<?xml version="1.0" encoding="UTF-8" ?>
<?xml-stylesheet type="text/xsl" href="https://devzone.nordicsemi.com/cfs-file/__key/system/syndication/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>BLE_APP_UART does not work when add twi_sensor</title><link>https://devzone.nordicsemi.com/f/nordic-q-a/110907/ble_app_uart-does-not-work-when-add-twi_sensor</link><description>Hello everyone, currently I am writing a program to read the SCD41(I2C) sensor and then use BLE to transmit information. With a separate program in twi_sensor, I see that the sensor is working, then I add the necessary files and edit a few files like</description><dc:language>en-US</dc:language><generator>Telligent Community 13</generator><lastBuildDate>Fri, 24 May 2024 11:33:09 GMT</lastBuildDate><atom:link rel="self" type="application/rss+xml" href="https://devzone.nordicsemi.com/f/nordic-q-a/110907/ble_app_uart-does-not-work-when-add-twi_sensor" /><item><title>RE: BLE_APP_UART does not work when add twi_sensor</title><link>https://devzone.nordicsemi.com/thread/485795?ContentTypeID=1</link><pubDate>Fri, 24 May 2024 11:33:09 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:8f77b1de-eae2-406f-b2c1-6817d8bcc6e2</guid><dc:creator>Simonr</dc:creator><description>&lt;p&gt;Hi&lt;/p&gt;
&lt;p&gt;Jonathan asked me if I could take a look at this case as he&amp;#39;s busy with a few other things. Your logging here seems to be returning error message 3.&amp;nbsp;I&amp;#39;m not able to find what this error message regturns, but if you&amp;#39;re using the nRF driver errors from nrf_error.h in the nRF5 SDK, it is an internal error. What pins on the nRF52840 are you using for serial here, as incorrect pin configs I think could result in this internal error.&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Simon&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: BLE_APP_UART does not work when add twi_sensor</title><link>https://devzone.nordicsemi.com/thread/485683?ContentTypeID=1</link><pubDate>Thu, 23 May 2024 15:48:34 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:b2e4beda-4ece-40c9-a639-8ac1d03c66b0</guid><dc:creator>Dat Nguyen</dc:creator><description>&lt;p&gt;&lt;img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1716478868601v1.png" alt=" " /&gt;&lt;br /&gt;&lt;img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1716479063444v2.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;I discovered an error in the line printf(&amp;quot;Error executing scd4x_get_serial_number(): %i\n&amp;quot;, error);&lt;br /&gt;According to what I do in the twi_sensor section, it will need to jump to the &amp;quot;else&amp;quot; section, but I don&amp;#39;t understand the reason why it jumps to the &amp;quot;if&amp;quot; line.&lt;br /&gt;This is my library for SCD41: &lt;a href="https://github.com/Sensirion/embedded-i2c-scd4x/tree/master"&gt;github.com/.../master&lt;/a&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: BLE_APP_UART does not work when add twi_sensor</title><link>https://devzone.nordicsemi.com/thread/485371?ContentTypeID=1</link><pubDate>Wed, 22 May 2024 11:08:56 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:2fc41fe3-4959-43cd-935c-f3c752ff7ec7</guid><dc:creator>JONATHAN LL</dc:creator><description>&lt;p&gt;I am not able se the issue from what you share.&amp;nbsp;&lt;br /&gt;&lt;br /&gt;You should try to remove on thing at the time untill it works again and see what is causing it to fail.&amp;nbsp;&lt;br /&gt;&lt;br /&gt;Regards,&lt;br /&gt;Jonathan&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: BLE_APP_UART does not work when add twi_sensor</title><link>https://devzone.nordicsemi.com/thread/484860?ContentTypeID=1</link><pubDate>Sat, 18 May 2024 08:48:48 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:a62ef72d-5102-4859-aadf-1e55b018ce0c</guid><dc:creator>Dat Nguyen</dc:creator><description>&lt;p&gt;I still haven&amp;#39;t solved the problem&lt;/p&gt;
&lt;p&gt;This is sensor parameters&lt;br /&gt;&lt;img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1716022001901v1.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;But when i debug, it just show like that&lt;br /&gt;&lt;img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1716022123762v2.png" alt=" " /&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: BLE_APP_UART does not work when add twi_sensor</title><link>https://devzone.nordicsemi.com/thread/483399?ContentTypeID=1</link><pubDate>Wed, 15 May 2024 07:16:32 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:ca93c79b-00b3-4ba3-8e2f-c2affd14705f</guid><dc:creator>JONATHAN LL</dc:creator><description>&lt;p&gt;Sorry for late reply.&lt;br /&gt;&lt;br /&gt;&lt;/p&gt;
[quote user="Dat Nguyen"]when I debug, I don&amp;#39;t see the sensor parameters (like when I code separately for twi_sensor ).[/quote]
&lt;p&gt;Do you still have this issue?&amp;nbsp; Where do you put the sensor parameters? do you print them or do something else?&amp;nbsp;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: BLE_APP_UART does not work when add twi_sensor</title><link>https://devzone.nordicsemi.com/thread/482342?ContentTypeID=1</link><pubDate>Tue, 07 May 2024 15:02:31 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:b1af3b91-6a29-4af3-bc7c-c1b4db087b29</guid><dc:creator>Dat Nguyen</dc:creator><description>&lt;p&gt;&lt;pre class="ui-code" data-mode="text"&gt;


#include &amp;lt;stdint.h&amp;gt;
#include &amp;lt;string.h&amp;gt;
#include &amp;quot;nordic_common.h&amp;quot;
#include &amp;quot;nrf.h&amp;quot;
#include &amp;quot;ble.h&amp;quot;
#include &amp;quot;ble_hci.h&amp;quot;
#include &amp;quot;ble_advdata.h&amp;quot;
#include &amp;quot;ble_advertising.h&amp;quot;
#include &amp;quot;ble_conn_params.h&amp;quot;
#include &amp;quot;nrf_sdh.h&amp;quot;
#include &amp;quot;nrf_sdh_soc.h&amp;quot;
#include &amp;quot;nrf_sdh_ble.h&amp;quot;
#include &amp;quot;nrf_ble_gatt.h&amp;quot;
#include &amp;quot;nrf_ble_qwr.h&amp;quot;
#include &amp;quot;app_timer.h&amp;quot;
#include &amp;quot;ble_nus.h&amp;quot;
#include &amp;quot;app_uart.h&amp;quot;
#include &amp;quot;app_util_platform.h&amp;quot;
#include &amp;quot;bsp_btn_ble.h&amp;quot;
#include &amp;quot;nrf_pwr_mgmt.h&amp;quot;
#include &amp;quot;cus_service.h&amp;quot;
#include &amp;quot;nrf_drv_twi.h&amp;quot;
#include &amp;quot;app_error.h&amp;quot;
#include &amp;quot;nrf_log.h&amp;quot;
#include &amp;quot;nrf_log_ctrl.h&amp;quot;
#include &amp;quot;nrf_log_default_backends.h&amp;quot;
#include &amp;quot;math.h&amp;quot;

#include &amp;quot;scd4x_i2c.h&amp;quot;
#include &amp;quot;sensirion_common.h&amp;quot;
#include &amp;quot;sensirion_i2c_hal.h&amp;quot;



#if defined (UART_PRESENT)
#include &amp;quot;nrf_uart.h&amp;quot;
#endif
#if defined (UARTE_PRESENT)
#include &amp;quot;nrf_uarte.h&amp;quot;
#endif

#include &amp;quot;nrf_log.h&amp;quot;
#include &amp;quot;nrf_log_ctrl.h&amp;quot;
#include &amp;quot;nrf_log_default_backends.h&amp;quot;

    uint16_t serial_0;
    uint16_t serial_1;
    uint16_t serial_2;
    int16_t error = 0;
    uint16_t co2;
    int32_t temperature;
    int32_t humidity;




#define APP_BLE_CONN_CFG_TAG            1                                           /**&amp;lt; A tag identifying the SoftDevice BLE configuration. */

#define DEVICE_NAME                     &amp;quot;DAT_NGUYEN&amp;quot;                               /**&amp;lt; Name of device. Will be included in the advertising data. */
#define NUS_SERVICE_UUID_TYPE           BLE_UUID_TYPE_VENDOR_BEGIN                  /**&amp;lt; UUID type for the Nordic UART Service (vendor specific). */

#define APP_BLE_OBSERVER_PRIO           3                                           /**&amp;lt; Application&amp;#39;s BLE observer priority. You shouldn&amp;#39;t need to modify this value. */

#define APP_ADV_INTERVAL                64                                          /**&amp;lt; The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */

#define APP_ADV_DURATION                18000                                       /**&amp;lt; The advertising duration (180 seconds) in units of 10 milliseconds. */

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS)             /**&amp;lt; 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)             /**&amp;lt; Maximum acceptable connection interval (75 ms), Connection interval uses 1.25 ms units. */
#define SLAVE_LATENCY                   0                                           /**&amp;lt; Slave latency. */
#define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)             /**&amp;lt; Connection supervisory timeout (4 seconds), Supervision Timeout uses 10 ms units. */
#define FIRST_CONN_PARAMS_UPDATE_DELAY  APP_TIMER_TICKS(5000)                       /**&amp;lt; 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)                      /**&amp;lt; Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT    3                                           /**&amp;lt; Number of attempts before giving up the connection parameter negotiation. */

#define DEAD_BEEF                       0xDEADBEEF                                  /**&amp;lt; Value used as error code on stack dump, can be used to identify stack location on stack unwind. */

#define UART_TX_BUF_SIZE                256                                         /**&amp;lt; UART TX buffer size. */
#define UART_RX_BUF_SIZE                256                                         /**&amp;lt; UART RX buffer size. */


BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT);                                   /**&amp;lt; BLE NUS service instance. */
NRF_BLE_GATT_DEF(m_gatt);                                                           /**&amp;lt; GATT module instance. */
NRF_BLE_QWR_DEF(m_qwr);                                                             /**&amp;lt; Context for the Queued Write module.*/
BLE_ADVERTISING_DEF(m_advertising);                                                 /**&amp;lt; Advertising module instance. */

static uint16_t   m_conn_handle          = BLE_CONN_HANDLE_INVALID;                 /**&amp;lt; Handle of the current connection. */
static uint16_t   m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - 3;            /**&amp;lt; 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[]          =                                          /**&amp;lt; Universally unique service identifier. */
{
    {BLE_UUID_NUS_SERVICE, NUS_SERVICE_UUID_TYPE}
};


/**@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);
}

/**@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(&amp;amp;sec_mode);

    err_code = sd_ble_gap_device_name_set(&amp;amp;sec_mode,
                                          (const uint8_t *) DEVICE_NAME,
                                          strlen(DEVICE_NAME));
    APP_ERROR_CHECK(err_code);

    memset(&amp;amp;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(&amp;amp;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-&amp;gt;type == BLE_NUS_EVT_RX_DATA)
    {
        uint32_t err_code;

        NRF_LOG_DEBUG(&amp;quot;Received data from BLE NUS. Writing data on UART.&amp;quot;);
        NRF_LOG_HEXDUMP_DEBUG(p_evt-&amp;gt;params.rx_data.p_data, p_evt-&amp;gt;params.rx_data.length);

        for (uint32_t i = 0; i &amp;lt; p_evt-&amp;gt;params.rx_data.length; i++)
        {
            do
            {
                err_code = app_uart_put(p_evt-&amp;gt;params.rx_data.p_data[i]);
                if ((err_code != NRF_SUCCESS) &amp;amp;&amp;amp; (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR(&amp;quot;Failed receiving NUS message. Error 0x%x. &amp;quot;, err_code);
                    APP_ERROR_CHECK(err_code);
                }
            } while (err_code == NRF_ERROR_BUSY);
        }
        if (p_evt-&amp;gt;params.rx_data.p_data[p_evt-&amp;gt;params.rx_data.length - 1] == &amp;#39;\r&amp;#39;)
        {
            while (app_uart_put(&amp;#39;\n&amp;#39;) == 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(&amp;amp;m_qwr, &amp;amp;qwr_init);
    APP_ERROR_CHECK(err_code);

    // Initialize NUS.
    memset(&amp;amp;nus_init, 0, sizeof(nus_init));

    nus_init.data_handler = nus_data_handler;

    err_code = ble_nus_init(&amp;amp;m_nus, &amp;amp;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-&amp;gt;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(&amp;amp;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(&amp;amp;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 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-&amp;gt;header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO(&amp;quot;Connected&amp;quot;);
            err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
            APP_ERROR_CHECK(err_code);
            m_conn_handle = p_ble_evt-&amp;gt;evt.gap_evt.conn_handle;
            err_code = nrf_ble_qwr_conn_handle_assign(&amp;amp;m_qwr, m_conn_handle);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO(&amp;quot;Disconnected&amp;quot;);
            // LED indication will be changed when advertising starts.
            m_conn_handle = BLE_CONN_HANDLE_INVALID;
            break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_DEBUG(&amp;quot;PHY update request.&amp;quot;);
            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-&amp;gt;evt.gap_evt.conn_handle, &amp;amp;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-&amp;gt;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-&amp;gt;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, &amp;amp;ram_start);
    APP_ERROR_CHECK(err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&amp;amp;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-&amp;gt;conn_handle) &amp;amp;&amp;amp; (p_evt-&amp;gt;evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED))
    {
        m_ble_nus_max_data_len = p_evt-&amp;gt;params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
        NRF_LOG_INFO(&amp;quot;Data len is set to 0x%X(%d)&amp;quot;, m_ble_nus_max_data_len, m_ble_nus_max_data_len);
    }
    NRF_LOG_DEBUG(&amp;quot;ATT MTU exchange completed. central 0x%x peripheral 0x%x&amp;quot;,
                  p_gatt-&amp;gt;att_mtu_desired_central,
                  p_gatt-&amp;gt;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(&amp;amp;m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_gatt_att_mtu_periph_set(&amp;amp;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(&amp;amp;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
 *          &amp;#39;new line&amp;#39; &amp;#39;\n&amp;#39; (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[BLE_NUS_MAX_DATA_LEN];
    static uint8_t index = 0;
    uint32_t       err_code;

    switch (p_event-&amp;gt;evt_type)
    {
        case APP_UART_DATA_READY:
            UNUSED_VARIABLE(app_uart_get(&amp;amp;data_array[index]));
            index++;

            if ((data_array[index - 1] == &amp;#39;\n&amp;#39;) ||
                (data_array[index - 1] == &amp;#39;\r&amp;#39;) ||
                (index &amp;gt;= m_ble_nus_max_data_len))
            {
                if (index &amp;gt; 1)
                {
                    NRF_LOG_DEBUG(&amp;quot;Ready to send data over BLE NUS&amp;quot;);
                    NRF_LOG_HEXDUMP_DEBUG(data_array, index);

                    do
                    {
                        uint16_t length = (uint16_t)index;
                        err_code = ble_nus_data_send(&amp;amp;m_nus, data_array, &amp;amp;length, m_conn_handle);
                        if ((err_code != NRF_ERROR_INVALID_STATE) &amp;amp;&amp;amp;
                            (err_code != NRF_ERROR_RESOURCES) &amp;amp;&amp;amp;
                            (err_code != NRF_ERROR_NOT_FOUND))
                        {
                            APP_ERROR_CHECK(err_code);
                        }
                    } while (err_code == NRF_ERROR_RESOURCES);
                }

                index = 0;
            }
            break;

        case APP_UART_COMMUNICATION_ERROR:
            APP_ERROR_HANDLER(p_event-&amp;gt;data.error_communication);
            break;

        case APP_UART_FIFO_ERROR:
            APP_ERROR_HANDLER(p_event-&amp;gt;data.error_code);
            break;

        default:
            break;
    }
}
/**@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(&amp;amp;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)
{
    uint32_t               err_code;
    ble_advertising_init_t init;

    memset(&amp;amp;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(&amp;amp;m_advertising, &amp;amp;init);
    APP_ERROR_CHECK(err_code);

    ble_advertising_conn_cfg_tag_set(&amp;amp;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, &amp;amp;startup_event);
    APP_ERROR_CHECK(err_code);

    *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}


/**@brief Function for initializing the nrf log module.
 */
static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


/**@brief Function for initializing power management.
 */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop).
 *
 * @details If there is no pending log operation, then sleep until next the next event occurs.
 */
static void idle_state_handle(void)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}


/**@brief Function for starting advertising.
 */
static void advertising_start(void)
{
    uint32_t err_code = ble_advertising_start(&amp;amp;m_advertising, BLE_ADV_MODE_FAST);
    APP_ERROR_CHECK(err_code);
}


/**@brief Application main function.
 */
int main(void)
{

    bool erase_bonds;
    // Initialize.
    uart_init();
    log_init();
    timers_init();
    buttons_leds_init(&amp;amp;erase_bonds);
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();

// Sensor SCD41
    printf(&amp;quot;Hello\n&amp;quot;);
    sensirion_i2c_hal_init();
    // Clean up potential SCD40 states
    ret_code_t err_code;
    int16_t error = 0;
    scd4x_wake_up();
    scd4x_stop_periodic_measurement();
    scd4x_reinit();
       error = scd4x_get_serial_number(&amp;amp;serial_0, &amp;amp;serial_1, &amp;amp;serial_2);
    if (error) {
        printf(&amp;quot;Error executing scd4x_get_serial_number(): %i\n&amp;quot;, error);
    } else {
        printf(&amp;quot;serial: 0x%04x%04x%04x\n&amp;quot;, serial_0, serial_1, serial_2);
    }

    // Start Measurement

    error = scd4x_start_low_power_periodic_measurement(); // Do theo chu ki 30s, sau khi do roi vao trang thai idle(sleep) ti?t ki?m nang lu?ng 
    if (error) {
        printf(&amp;quot;Error executing scd4x_start_periodic_measurement(): %i\n&amp;quot;,
               error);
    }

    printf(&amp;quot;Waiting for first measurement... (5 sec)\n&amp;quot;);
 
 
    // Start execution.
    printf(&amp;quot;\r\nUART started.\r\n&amp;quot;);
    NRF_LOG_INFO(&amp;quot;Debug logging for UART over RTT started.&amp;quot;);
    advertising_start();
  

      for (;;) {
        // Read Measurement
        sensirion_i2c_hal_sleep_usec(100000);
        bool data_ready_flag = false;
        error = scd4x_get_data_ready_flag(&amp;amp;data_ready_flag);
        if (error) {
            printf(&amp;quot;Error executing scd4x_get_data_ready_flag(): %i\n&amp;quot;, error);
            continue;
        }
        if (!data_ready_flag) {
            continue;
        }

        error = scd4x_read_measurement(&amp;amp;co2, &amp;amp;temperature, &amp;amp;humidity);
        if (error) {

        } else if (co2 == 0) {

        } else {
            printf(&amp;quot;CO2: %u ppm\n&amp;quot;, co2);

        }
    }


    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
    }
}


/**
 * @}
 */
&lt;/pre&gt;&lt;/p&gt;
&lt;p&gt;Hi JONATHAN, this is my main.c.&amp;nbsp;I have fixed the communication error (when using nrf connect I can connect), but there is one problem: when I debug, I don&amp;#39;t see the sensor parameters (like when I code separately for twi_sensor ).&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: BLE_APP_UART does not work when add twi_sensor</title><link>https://devzone.nordicsemi.com/thread/482311?ContentTypeID=1</link><pubDate>Tue, 07 May 2024 13:56:22 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:122d2630-4d21-4ef4-9f84-214160bbde01</guid><dc:creator>JONATHAN LL</dc:creator><description>&lt;p&gt;Hi,&lt;br /&gt;&lt;br /&gt;Do you also flash and program the MCU ?&amp;nbsp;&lt;br /&gt;&lt;br /&gt;Do you have some log output that you can share ?&lt;br /&gt;&lt;br /&gt;Did you erase the MCU before programming it again ?&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>