BLE data rate

how to change the BLE data transmission rate in nrf52840 sdk s140?

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  • 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);
    
        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);
    }

    in this code where actually data rate was initialised i am reffering the ble uart example

Children
  • Line 16-19 of the code snippet is where the connection parameter preferences of the peripheral device is set. However, please note that the peripheral may only make requests to use its preferred parameters, while the central is the one that actually decides which parameters will be used. The central may reject the peripheral's request, if it prefers other parameters itself. This is not a problem if you control both sides of the link, but in the case of a phone or similar it is worth noting.

    Are you familiar with the nRF Sniffer tool? It is a powerful tool to wield when developing with BLE since it lets you see the on-air exchanges between your devices. In this case, a sniffer trace would immediately let you see which connection parameters is being used for the connection.

    Best regards,
    Karl

  • line 16 and 19 represent the max_connection interval and connection time out but i am asking about data rate either 1mbps/2mbps where actually that is set?

  • "but i am asking about data rate either 1mbps/2mbps where actually that is set?"

    The default bitrate is 1mbps. This is established through the advertisement preceding the connection.

    During the connection you can update the PHY on one side of the connection. If the other side of the connection gets the update event and accepts the PHY update, the new PHY will be used.

    Have a look at :github.com/.../main.c

  • Hi karl i have set the connection interval between 20ms to 70ms ,and data length 20bytes and i have set the txphy and rxphy to coded phy  and tx power to 8dbm in advertisement initialisation as well as when device connected but there is not improvement in range i dont know what might be the issue can u help me?

  • /**
     * Copyright (c) 2014 - 2021, Nordic Semiconductor ASA
     *
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     *
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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 <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_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"
    
    #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_spi.h"
    #include "nrf_gpio.h"
    #include "nrf_delay.h"
    #include "boards.h"
    #include "EPD_1in54_V2.h"
    #include "EPD_Test.h"
    #include "nrf_drv_gpiote.h"
    #include "GUI_Paint.h"
    
    #define SPI_SS_PIN          31
    #define SPI_MISO_PIN        30
    #define SPI_MOSI_PIN        29
    #define SPI_SCK_PIN         26
    #define LED_Pin              5 
    
    #define SPI_INSTANCE  0 /**< SPI instance index. */
     nrf_drv_spi_t spi = NRF_DRV_SPI_INSTANCE(SPI_INSTANCE);  /**< SPI instance. */
     bool spi_xfer_done;  /**< Flag used to indicate that SPI instance completed the transfer. */
    
    
    #define APP_BLE_CONN_CFG_TAG            1                                           /**< A tag identifying the SoftDevice BLE configuration. */
    
    #define DEVICE_NAME                     "Nordic_UART"                               /**< 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                1600                                          /**< 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. */
    
    
    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. */
    
    static uint8_t m_adv_handle = BLE_GAP_ADV_SET_HANDLE_NOT_SET;                       //Advertising handle to set the phy rate
    static uint8_t m_enc_advdata[BLE_GAP_ADV_SET_DATA_SIZE_MAX];            /**< Buffer for storing an encoded advertising set. */
    static uint8_t m_enc_scan_response_data[BLE_GAP_ADV_SET_DATA_SIZE_MAX]; /**< Buffer for storing an encoded scan data. */
    
    APP_TIMER_DEF(my_timer_id);                                                         //added by me
    
    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}
    };
    
    uint8_t flag = 0;
    uint8_t count = 48;
    int8_t rssi; 
    
     void in_pin_handle(nrf_drv_gpiote_pin_t pin,nrf_gpiote_polarity_t action)
     {
        if(pin == BUTTON_1)
        {
           nrf_gpio_pin_toggle(LED_2);
          count = 0;
          flag = 1;
         // Set_Count(count);
        }
        if(pin == BUTTON_2)
        {
          // nrf_gpio_pin_toggle(LED_2);
          count = 1;
          flag = 2;
          //Set_Count(count);
        }
     }
     void gpio_init(void)
     {
       
       ret_code_t error_code;
       error_code = nrf_drv_gpiote_init();
       APP_ERROR_CHECK( error_code);
    
       nrf_gpio_cfg_output(EPD_CS_PIN);
       nrf_gpio_cfg_output( EPD_DC_PIN);
       nrf_gpio_cfg_output( EPD_RST_PIN);
       nrf_gpio_cfg_input(EPD_BUSY_PIN,NRF_GPIO_PIN_NOPULL);
    
       nrf_drv_gpiote_in_config_t in_config = GPIOTE_CONFIG_IN_SENSE_LOTOHI(true);
       in_config.pull = NRF_GPIO_PIN_PULLUP;
    
       error_code = nrf_drv_gpiote_in_init(BUTTON_1,&in_config,in_pin_handle);
       error_code = nrf_drv_gpiote_in_init(BUTTON_2,&in_config,in_pin_handle);
    
       APP_ERROR_CHECK(error_code);
    
       nrf_drv_gpiote_in_event_enable(BUTTON_1,true);
       nrf_drv_gpiote_in_event_enable(BUTTON_2,true);
     }
    
     void spi_event_handler(nrf_drv_spi_evt_t const * p_event, void *p_context)
    {
        spi_xfer_done = true;
      //  NRF_LOG_INFO("Transfer completed.");
        /*
        if (m_rx_buf[0] != 0)
        {
            NRF_LOG_INFO(" Received:");
            NRF_LOG_HEXDUMP_INFO(m_rx_buf, strlen((const char *)m_rx_buf));
        }*/
    }
    
     void Spi0_init(void)
    {
        nrf_drv_spi_config_t spi_config ;
        spi_config.ss_pin   = SPI_SS_PIN;
        spi_config.miso_pin = SPI_MISO_PIN;
        spi_config.mosi_pin = SPI_MOSI_PIN;
        spi_config.sck_pin  = SPI_SCK_PIN;
        spi_config.frequency = NRF_SPI_FREQ_8M;
        spi_config.mode = NRF_SPI_MODE_0;
        spi_config.bit_order = NRF_SPI_BIT_ORDER_MSB_FIRST;
        APP_ERROR_CHECK(nrf_drv_spi_init(&spi, &spi_config, spi_event_handler, NULL));
    }
    
    /**@brief Struct that contains pointers to the encoded advertising data. */
    static ble_gap_adv_data_t m_adv_data =
    {
            .adv_data =
            {
                    .p_data = m_enc_advdata,
                    .len = BLE_GAP_ADV_SET_DATA_SIZE_MAX
            },
            .scan_rsp_data =
            {
                    .p_data = m_enc_scan_response_data,
                    .len = BLE_GAP_ADV_SET_DATA_SIZE_MAX
    
            }
    };
    /**@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(&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 void nus_data_handler(ble_nus_evt_t * p_evt)
    {
       char Rx_buffer[p_evt->params.rx_data.length];
    
        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++)
            {
                  //Paint_DrawNum(105, 20, p_evt->params.rx_data.p_data[i], &Font24,BLACK,WHITE);
                 // Paint_DrawString_EN(105, 20, p_evt->params.rx_data.p_data[i], &Font24,BLACK,WHITE);
                 /*  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);
                    }*/
                
                //Set_Count(p_evt->params.rx_data.p_data[i]);
               // Paint_DrawNum(105, 20, p_evt->params.rx_data.p_data[i], &Font24,BLACK,WHITE);
                 Rx_buffer[i] = p_evt->params.rx_data.p_data[i];
               // Display_string(p_evt->params.rx_data.p_data[i]);
              // Led_State(p_evt->params.rx_data.p_data[i]-48);
              
            }
    
             Display_string(Rx_buffer);
           /* 
            if (p_evt->params.rx_data.p_data[p_evt->params.rx_data.length - 1] == '\r')
            {
                while (app_uart_put('\n') == NRF_ERROR_BUSY);
               //while (Paint_DrawChar(105,20,'\n',BLACK,WHITE) == 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 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;
        ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt; // ADDED BY ME
         uint8_t channel;
    
        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 = sd_ble_gap_rssi_start(p_ble_evt->evt.gap_evt.conn_handle,BLE_GAP_RSSI_THRESHOLD_INVALID,0); //ADDED BY ME
                APP_ERROR_CHECK(err_code); //ADDED BY ME
    
                err_code = app_timer_start(my_timer_id,APP_TIMER_TICKS(5000),0); //ADDED BY ME
                APP_ERROR_CHECK(err_code); //ADDED BY ME
                err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
                APP_ERROR_CHECK(err_code);
                err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_CONN,  m_conn_handle, 8);
                APP_ERROR_CHECK(err_code);
             //update the phy rate to 2mbps
                 NRF_LOG_INFO("PHY update requested.");
                ble_gap_phys_t const phys =
                {
                    .rx_phys = BLE_GAP_PHY_CODED,
                    .tx_phys = BLE_GAP_PHY_CODED,
                };
                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_DISCONNECTED:
                NRF_LOG_INFO("Disconnected");
                // 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("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;
    
        /*   case  BLE_GAP_EVT_SCAN_REQ_REPORT:
                 err_code = sd_ble_gap_rssi_get(m_conn_handle,&rssi,&channel);
                APP_ERROR_CHECK(err_code);
                NRF_LOG_INFO("RSSI: %d", rssi);
            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;
        //uint8_t data_array1 = count;
       // uint8_t len = sizeof(count);
       uint8_t str[BLE_NUS_MAX_DATA_LEN] = "123456789";
       uint16_t len = strlen(str);
        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;
             case BSP_EVENT_KEY_2:
                // Set_Count(count-48);
                 for(uint32_t i = 0; i < 200000; i++)
                 {
                    err_code = ble_nus_data_send(&m_nus, str, &len, m_conn_handle);
                 }
                // err_code = ble_nus_data_send(&m_nus, &data_array1, &len, m_conn_handle);
                bsp_board_led_invert(BSP_BOARD_LED_3);
            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[BLE_NUS_MAX_DATA_LEN];
        static uint8_t index = 0;
        uint32_t       err_code;
    
        switch (p_event->evt_type)
        {
            case APP_UART_DATA_READY:
                UNUSED_VARIABLE(app_uart_get(&data_array[index]));
                index++;
    
                if ((data_array[index - 1] == '\n') ||
                    (data_array[index - 1] == '\r') ||
                    (index >= m_ble_nus_max_data_len))
                {
                    if (index > 1)
                    {
                        NRF_LOG_DEBUG("Ready to send data over BLE NUS");
                        NRF_LOG_HEXDUMP_DEBUG(data_array, index);
    
                        do
                        {
                            uint16_t length = (uint16_t)index;
                            err_code = ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
                            if ((err_code != NRF_ERROR_INVALID_STATE) &&
                                (err_code != NRF_ERROR_RESOURCES) &&
                                (err_code != NRF_ERROR_NOT_FOUND))
                            {
                                APP_ERROR_CHECK(err_code);
                            }
                        } while (err_code == NRF_ERROR_RESOURCES);
                    }
    
                    index = 0;
                }
                break;
    
            case APP_UART_COMMUNICATION_ERROR:
                APP_ERROR_HANDLER(p_event->data.error_communication);
                break;
    
            case APP_UART_FIFO_ERROR:
                APP_ERROR_HANDLER(p_event->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(&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)
    {
         int8_t tx_power_level = 8;
        uint32_t               err_code;
        ble_advertising_init_t init;
        ble_gap_adv_params_t adv_params;
    
        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.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;
    
        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.config.ble_adv_fast_timeout  = 0;
        init.evt_handler = on_adv_evt;
    
      /*  err_code = ble_advdata_encode(&init.advdata, m_adv_data.adv_data.p_data, &m_adv_data.adv_data.len);
        APP_ERROR_CHECK(err_code);
        err_code = ble_advdata_encode(&init.srdata, m_adv_data.scan_rsp_data.p_data, &m_adv_data.scan_rsp_data.len);
        APP_ERROR_CHECK(err_code);*/
    
        adv_params.primary_phy = BLE_GAP_PHY_CODED;
        adv_params.secondary_phy = BLE_GAP_PHY_CODED;
        adv_params.duration = APP_ADV_DURATION;
        adv_params.p_peer_addr = NULL;
        adv_params.filter_policy = BLE_GAP_ADV_FP_ANY;
        adv_params.interval = APP_ADV_INTERVAL;
    
       // err_code = sd_ble_gap_adv_set_configure(&m_adv_handle, &m_adv_data, &adv_params);
      //  APP_ERROR_CHECK(err_code);
    
         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);
    
         err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, m_advertising.adv_handle, tx_power_level);
         APP_ERROR_CHECK(err_code);
    }
    
    
    /**@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 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(&m_advertising, BLE_ADV_MODE_FAST);
        APP_ERROR_CHECK(err_code);
    }
    
    
    static void timeout_handler(void *timeoutpointer)
    {
                int8_t rssi;
                uint8_t channel;
    
                uint32_t err_code = sd_ble_gap_rssi_get(m_conn_handle,&rssi,&channel);
                APP_ERROR_CHECK(err_code);
                NRF_LOG_INFO("RSSI: %d", rssi);
    }
    /**@brief Application main function.
     */
    int main(void)
    {
       int8_t tx_power_level = 0;
       uint32_t               err_code;
       nrf_gpio_cfg_output(EPD_CS_PIN);
       nrf_gpio_cfg_output( EPD_DC_PIN);
       nrf_gpio_cfg_output( EPD_RST_PIN);
       nrf_gpio_cfg_input(EPD_BUSY_PIN,NRF_GPIO_PIN_NOPULL);
        bool erase_bonds;
    
       // gpio_init();
        Spi0_init();
        // Initialize.
        uart_init();
        log_init();
        timers_init();
        buttons_leds_init(&erase_bonds);
        power_management_init();
        ble_stack_init();
        gap_params_init();
        gatt_init();
        services_init();
        advertising_init();
        conn_params_init();
    
        // Start execution.
       // printf("\r\nUART started.\r\n");
       // NRF_LOG_INFO("Debug logging for UART over RTT started.");
        err_code = app_timer_create(&my_timer_id, APP_TIMER_MODE_REPEATED , timeout_handler); //ADDED BY ME
        APP_ERROR_CHECK(err_code);// ADDED BY ME
        advertising_start();
       // nrf_delay_ms(100); 
      //  err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, m_advertising.adv_handle, tx_power_level);
      //  APP_ERROR_CHECK(err_code);
      
    
         Display_Init();
        // Draw_Image();
       //  Day_Fill(tuesday);
       //  Time_Fill(evening);
    
        // Enter main loop.
        for (;;)
        {
            idle_state_handle();
        }
    }
    
    
    /**
     * @}
     */
    

    this is the code

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