RE: I am facing error code 4 : transaction not scheduled repeatedly while using nrf_twi_sensor_reg_read function in my private function

Sqngmin — Wed, 09 Oct 2019 13:41:08 GMT
I think I should show you all of my code
/**
 * Copyright (c) 2014 - 2019, Nordic Semiconductor ASA
 *
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 *
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 *    such product, must reproduce the above copyright notice, this list of
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 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
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 */
/** @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 <stdbool.h>
#include <stdio.h>

#include <stdint.h>
#include <string.h>
#include "nordic_common.h"
#include "nrf.h"
#include "ble_hci.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"
#include "nrf_sdh.h"

      #include "nrf_drv_twi.h"
      #include "nrf_drv_clock.h"
      #include "compiler_abstraction.h"
      #include "nrf_twi_sensor.h"
      #include "nrf_twi_mngr.h"
      #include "nrf_twi.h"
      #include "nrf_delay.h"
      #include "reg.h"

#include "nrf_sdh_soc.h"
#include "nrf_sdh_ble.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_qwr.h"
#include "app_timer.h"
#include "ble_nus.h"
#include "app_uart.h"
#include "app_util_platform.h"
#include "bsp_btn_ble.h"
#include "nrf_pwr_mgmt.h"

#include "nrf_delay.h"

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

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "nrf_drv_saadc.h"
#include "nrf_drv_ppi.h"
#include "nrf_drv_timer.h"
#include "boards.h"
#include "app_error.h"
#include "app_util.h"

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

#define DEVICE_NAME                     "Nordic_Blinky"                               /**< 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                64                                          /**< The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */

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

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(100, UNIT_1_25_MS)             /**< Minimum acceptable connection interval (20 ms), Connection interval uses 1.25 ms units. */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(200, 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(20000)                       /**< 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(5000)                      /**< 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 BYTES 6
      #define II_ADDR (0x33U >>1)
      #define MAX_PENDING_TRANSACTIONS    6


#define FLAME_PIN NRF_SAADC_INPUT_AIN0
#define SOUND_PIN NRF_SAADC_INPUT_AIN1
#define HUMID_PIN NRF_SAADC_INPUT_AIN2
#define BAT_PIN NRF_SAADC_INPUT_VDD

#define FLAME_CHANNEL 0
#define SOUND_CHANNEL 1
#define HUMID_CHANNEL 2
#define BAT_CHANNEL 3

#define ADC_REF_VOLTAGE_IN_MILLIVOLTS   600                                     /**< Reference voltage (in milli volts) used by ADC while doing conversion. */
#define ADC_PRE_SCALING_COMPENSATION    6                                       /**< The ADC is configured to use VDD with 1/3 prescaling as input. And hence the result of conversion is to be multiplied by 3 to get the actual value of the battery voltage.*/
#define DIODE_FWD_VOLT_DROP_MILLIVOLTS  270                                     /**< Typical forward voltage drop of the diode . */
#define ADC_RES_10BIT                   1024                                    /**< Maximum digital value for 10-bit ADC conversion. */

#define ADC_RESULT_IN_MILLI_VOLTS(ADC_VALUE)\
        ((((ADC_VALUE) * ADC_REF_VOLTAGE_IN_MILLIVOLTS) / ADC_RES_10BIT) * ADC_PRE_SCALING_COMPENSATION)

static nrf_saadc_channel_config_t ch_config_flame = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(FLAME_PIN);
static nrf_saadc_channel_config_t ch_config_sound = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(SOUND_PIN);
static nrf_saadc_channel_config_t ch_config_humid = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(HUMID_PIN);
static nrf_saadc_channel_config_t ch_config_bat = NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(BAT_PIN);

static const nrf_drv_timer_t m_timer = NRF_DRV_TIMER_INSTANCE(2);
      APP_TIMER_DEF(m_timer_II);
      static const nrf_drv_twi_t m_twi = NRF_DRV_TWI_INSTANCE(0);

static nrf_saadc_value_t m_buffer_pool[4];

static nrf_saadc_value_t flame_raw, sound_raw, humid_raw, bat_raw;

static nrf_ppi_channel_t     m_ppi_channel;
static uint32_t              m_adc_evt_counter;
      static uint32_t              m_twi_evt_counter;

      static axis3bit16_t          data_raw_acceleration[3];
      static iis2dlpc_ctx_t        dev_ctx;
      static uint8_t               whoamI, rst;
      static float acceleration_mg[3];
      static int SIZE;
      static int current_value[3];
      static int previous_value[3] = {0};
      static char difference0[3]; // X
      static char difference1[3]; // Y
      static char difference2[3]; // Z
      static char m_buffer[9];

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);  
      NRF_TWI_MNGR_DEF(m_nrf_twi_mngr, MAX_PENDING_TRANSACTIONS, 0);
      NRF_TWI_SENSOR_DEF(m_nrf_twi_sensor, &m_nrf_twi_mngr, NRF_TWI_SENSOR_SEND_BUF_SIZE);
                                               /**< Advertising module instance. */

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}
//};

static ble_uuid_t m_adv_uuids[] =                                               /**< Universally unique service identifiers. */
{
    {BLE_UUID_DEVICE_INFORMATION_SERVICE, BLE_UUID_TYPE_BLE}
};

/**@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 initializing the timer module.
 */
static void timers_init(void)
{
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
}

static void lfclk_config(void)
{
    uint32_t err_code;

    err_code = nrf_drv_clock_init();
    APP_ERROR_CHECK(err_code);

    nrf_drv_clock_lfclk_request(NULL);
}
/**@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 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);

    sd_ble_gap_appearance_set(BLE_APPEARANCE_HID_KEYBOARD);

    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 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 = bsp_indication_set(BSP_INDICATE_IDLE);
    APP_ERROR_CHECK(err_code);

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

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


/**@brief Function for handling advertising events.
 *
 * @details This function will be called for advertising events which are passed to the application.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
    uint32_t err_code;

    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
            err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
            APP_ERROR_CHECK(err_code);
            break;
        case BLE_ADV_EVT_IDLE:
            sleep_mode_enter();
            break;
        default:
            break;
    }
}

/**@brief Function for starting advertising.
 */
static void advertising_start(void)
{
    uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
    APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    uint32_t err_code;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO("Connected");
            err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
            APP_ERROR_CHECK(err_code);
            m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
            err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected");
            err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
            APP_ERROR_CHECK(err_code);
            // LED indication will be changed when advertising starts.
            m_conn_handle = BLE_CONN_HANDLE_INVALID;
            advertising_start();
            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);
            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);
            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 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;
        NRF_LOG_INFO("Data len is set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
    }
    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 Function for handling events from the BSP module.
 *
 * @param[in]   event   Event generated by button press.
 */
void bsp_event_handler(bsp_event_t event)
{
    uint32_t err_code;
    switch (event)
    {
        case BSP_EVENT_SLEEP:
            sleep_mode_enter();
            break;

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

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

        default:
            break;
    }
}


/**@brief   Function for handling app_uart events.
 *
 * @details This function will receive a single character from the app_uart module and append it to
 *          a string. The string will be be sent over BLE when the last character received was a
 *          'new line' '\n' (hex 0x0A) or if the string has reached the maximum data length.
 */
/**@snippet [Handling the data received over UART] */
void uart_event_handle(app_uart_evt_t * p_event)
{
    static uint8_t data_array[10] = {0x70,0x5A,0x25,'\r','\n'};
    static uint8_t index= 6;

    //static uint8_t index = 0;
    uint32_t       err_code;

    uint16_t length = (uint16_t)index;
    uint32_t delaytime = 1000;
    ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
    nrf_delay_ms(delaytime);
}
/**@snippet [Handling the data received over UART] */

/**@brief  Function for initializing the UART module.
 */
/**@snippet [UART Initialization] */
static void uart_init(void)
{
    uint32_t                     err_code;
    app_uart_comm_params_t const comm_params =
    {
        .rx_pin_no    = RX_PIN_NUMBER,
        .tx_pin_no    = TX_PIN_NUMBER,
        .rts_pin_no   = RTS_PIN_NUMBER,
        .cts_pin_no   = CTS_PIN_NUMBER,
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UART_BAUDRATE_115200
#else
        .baud_rate    = NRF_UARTE_BAUDRATE_115200
#endif
    };

    APP_UART_FIFO_INIT(&comm_params,
                       UART_RX_BUF_SIZE,
                       UART_TX_BUF_SIZE,
                       uart_event_handle,
                       APP_IRQ_PRIORITY_LOWEST,
                       err_code);
    APP_ERROR_CHECK(err_code);
}
/**@snippet [UART Initialization] */


/**@brief Function for initializing the Advertising functionality.
 */
static void advertising_init(void)
{
    ret_code_t  err_code;
    ble_advertising_init_t init;
    memset(&init, 0, sizeof(init));

    uint8_t data[] = "SomeData!";

    ble_advdata_manuf_data_t manuf_data;
    manuf_data.company_identifier = 0x0059;
    manuf_data.data.p_data = data;
    manuf_data.data.size = sizeof(data);
    init.advdata.p_manuf_specific_data = &manuf_data;

    init.advdata.name_type          = BLE_ADVDATA_SHORT_NAME;
    init.advdata.short_name_len     = true;
    init.advdata.include_appearance = true;
    init.advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_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;
    int8_t tx_power_level = -4;
    init.advdata.p_tx_power_level = &tx_power_level;

    ble_advdata_manuf_data_t manuf_data_response;
    uint8_t data_response[]="Many_bytes_of_data";
    manuf_data_response.company_identifier=0x0059;
    manuf_data_response.data.p_data=data_response;
    manuf_data_response.data.size=sizeof(data_response);
    init.srdata.name_type = BLE_ADVDATA_NO_NAME;
    init.srdata.p_manuf_specific_data=&manuf_data_response;

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

    init.evt_handler = on_adv_evt;

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

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}


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

    uint32_t err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
    APP_ERROR_CHECK(err_code);

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

    *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}


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

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


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



/**@brief Application main function.
 */
void timer_handler(nrf_timer_event_t event_type, void * p_context)
{

}


void saadc_sampling_event_init(void)
{
    ret_code_t err_code;

    err_code = nrf_drv_ppi_init();
    APP_ERROR_CHECK(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 400ms */
    uint32_t ticks = nrf_drv_timer_ms_to_ticks(&m_timer, 400);
    nrf_drv_timer_extended_compare(&m_timer,
                                   NRF_TIMER_CC_CHANNEL2,
                                   ticks,
                                   NRF_TIMER_SHORT_COMPARE2_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_CHANNEL2);
    uint32_t saadc_sample_task_addr   = nrf_drv_saadc_sample_task_get();


    /* setup ppi channel so that timer compare event is triggering sample 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);
}

void saadc_sampling_event_enable(void)
{
    ret_code_t err_code = nrf_drv_ppi_channel_enable(m_ppi_channel);

    APP_ERROR_CHECK(err_code);
}


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;
        nrf_saadc_value_t bat_result;
        uint16_t          batt_lvl_in_milli_volts;
        uint8_t           percentage_batt_lvl;
        char  temp[20];
        static uint8_t data_array[20];
        uint8_t temp2;

        err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, sizeof(m_buffer_pool)/sizeof(nrf_saadc_value_t));
        APP_ERROR_CHECK(err_code);

        int i;
        NRF_LOG_INFO("ADC event number: %d", (int)m_adc_evt_counter);

        m_adc_evt_counter++;

        bat_result = p_event->data.done.p_buffer[BAT_CHANNEL];

        batt_lvl_in_milli_volts = ADC_RESULT_IN_MILLI_VOLTS(bat_result) +
                                  DIODE_FWD_VOLT_DROP_MILLIVOLTS;
        percentage_batt_lvl = battery_level_in_percent(batt_lvl_in_milli_volts);

        sprintf(temp, "%X %X %X %X", p_event->data.done.p_buffer[FLAME_CHANNEL], p_event->data.done.p_buffer[SOUND_CHANNEL], p_event->data.done.p_buffer[HUMID_CHANNEL], percentage_batt_lvl);
        printf("%s\n", temp);
   }
}

void saadc_init(void)
{
    ret_code_t err_code;

    ch_config_flame.gain = NRF_SAADC_GAIN1;
    ch_config_sound.gain = NRF_SAADC_GAIN1;
    ch_config_humid.gain = NRF_SAADC_GAIN1;
    ch_config_bat.gain = NRF_SAADC_GAIN1_4;


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

    err_code = nrf_drv_saadc_channel_init(FLAME_CHANNEL, &ch_config_flame);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_channel_init(SOUND_CHANNEL, &ch_config_sound);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_channel_init(HUMID_CHANNEL, &ch_config_humid);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_saadc_channel_init(BAT_CHANNEL, &ch_config_bat);
    APP_ERROR_CHECK(err_code);

    err_code = nrfx_saadc_buffer_convert(m_buffer_pool, sizeof(m_buffer_pool)/sizeof(nrf_saadc_value_t));
    APP_ERROR_CHECK(err_code);

    nrfx_saadc_sample();
}





static int32_t platform_read(void *handle, uint8_t reg, uint8_t *bufp, uint16_t len)
{
  nrf_twi_sensor_reg_read(&m_nrf_twi_sensor, II_ADDR, reg, NULL, bufp, len);
  NRF_LOG_INFO("TWI event number: %d", (int)m_twi_evt_counter);
  m_twi_evt_counter++;
  return 0;
}


static int32_t platform_write(void *handle, uint8_t reg, uint8_t *bufp, uint16_t len)
{
  nrf_twi_sensor_reg_write(&m_nrf_twi_sensor, II_ADDR, reg, bufp, len);  
  NRF_LOG_INFO("TWI event number: %d", (int)m_twi_evt_counter);
  m_twi_evt_counter++;
  return 0;
}

static void twi_init(void)
{
    uint32_t err_code;
    dev_ctx.write_reg = platform_write;
    dev_ctx.read_reg = platform_read;
    dev_ctx.handle = NULL;

    const nrf_drv_twi_config_t ii_config = {
       .scl                = ARDUINO_SCL_PIN,
       .sda                = ARDUINO_SDA_PIN,
       .frequency          = NRF_DRV_TWI_FREQ_100K,
       .interrupt_priority = APP_IRQ_PRIORITY_LOWEST,
       .clear_bus_init     = false
    };

    err_code = nrf_twi_mngr_init(&m_nrf_twi_mngr, &ii_config);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_twi_sensor_init(&m_nrf_twi_sensor);
    APP_ERROR_CHECK(err_code);
}

char* dto62(int decimal)
{
static char hexabindecimal[20] = {0, };
static char minus_hexabindecimal[20];
int position = 0;
int minus_flag = 0;
    while (1)
        {
          if(decimal<0)
            {
             minus_flag=1;
             decimal=decimal*-1;
            }
            int mod = decimal % 62; 
            if (mod < 10)
            {
               hexabindecimal[position] = 48 + mod;
            }
            else if(mod < 36)
            {
               hexabindecimal[position] = 65 + (mod - 10);
            }
            else
            {
               hexabindecimal[position] = 97 + (mod - 36);
            }

            decimal = decimal / 62;

            position++;

            if (decimal == 0)
                break;
        }

  reverseString(hexabindecimal);

  if(minus_flag==1)
  {
    sprintf(minus_hexabindecimal,"-%s",hexabindecimal);
    return minus_hexabindecimal;
  }
  return hexabindecimal;
}
/*
void iirun(void)
{  
    memset(data_raw_acceleration[0].u8bit, 0x00, 3 * sizeof(int16_t));
    memset(data_raw_acceleration[1].u8bit, 0x00, 3 * sizeof(int16_t));
    memset(data_raw_acceleration[2].u8bit, 0x00, 3 * sizeof(int16_t));
	  
    iis2dlpc_acceleration_raw_get(&dev_ctx, data_raw_acceleration[0].u8bit);
    iis2dlpc_acceleration_rawY_get(&dev_ctx, data_raw_acceleration[1].u8bit);
    iis2dlpc_acceleration_rawZ_get(&dev_ctx, data_raw_acceleration[2].u8bit);
	  	  
    acceleration_mg[0] = iis2dlpc_from_fs16_lp1_to_mg(data_raw_acceleration[0].i16bit[0]);
    acceleration_mg[1] = iis2dlpc_from_fs16_lp1_to_mg(data_raw_acceleration[1].i16bit[0]);
    acceleration_mg[2] = iis2dlpc_from_fs16_lp1_to_mg(data_raw_acceleration[2].i16bit[0]);
    
	current_value[0] = (int)(acceleration_mg[0]);
	current_value[1] = (int)(acceleration_mg[1]);
	current_value[2] = (int)(acceleration_mg[2]);

        strcpy(difference0,dto62(current_value[0]-previous_value[0]));
        strcpy(difference1,dto62(current_value[1]-previous_value[1]));
        strcpy(difference2,dto62(current_value[2]-previous_value[2]));
        sprintf(m_buffer, "%s %s %s", difference0, difference1, difference2);
        printf("%s\r\n",m_buffer);
  
  for(int i=0; i<3; i++)
  {
    previous_value[i] = current_value[i];
  }

}
*/

void timer_handler_II(void * p_context)
{
//    iirun();
  uint8_t reg_init;

  iis2dlpc_flag_data_ready_get(&dev_ctx, &reg_init);
  if(reg_init)
  {
    memset(data_raw_acceleration[0].u8bit, 0x00, 3 * sizeof(int16_t));
    memset(data_raw_acceleration[1].u8bit, 0x00, 3 * sizeof(int16_t));
    memset(data_raw_acceleration[2].u8bit, 0x00, 3 * sizeof(int16_t));
	  
//    iis2dlpc_read_reg(ctx, IIS2DLPC_OUT_X_L, buff, 6);
//    iis2dlpc_read_reg(ctx, IIS2DLPC_OUT_Y_L, buff, 6);
//    iis2dlpc_read_reg(ctx, IIS2DLPC_OUT_Z_L, buff, 6);

    iis2dlpc_acceleration_raw_get(&dev_ctx, data_raw_acceleration[0].u8bit);
    iis2dlpc_acceleration_rawY_get(&dev_ctx, data_raw_acceleration[1].u8bit);
    iis2dlpc_acceleration_rawZ_get(&dev_ctx, data_raw_acceleration[2].u8bit);
	  	  
    acceleration_mg[0] = iis2dlpc_from_fs16_lp1_to_mg(data_raw_acceleration[0].i16bit[0]);
    acceleration_mg[1] = iis2dlpc_from_fs16_lp1_to_mg(data_raw_acceleration[1].i16bit[0]);
    acceleration_mg[2] = iis2dlpc_from_fs16_lp1_to_mg(data_raw_acceleration[2].i16bit[0]);
    
	current_value[0] = (int)(acceleration_mg[0]);
	current_value[1] = (int)(acceleration_mg[1]);
	current_value[2] = (int)(acceleration_mg[2]);

        strcpy(difference0,dto62(current_value[0]-previous_value[0]));
        strcpy(difference1,dto62(current_value[1]-previous_value[1]));
        strcpy(difference2,dto62(current_value[2]-previous_value[2]));
        sprintf(m_buffer, "%s %s %s", difference0, difference1, difference2);
        printf("%s\r\n",m_buffer);
  }
  else
  {
  printf("can't read reg data\r\n");
  }
  for(int i=0; i<3; i++)
  {
    previous_value[i] = current_value[i];
  }
}



 void platform_init(void)
{
  ret_code_t err_code;

  iis2dlpc_device_id_get(&dev_ctx, &whoamI);
//  do {
//    if(whoamI != IIS2DLPC_ID){
//      printf("\r\ndevice_id_get failed\r\n");
//      }
//    nrf_delay_ms(400);
//    iis2dlpc_device_id_get(&dev_ctx, &whoamI);
//  } while(whoamI != IIS2DLPC_ID);
  iis2dlpc_reset_set(&dev_ctx, PROPERTY_ENABLE);
  do {
    iis2dlpc_reset_get(&dev_ctx, &rst);
  } while (rst);
  iis2dlpc_block_data_update_set(&dev_ctx, PROPERTY_ENABLE);
  iis2dlpc_full_scale_set(&dev_ctx, IIS2DLPC_16g);
  iis2dlpc_filter_path_set(&dev_ctx, IIS2DLPC_LPF_ON_OUT);
  iis2dlpc_filter_bandwidth_set(&dev_ctx, IIS2DLPC_ODR_DIV_10);
  iis2dlpc_power_mode_set(&dev_ctx, IIS2DLPC_HIGH_PERFORMANCE_LOW_NOISE);
  iis2dlpc_data_rate_set(&dev_ctx, IIS2DLPC_XL_ODR_100Hz);
  printf("\r\nall settings are completed\r\n");

  err_code = app_timer_create(&m_timer_II, APP_TIMER_MODE_REPEATED, timer_handler_II);
  APP_ERROR_CHECK(err_code);

  err_code = app_timer_start(m_timer_II, APP_TIMER_TICKS(400), NULL);
  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.
 */
void idle_state_handle(void)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}


int main(void)
{
    bool erase_bonds;

    // Initialize.
    log_init();
    lfclk_config();
    timers_init();
    uart_init();
    twi_init();
    buttons_leds_init(&erase_bonds);
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();

//    twi_sensor_init(); //*
    platform_init();

//    advertising_init(); //*
    services_init();
    advertising_init();
    conn_params_init();
//    peer_manger_init(); //*
    saadc_init();
    saadc_sampling_event_init();
    saadc_sampling_event_enable();    
   
    // Start execution.
    printf("\r\nUART started.\r\n");
    NRF_LOG_INFO("Debug logging for UART over RTT started.");
    advertising_start();

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


/**
 * @}
 */
and you can get reference of reg.c, reg.h in below url
https://github.com/STMicroelectronics/STMems_Standard_C_drivers/blob/master/iis2dlpc_STdC/driver/iis2dlpc_reg.h
I coded platform_read/write/init function with example of below url
https://github.com/STMicroelectronics/STMems_Standard_C_drivers/blob/master/iis2dlpc_STdC/example/read_data_simple.c