble_gatt.h"
#include "nrf_saadc.h"
#include "nrf_drv_clock.h"
#include "nrf_delay.h"
#include "nrf_drv_gpiote.h"
#include "nrf_drv_saadc.h"
#include "nrf_drv_ppi.h"
#include "nrf_drv_timer.h"

#include "nrfx_ppi.h"
#include "nrfx_pwm.h"
#include "nrf_timer.h"
#include "nrfx_saadc.h"

#include "ble_nus.h"
#include "ble_hci.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"

#include "app_timer.h"
#include "app_uart.h"
#include "app_util_platform.h"
#include "app_fifo.h"
#include "app_pwm.h"
#include "app_error.h"

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

// Included for peer manager
#include "nrf_fstorage.h"
#include "nrf_fstorage_sd.h"
#include "fds.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include "ble_conn_state.h"

#if defined (UART_PRESENT)
#include "nrf_uart.h"
#endif
#if defined (UARTE_PRESENT)
#include "nrf_uarte.h"
#endif



#define APP_BLE_CONN_CFG_TAG            1                                           /**< A tag identifying the SoftDevice BLE configuration. */

#define DEVICE_NAME                     "Lura_Health"                               /**< Name of device. Will be included in the advertising data. */
#define NUS_SERVICE_UUID_TYPE           BLE_UUID_TYPE_VENDOR_BEGIN                  /**< UUID type for the Nordic UART Service (vendor specific). */

#define APP_BLE_OBSERVER_PRIO           3                                           /**< Application's BLE observer priority. You shouldn't need to modify this value. */

#define APP_ADV_INTERVAL                510                                         /**< The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */

#define APP_ADV_DURATION                18000                                       /**< The advertising duration (180 seconds) in units of 10 milliseconds. */

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS)             /**< Minimum acceptable connection interval (20 ms), Connection interval uses 1.25 ms units. */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(75, UNIT_1_25_MS)             /**< Maximum acceptable connection interval (75 ms), Connection interval uses 1.25 ms units. */
#define SLAVE_LATENCY                   0                                           /**< Slave latency. */
#define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)             /**< Connection supervisory timeout (4 seconds), Supervision Timeout uses 10 ms units. */
#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 DEAD_BEEF                       0xDEADBEEF                                  /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */

#define UART_TX_BUF_SIZE                256                                         /**< UART TX buffer size. */
#define UART_RX_BUF_SIZE                256                                         /**< UART RX buffer size. */

#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 SAMPLES_IN_BUFFER               11                                          /**< SAADC buffer > */

#define NRF_SAADC_CUSTOM_CHANNEL_CONFIG_SE(PIN_P) \
{                                                   \
    .resistor_p = NRF_SAADC_RESISTOR_DISABLED,      \
    .resistor_n = NRF_SAADC_RESISTOR_DISABLED,      \
    .gain       = NRF_SAADC_GAIN1_5,                \
    .reference  = NRF_SAADC_REFERENCE_INTERNAL,     \
    .acq_time   = NRF_SAADC_ACQTIME_10US,           \
    .mode       = NRF_SAADC_MODE_SINGLE_ENDED,      \
    .burst      = NRF_SAADC_BURST_DISABLED,         \
    .pin_p      = (nrf_saadc_input_t)(PIN_P),       \
    .pin_n      = NRF_SAADC_INPUT_DISABLED          \
}

/* UNDEFS FOR DEBUGGING */
#undef RX_PIN_NUMBER
#undef RTS_PIN_NUMBER
#undef LED_4          
#undef LED_STOP       

BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT);                                   /**< 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. */
APP_TIMER_DEF(m_timer_id);

static uint16_t   m_conn_handle          = BLE_CONN_HANDLE_INVALID;                 /**< Handle of the current connection. */
static uint16_t   m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - 3;            /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
static ble_uuid_t m_adv_uuids[]          =                                          /**< Universally unique service identifier. */
{
    {BLE_UUID_NUS_SERVICE, NUS_SERVICE_UUID_TYPE}
};


/* Lura Health nRF52810 port assignments */
#define ENABLE_ANALOG_PIN 4

/* GLOBALS */
static   uint32_t AVG_PH_VAL       = 0;
static   uint32_t AVG_BATT_VAL     = 0;
static   uint32_t AVG_TEMP_VAL     = 0;
bool              PH_IS_READ       = false;
bool              BATTERY_IS_READ  = false;
bool              SAADC_CALIBRATED = false;
bool              CONNECTION_MADE  = false;

static const nrf_drv_timer_t   m_timer = NRF_DRV_TIMER_INSTANCE(1);
static       nrf_saadc_value_t m_buffer_pool[1][SAMPLES_IN_BUFFER];
static       nrf_ppi_channel_t m_ppi_channel;


// Forward declarations
static inline void enable_pH_voltage_reading  (void);
static inline void enable_switch              (void);
static inline void check_reed_switch          (void);
static inline void disable_pH_voltage_reading (void);
static inline void saadc_init                 (void);
static inline void enable_analog_pin          (void);
static inline void disable_analog_pin         (void);
static        void advertising_start          (bool erase_bonds);


/**@brief Function for assert macro callback.
 *
 * @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 analyse 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(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);

    NRF_LOG_INFO("INSIDE pm_evt_handler()\n");
    NRF_LOG_FLUSH();

    switch (p_evt->evt_id)
    {
        case PM_EVT_PEERS_DELETE_SUCCEEDED:
            advertising_start(false);
            break;
        case PM_EVT_BONDED_PEER_CONNECTED:  
            NRF_LOG_INFO("PM_EVT_BONDED_PEER_CONNECTED");
            NRF_LOG_FLUSH();
            break;
        default:
            break;
    }
}


/**@brief Function for initializing the timer module.
 */
static inline void timers_init(void)
{
    uint32_t err_code;
    err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for the GAP initialization.
 *
 * @details This function will set up all the necessary GAP (Generic Access 
 *          Profile) parameters of the device. It also sets the permissions 
 *          and appearance.
 */
static inline void gap_params_init(void)
{
    uint32_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);

    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 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 data from the Nordic UART Service.
 *
 * @details This function will process the data received from the Nordic UART 
 *          BLE Service and send it to the UART module.
 *
 * @param[in] p_evt       Nordic UART Service event.
 */
/**@snippet [Handling the data received over BLE] */
static inline void nus_data_handler(ble_nus_evt_t * p_evt)
{

    if (p_evt->type == BLE_NUS_EVT_RX_DATA)
    {
        uint32_t err_code;

        NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on UART.");
        NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, 
                                            p_evt->params.rx_data.length);

        for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++)
        {
            do
            {
                err_code = app_uart_put(p_evt->params.rx_data.p_data[i]);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", 
                                                                    err_code);
                    APP_ERROR_CHECK(err_code);
                }
            } while (err_code == NRF_ERROR_BUSY);
        }
        if (p_evt->params.rx_data.p_data[p_evt->params.rx_data.length - 1] == '\r')
        {
            while (app_uart_put('\n') == NRF_ERROR_BUSY);
        }
    }

}
/**@snippet [Handling the data received over BLE] */


/**@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 an event from 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)
{
    uint32_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 errors from the Connection Parameters module.
 *
 * @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)
{
    uint32_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 putting the chip into sleep mode.
 *
 * @note This function will not return.
 */
static void sleep_mode_enter(void)
{
    uint32_t err_code; 

    // Go to system-off mode (function will not return; wakeup causes 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)
{
    uint32_t err_code;

    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
            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)
{
    uint32_t err_code;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            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);
            CONNECTION_MADE = true;

            NRF_LOG_INFO("CONNECTION MADE \n");

            break;

        case BLE_GAP_EVT_DISCONNECTED:
            if(p_ble_evt->evt.gap_evt.params.disconnected.reason  == 
                                                    BLE_HCI_CONNECTION_TIMEOUT)
            {
                //disconnect_reason is BLE_HCI_CONNECTION_TIMEOUT
                NRF_LOG_INFO("connection timeout\n");
            }
            // LED indication will be changed when advertising starts.
            m_conn_handle = BLE_CONN_HANDLE_INVALID;
            CONNECTION_MADE = false;
            NRF_LOG_INFO("DISCONNECTED\n");
            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_GAP_EVT_SEC_PARAMS_REQUEST:
//            // Pairing not supported
//            err_code = 
//                sd_ble_gap_sec_params_reply(m_conn_handle, 
//                                            BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, 
//                                            NULL, NULL);
//            APP_ERROR_CHECK(err_code);
//            break;

//        case BLE_GATTS_EVT_SYS_ATTR_MISSING:
//            // No system attributes have been stored.
//            err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
//            APP_ERROR_CHECK(err_code);
//            break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            err_code = 
                sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                      BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            CONNECTION_MADE = false;
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            err_code = 
                sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                      BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            CONNECTION_MADE = false;
            APP_ERROR_CHECK(err_code);
            break;

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


/**@brief Function for the SoftDevice initialization.
 *
 * @details This function 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 initializing the Advertising functionality.
 */
static void advertising_init(void)
{
    uint32_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 = false;
    init.advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;

    init.srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.srdata.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 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)
{
    UNUSED_RETURN_VALUE(NRF_LOG_PROCESS());
    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);
    }
}


/* This function sets enable pin for ISFET circuitry to HIGH
 */
static inline void enable_analog_circuit(void)
{
    nrf_drv_gpiote_out_config_t config = NRFX_GPIOTE_CONFIG_OUT_SIMPLE(false);
    if(nrf_drv_gpiote_is_init() == false) {
          nrf_drv_gpiote_init();
    }
    nrf_drv_gpiote_out_init(ENABLE_ANALOG_PIN, &config);
    nrf_drv_gpiote_out_set(ENABLE_ANALOG_PIN);
}

/* This function sets enable pin for ISFET circuitry to LOW
 */
static inline void disable_analog_pin(void)
{
     // Redundant, but follows design
     nrfx_gpiote_uninit();
}

void timer_handler(nrf_timer_event_t event_type, void * p_context)
{
    // To Add Later
}


static inline void saadc_sampling_event_init(void)
{
    ret_code_t err_code;

    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
    timer_cfg.bit_width = NRF_TIMER_BIT_WIDTH_32;
    err_code = nrf_drv_timer_init(&m_timer, &timer_cfg, timer_handler);
    APP_ERROR_CHECK(err_code);

    /* setup m_timer for compare event every 15us */
    uint32_t ticks = nrf_drv_timer_us_to_ticks(&m_timer, 35);
    nrf_drv_timer_extended_compare(&m_timer,
                                   NRF_TIMER_CC_CHANNEL0,
                                   ticks,
                                   NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK,
                                   false);
    nrf_drv_timer_enable(&m_timer);

    uint32_t timer_compare_event_addr = 
                nrf_drv_timer_compare_event_address_get(&m_timer,
                                                        NRF_TIMER_CC_CHANNEL0);
    uint32_t saadc_sample_task_addr   = nrf_drv_saadc_sample_task_get();

    /* setup ppi channel so that timer compare event triggers task in SAADC */
    err_code = nrf_drv_ppi_channel_alloc(&m_ppi_channel);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_ppi_channel_assign(m_ppi_channel,
                                          timer_compare_event_addr,
                                          saadc_sample_task_addr);
    APP_ERROR_CHECK(err_code);
}


static inline void saadc_sampling_event_enable(void)
{
    ret_code_t err_code = nrf_drv_ppi_channel_enable(m_ppi_channel);
    APP_ERROR_CHECK(err_code);
}


/* Function for converting numbers > 9 to byte arrays in ASCII format
 * @params: Averaged value read from SAADC, ptr to byte array
 */
static inline void num_to_byte_arr(uint8_t *data_arr, uint32_t avg_val)
{
    uint8_t dig1, dig2, dig3;
    if(avg_val > 99) {
        dig1 = avg_val % 10;
        dig2 = ((avg_val % 100) - dig1) / 10;
        dig3 = (avg_val - (dig1 + (dig2 * 10))) / 100;
    
        // Convert to ASCII values
        data_arr[0] = dig3 + 48;
        data_arr[1] = dig2 + 48;
        data_arr[2] = dig1 + 48;
    }
    else if(avg_val > 9) {
        dig3 = 0;
        dig1 = avg_val % 10;
        dig2 = ((avg_val % 100) - dig1) / 10;

        // Convert to ASCII values
        data_arr[0] = dig2 + 48;
        data_arr[1] = dig1 + 48;
    }
    else {
        dig3 = 0;
        dig2 = 0;
        dig1 = avg_val;
        // Convert to ASCII value
        data_arr[0] = avg_val + 48;
    }
}

static inline void restart_saadc(void)
{
    nrfx_timer_uninit(&m_timer);
    nrfx_ppi_channel_free(m_ppi_channel);
    nrfx_saadc_uninit();
    while(nrfx_saadc_is_busy()) {
        // make sure SAADC is not busy
    }
    enable_pH_voltage_reading(); 
}

// Integers can have maximum 3 digits with 8-bit SAADC output
static inline int length_of_int(int x)
{
    if (x >= 100)        return 3;
    if (x >= 10)         return 2;
    return 1;
}

/* This function combines the ph_data and temp_data into one bluetooth
 * packet. The packet follows the format [ph_data,temp_data\n] where
 * data fields are between 1-3 bytes each (one per digit). 
 */
static inline uint8_t* format_bluetooth_packet(uint8_t*  ph_data,  
                                               uint8_t*  batt_data,    
                                               uint8_t*  temp_data,
                                               uint8_t*  total_packet, 
                                               uint16_t* total_size)
{
    num_to_byte_arr(temp_data, AVG_TEMP_VAL);
    num_to_byte_arr(batt_data, AVG_BATT_VAL);
    // Plus two for comma, plus one for EOL
    *total_size = length_of_int(AVG_PH_VAL) + length_of_int(AVG_TEMP_VAL) 
                                            + length_of_int(AVG_BATT_VAL) + 2 + 1;
    NRF_LOG_INFO("TOTAL SIZE: %d\n", *total_size);
    total_packet = (uint8_t*) malloc(sizeof(uint8_t) * (*total_size));
    // Copy pH data, copy temp data, add comma and EOL
    memcpy(total_packet, ph_data, length_of_int(AVG_PH_VAL));
    memcpy(total_packet + length_of_int(AVG_PH_VAL) + 1, 
                        temp_data, length_of_int(AVG_TEMP_VAL));
    memcpy(total_packet + length_of_int(AVG_PH_VAL) + 2 + length_of_int(AVG_TEMP_VAL), 
                        batt_data, length_of_int(AVG_BATT_VAL));
    total_packet[length_of_int(AVG_PH_VAL)] = 44; // comma
    total_packet[length_of_int(AVG_PH_VAL)+1+length_of_int(AVG_TEMP_VAL)] = 44; // comma
    total_packet[*total_size - 1] = 10; // EOL
    return total_packet;
}

static inline uint8_t* create_bluetooth_packet(uint32_t ph_val,
                                               uint32_t batt_val,        
                                               uint32_t temp_val, 
                                               uint8_t* total_packet,  
                                               uint16_t* total_size)
{
    uint8_t threedig_PH_data  [3] = {0, 0, 0};
    uint8_t threedig_BATT_data[3] = {0, 0, 0};
    uint8_t threedig_TEMP_data[3] = {0, 0, 0};
    uint8_t twodig_PH_data    [2] = {0, 0};
    uint8_t twodig_BATT_data  [2] = {0, 0};
    uint8_t twodig_TEMP_data  [2] = {0, 0};
    uint8_t onedig_PH_data    [1] = {0};
    uint8_t onedig_BATT_data  [1] = {0};
    uint8_t onedig_TEMP_data  [1] = {0};

    uint8_t* packet;

    if(AVG_PH_VAL > 99) {
        num_to_byte_arr(threedig_PH_data, AVG_PH_VAL);
        // Convert temp number to appropriate byte array
        if(AVG_TEMP_VAL > 99) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(threedig_PH_data, threedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(threedig_PH_data, twodig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(threedig_PH_data, onedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else if(AVG_TEMP_VAL > 9) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(threedig_PH_data, threedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(threedig_PH_data, twodig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(threedig_PH_data, onedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(threedig_PH_data, threedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(threedig_PH_data, twodig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(threedig_PH_data, onedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
        }
    }
    else if(AVG_PH_VAL > 9) {
        num_to_byte_arr(twodig_PH_data, AVG_PH_VAL);
        // Convert temp number to appropriate byte array
        if(AVG_TEMP_VAL > 99) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(twodig_PH_data, threedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(twodig_PH_data, twodig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(twodig_PH_data, onedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else if(AVG_TEMP_VAL > 9) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(twodig_PH_data, threedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(twodig_PH_data, twodig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(twodig_PH_data, onedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else 
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(twodig_PH_data, threedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(twodig_PH_data, twodig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(twodig_PH_data, onedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
    }
    else {
        num_to_byte_arr(onedig_PH_data, AVG_PH_VAL);
        // Convert temp number to appropriate byte array
        if(AVG_TEMP_VAL > 99) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(onedig_PH_data, threedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(onedig_PH_data, twodig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(onedig_PH_data, onedig_BATT_data, threedig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else if(AVG_TEMP_VAL > 9) {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(onedig_PH_data, threedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(onedig_PH_data, twodig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(onedig_PH_data, onedig_BATT_data, twodig_TEMP_data,
                                                                            total_packet, total_size);
        }
        else {
            if(AVG_BATT_VAL > 99)
                packet = format_bluetooth_packet(onedig_PH_data, threedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else if(AVG_BATT_VAL > 9)
                packet = format_bluetooth_packet(onedig_PH_data, twodig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
            else
                packet = format_bluetooth_packet(onedig_PH_data, onedig_BATT_data, onedig_TEMP_data,
                                                                            total_packet, total_size);
        }
    }
    return packet;    
}


/**
 * Function is called when SAADC reading event is done. First done event
 * reads pH input, stores in global variable. Second reading stores
 * pH data, combines pH and temp data into a comma-seperated string,
 * then transmits via BLE.
 *
 * BUG: p_buffer[0] is always '0' when reading pH at high frequency.
 *      Workaround is to average values besides 1, divide by 
 *      samples_in_buffer -1 .
 */
static inline void saadc_callback(nrf_drv_saadc_evt_t const * p_event)
{
    if (p_event->type == NRF_DRV_SAADC_EVT_DONE) 
    {
        ret_code_t err_code;
        uint16_t   total_size;
        uint32_t avg_saadc_reading = 0;
        // Byte array to store total packet
        uint8_t* total_packet;

        err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, 
                                                            SAMPLES_IN_BUFFER); 
        APP_ERROR_CHECK(err_code);
        // Sum and average SAADC values
        for (int i = 1; i < SAMPLES_IN_BUFFER; i++)
        {
            if (p_event->data.done.p_buffer[i] < 0) {
                avg_saadc_reading += 0;
            } 
            else {
                avg_saadc_reading += p_event->data.done.p_buffer[i];
            }
        }
        avg_saadc_reading = avg_saadc_reading/(SAMPLES_IN_BUFFER - 1); 
        // If ph has not been read, read it then restart SAADC to read temp
        if (!PH_IS_READ) {
            AVG_PH_VAL = avg_saadc_reading;
            PH_IS_READ = true;
            // Uninit saadc peripheral, restart saadc, enable sampling event
            NRF_LOG_INFO("read pH val, restarting: %d", AVG_PH_VAL);
            NRF_LOG_FLUSH();
            restart_saadc();
        } 
        // If pH has been read but not battery, read battery then restart
        else if (!(PH_IS_READ && BATTERY_IS_READ)) {
            AVG_BATT_VAL = avg_saadc_reading;
            NRF_LOG_INFO("read batt val, restarting: %d", AVG_BATT_VAL);
            NRF_LOG_FLUSH();
            BATTERY_IS_READ = true;
            restart_saadc();
        }
        // Once temp, batter and ph have been read, create and send data in packet
        else {
            AVG_TEMP_VAL = avg_saadc_reading;
            NRF_LOG_INFO("read temp val, restarting: %d", AVG_TEMP_VAL);
            NRF_LOG_FLUSH();
            // Convert pH number to appropriate byte array
            total_packet = create_bluetooth_packet((uint32_t)AVG_PH_VAL, 
                                                   (uint32_t)AVG_BATT_VAL,
                                                   (uint32_t)AVG_TEMP_VAL, 
                                                   total_packet, &total_size);
            // Send data
            err_code = ble_nus_data_send(&m_nus, total_packet, 
                                         &total_size, m_conn_handle);
            // reset global control boolean
            PH_IS_READ = false;
            BATTERY_IS_READ = false;
            // Free dynamic array
            free(total_packet);
            // Turn off peripherals
            NRF_LOG_INFO("BLUETOOTH DATA SENT\n");
            NRF_LOG_FLUSH();
            disable_pH_voltage_reading();
 
            NRF_LOG_INFO("SAADC DISABLED\n");
            NRF_LOG_FLUSH();
        }
    }
}


/* Reads pH transducer output
 */
void saadc_init(void)
{
    ret_code_t err_code;
    nrf_saadc_input_t ANALOG_INPUT;
    // Change pin depending on global control boolean
    if (!PH_IS_READ) {
        NRF_LOG_INFO("Setting saadc input to AIN1\n");
        ANALOG_INPUT = NRF_SAADC_INPUT_AIN1;
    }
    else if (!(PH_IS_READ && BATTERY_IS_READ)) {
        NRF_LOG_INFO("Setting saadc input to AIN3\n");
        ANALOG_INPUT = NRF_SAADC_INPUT_AIN3;
    }
    else {
        NRF_LOG_INFO("Setting saadc input to AIN0\n");
        ANALOG_INPUT = NRF_SAADC_INPUT_AIN0;        
    }

    nrf_saadc_channel_config_t channel_config =
            NRF_SAADC_CUSTOM_CHANNEL_CONFIG_SE(ANALOG_INPUT);

    err_code = nrf_drv_saadc_init(NULL, saadc_callback);
    APP_ERROR_CHECK(err_code);

    /*
     * BUG: calibration never completes
     */

    // Calibrate offset
    // if(!SAADC_CALIBRATED) {
    //     while (nrfx_saadc_calibrate_offset() != NRFX_SUCCESS) {
    //         NRF_LOG_INFO("calibration does not equal success\n");
    //         NRF_LOG_FLUSH();
    //         nrf_delay_us(10);
    //     }
    //     SAADC_CALIBRATED = true;
    //     while (nrfx_saadc_is_busy()) {
    //         NRF_LOG_INFO("saadc busy while restarting\n");
    //         NRF_LOG_FLUSH();
    //         nrf_delay_ms(1000);
    //     }
    // }   

    err_code = nrf_drv_saadc_channel_init(0, &channel_config);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_buffer_convert(m_buffer_pool[0], SAMPLES_IN_BUFFER);
    APP_ERROR_CHECK(err_code);
}


/* This function initializes and enables SAADC sampling
 */
static inline void enable_pH_voltage_reading(void)
{
    saadc_init();
    saadc_sampling_event_init();
    saadc_sampling_event_enable();
    nrf_pwr_mgmt_run();
}

/* Function unitializes and disables SAADC sampling, restarts 1 second timer
 */
static inline void disable_pH_voltage_reading(void)
{
    nrfx_timer_uninit(&m_timer);
    nrfx_ppi_channel_free(m_ppi_channel);
    nrfx_saadc_uninit();

    // *** DISABLE ENABLE ***
    disable_analog_pin();

    // Restart timer
    ret_code_t err_code;
    err_code = app_timer_start(m_timer_id, APP_TIMER_TICKS(1500), NULL);
    APP_ERROR_CHECK(err_code);
    nrf_pwr_mgmt_run();

    NRF_LOG_INFO("TIMER RESTARTED (disable_ph_voltage_reading)\n");
    NRF_LOG_FLUSH();
}

static inline void single_shot_timer_handler()
{
    // disable timer
    ret_code_t err_code;
    err_code = app_timer_stop(m_timer_id);

    // Delay to ensure appropriate timing between
    enable_analog_circuit();       
    // PWM output, ISFET capacitor, etc
    nrf_delay_us(2000);              
    // Begin SAADC initialization/start
    enable_pH_voltage_reading();
}

/**@brief Function for handling events from the GATT library. */
void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
{
    if ((m_conn_handle == p_evt->conn_handle) && 
        (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED))
    {
        m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH 
                                                                 - HANDLE_LENGTH;

        ret_code_t err_code;

         // Create application timer
        err_code = app_timer_create(&m_timer_id,
                                    APP_TIMER_MODE_SINGLE_SHOT,
                                    single_shot_timer_handler);
        APP_ERROR_CHECK(err_code);
        
        // 1 second timer intervals
        err_code = app_timer_start(m_timer_id, APP_TIMER_TICKS(2000), NULL);
        APP_ERROR_CHECK(err_code);

        NRF_LOG_INFO("TIMER STARTED (gatt_evt_handler) \n");
        NRF_LOG_FLUSH();

        nrf_pwr_mgmt_run();
    }
    NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
                  p_gatt->att_mtu_desired_central,
                  p_gatt->att_mtu_desired_periph);
}

/**@brief Function for initializing the GATT library. */
void gatt_init(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, 
                                               NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
}

/**@brief Application main function.
 */
int main(void)
{
    bool erase_bonds = false;

    log_init();
    timers_init();
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();
    peer_manager_init();
    // Initial pin state is low
    disable_analog_pin();
    advertising_start(erase_bonds);
    // Enter main loop.
    while (true)
    {
        idle_state_handle();
    } 
}

/*
 * @}
 */

Parents
  • Hi,

    I do not see anything wrong with how you are using the peer manager. It seems copy-pasted from other SDK examples, with the only modification that you have added some logging in your pm_evt_handler(). There is nothing missing in your main.c or sdk_config.h related to the peer manger as far as I can see.

    You write that the behavior changed without you modifying the code at all. Obviously something has changed. Are you sure this is the code you are testing, or could there be a mixup of some sort? Do you still have problems if you do a full erase of the nRF device (nrfjprog -e) before you program it and delete the bond on the iOS device and try again? I ask because the error you get 4102 = 0x1006 = PM_CONN_SEC_ERROR_PIN_OR_KEY_MISSING to indicate to me that you have lost bonding information on just one side.

    Note that you can allow repairing if you don't want this to happen again, and are OK with the security implications of it. If so, just add handling of the PM_EVT_CONN_SEC_CONFIG_REQ event to you peer manager event handler:

            case PM_EVT_CONN_SEC_CONFIG_REQ:
            {
                // Allow pairing request from an already bonded peer.
                pm_conn_sec_config_t conn_sec_config = {.allow_repairing = true};
                pm_conn_sec_config_reply(p_evt->conn_handle, &conn_sec_config);
            } break;

Reply
  • Hi,

    I do not see anything wrong with how you are using the peer manager. It seems copy-pasted from other SDK examples, with the only modification that you have added some logging in your pm_evt_handler(). There is nothing missing in your main.c or sdk_config.h related to the peer manger as far as I can see.

    You write that the behavior changed without you modifying the code at all. Obviously something has changed. Are you sure this is the code you are testing, or could there be a mixup of some sort? Do you still have problems if you do a full erase of the nRF device (nrfjprog -e) before you program it and delete the bond on the iOS device and try again? I ask because the error you get 4102 = 0x1006 = PM_CONN_SEC_ERROR_PIN_OR_KEY_MISSING to indicate to me that you have lost bonding information on just one side.

    Note that you can allow repairing if you don't want this to happen again, and are OK with the security implications of it. If so, just add handling of the PM_EVT_CONN_SEC_CONFIG_REQ event to you peer manager event handler:

            case PM_EVT_CONN_SEC_CONFIG_REQ:
            {
                // Allow pairing request from an already bonded peer.
                pm_conn_sec_config_t conn_sec_config = {.allow_repairing = true};
                pm_conn_sec_config_reply(p_evt->conn_handle, &conn_sec_config);
            } break;

Children
  • I began experiencing this issue after I deleted bonding information from my iOS device. Now I don't get any debug logs from any peer manager functions. I have tried erasing the DK through Segger Embedded Studios and reflashing, but this does not seem to make a difference. I have also tried with three different phones which were never previously bonded, and tried with two new DKs that I had never flashed this code onto. I don't see the error anymore, or any logs involved to peer manager anymore. 

  • This is what I see in my debug terminal now, whereas previously I would see logs I put in the peer manager handler as well as logs from the default pm_evt_handler_log function logs (where the error/success would be written)

  • Hi,

    Noah said:
    I have tried erasing the DK through Segger Embedded Studios and reflashing

    How did you do it? SES normally just does a sector erase, and in that case, the FDS pages holding the bonding information is left untouched. This is then still valid after you program the application again. So to fix this, either completely erase the chip using "nrfjprog -e" or explicitly allow repairing as I explained in my previous post.

  • I tried fully erasing the DK using nrfjprog -e, and I also explicitly allowed pairing with the example code you provided. I also added another case into pm_evt_handler for "PM_EVT_SEC_SUCCEEDED" in which I simply output text using NRF_LOG_INFO(). However, the behavior still persists and the pm_evt_handler function is never called or entered at all. I even deleted all the peer manager related functions, and re-integrated them from the ble_app_template example. I also checked through the heart rate sensor example and verified I'm using the same function calls/configurations/etc, the heart rate sensor example is almost the same as the ble_app_template with regards to bonding. Also did this for ble_app_bps example.

    When should events be passed to the Peer Manager, and how are they passed? The peer manager is not referenced or mentioned in any other functions. Variable "ble_gap_sec_params_t sec_param" is set inside peer_manager_init(), but how does this function relate to the rest of the program? I know that in older SDK versions, a function called "ble_evt_dispatch" would dispatch events to the peer manager. This is even discussed in a comment within main.c of ble_app_bps example, line 215-217. The comment reads:

    "NOTE: For this to work, make sure ble_bps_on_ble_evt() is called before ble_bondmngr_on_ble_evt() in ble_evt_dispatch()"

    However there are no such functions in any examples within SDK version 15.2.0. 

  • Hi,

    You have described two distinctly different issues:

    • The issue where you deleted bonding information on one side and got error 4102, is caused by only deleting bonding information on the phone, and not the device, as explained in my last two posts.
    • Regarding the issue with no peer manger events:
      • There is no need to pass the event to the peer manager from your application like it was done in older SDK versions. This is because in 15.2, this is handled by the peer manager itself. (Specifically, you can see that peer_manager.c uses the NRF_SDH_BLE_OBSERVER to register it's event handler so that the SoftDevice Handler library forwards the events directly.)
      • I suspect that the phone simply never attempts to pair or bond? Have you double-checked that? iOS will only pair/bond when needed because it attempts to access a characteristic that requires that. Therefore, I suggest you test with Android or nRF Connect for Dekstop first (if you have an additional nRF52 DK or dongle) to see if it works, since there you can manually trigger pairing.
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