BMI160 + NRF52832 + I2C

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Mon, 01 Feb 2021 07:15:48 GMT

assign it as

char str[80;
uint16_t length1;

and check it and also check for update in nrfconnect app

when ever you try to send the data in nrf connect it will show the receiving hex , and it was missing here

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Fri, 22 Jan 2021 08:53:23 GMT

[quote user="Parker Bondi"]It seems to me that either I'm not getting data from the accelerometer or I'm not converting it to a string correctly.[/quote]

That should be easy to check. Just run the debugger and check if the values in the 'accel' struct is what you expect or not.

RE: BMI160 + NRF52832 + I2C

Parker Bondi — Fri, 22 Jan 2021 00:38:15 GMT

Hey Nordic,

I'm trying to follow along this thread to create a bluetooth accelerometer project and I just can't seem to get it to work.

I have tried to follow the instructions as closely as possible.

#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_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_drv_twi.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 "bmi160.h"

/* TWI instance ID. */
#define TWI_INSTANCE_ID     0

#define G_TO_LSB (16384.0f)

#define DPS_TO_LSB (131.072f)

#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                64                                          /**< 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. */

/* Indicates if operation on TWI has ended. */
static volatile bool m_xfer_done = false;

/* TWI instance. */
static const nrf_drv_twi_t m_twi = NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID);

struct bmi160_dev sensor;
struct bmi160_sensor_data accel;
struct bmi160_sensor_data gyro;


int8_t rslt = BMI160_OK;


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 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}
};






/**@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)
{

    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 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");
            // 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;

        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[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)
{
    uint32_t               err_code;
    ble_advertising_init_t init;

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

    init.advdata.name_type          = BLE_ADVDATA_FULL_NAME;
    init.advdata.include_appearance = false;
    init.advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;

    init.srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.srdata.uuids_complete.p_uuids  = m_adv_uuids;

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

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

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}


/**@brief Function for initializing 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)
{
    UNUSED_RETURN_VALUE(NRF_LOG_PROCESS());
    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);
}



/*TWI initialization*/

void twi_init (void)
{
    ret_code_t err_code;

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

    err_code = nrf_drv_twi_init(&m_twi, &twi_config, NULL, NULL);
    
    APP_ERROR_CHECK(err_code);
    if (NRF_SUCCESS == err_code)
	{
		nrf_drv_twi_enable(&m_twi);
		NRF_LOG_INFO("TWI init success...");	
	}
}

int8_t Acc_i2c_Write(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
{

    //  NRF_LOG_INFO("WRITE: dev_id: %x reg_addr: %x reg_data: %x len: %i\n", dev_id, reg_addr, *reg_data, len);
	int8_t rslt = 0;
	uint8_t data[len + 1];
	data[0] = reg_addr;
	for (uint16_t i = 0; i < len; i++) {
		data[i + 1] = reg_data[i];
	}
	
	rslt = nrf_drv_twi_tx(&m_twi, dev_id, data, len + 1, false);
	APP_ERROR_CHECK(rslt);
        return rslt;
  
}


int8_t Acc_i2c_Read(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
{
	int8_t rslt = 0;
   //     NRF_LOG_INFO("READ: dev_id: %x reg_addr: %x len: %i\n", dev_id, reg_addr, len);
	rslt = nrf_drv_twi_tx(&m_twi, dev_id, &reg_addr, 1, true);
        APP_ERROR_CHECK(rslt);

	if (rslt == 0)
	{
		rslt = nrf_drv_twi_rx(&m_twi, dev_id, reg_data, len);
	}
    //    NRF_LOG_INFO("READ: %x",*reg_data);
	return rslt;
}

void Acc_delay_ms(uint32_t period)
{ 
	
/*if (period==NULL){
period = 1;
}// delay time*/
	
  nrf_delay_ms( period ) ;
}


void BMI160_init (void)
{
    sensor.id = BMI160_I2C_ADDR;         //0x69
    sensor.interface = BMI160_I2C_INTF;  //0x00
    sensor.read = &Acc_i2c_Read;
    sensor.write = &Acc_i2c_Write;
    sensor.delay_ms = &Acc_delay_ms;

    rslt = bmi160_init(&sensor);
    APP_ERROR_CHECK(rslt);

    if(rslt == BMI160_OK){
    NRF_LOG_INFO("BMI160 Initialized...");
    } else {
    NRF_LOG_INFO("BMI160 not Initialized...");
    }//NRF_LOG_FLUSH();

    sensor.accel_cfg.odr = BMI160_ACCEL_ODR_1600HZ;
    sensor.accel_cfg.range = BMI160_ACCEL_RANGE_2G;
    sensor.accel_cfg.bw = BMI160_ACCEL_BW_NORMAL_AVG4;
    sensor.accel_cfg.power = BMI160_ACCEL_NORMAL_MODE;

    sensor.gyro_cfg.odr = BMI160_GYRO_ODR_3200HZ;
    sensor.gyro_cfg.range = BMI160_GYRO_RANGE_2000_DPS;
    sensor.gyro_cfg.bw = BMI160_GYRO_BW_NORMAL_MODE;
    sensor.gyro_cfg.power = BMI160_GYRO_NORMAL_MODE;

    rslt = bmi160_set_sens_conf(&sensor);
    APP_ERROR_CHECK(rslt);

     if(rslt == BMI160_OK){
    NRF_LOG_INFO("sensor Configured...");
    } else {
    NRF_LOG_INFO("sensor not Configured...");
    }//NRF_LOG_FLUSH();
}



static void read_sensor_data()
{
      m_xfer_done = false;
      uint16_t data_array1;
      static uint8_t index = 11;
      int length1 = 2;
      char* str;

       //err_code = ble_mpu_update(&m_mpu, &accel_values);
      //              APP_ERROR_CHECK(err_code);
      
      bmi160_get_sensor_data(BMI160_ACCEL_SEL, &accel, NULL, &sensor);
      data_array1 = accel.x;
      length1 = sprintf(str, "ACCX: %5d", data_array1);
      rslt = ble_nus_data_send(&m_nus, &str, &length1, m_conn_handle);
      //APP_ERROR_CHECK(rslt);
      //NRF_LOG_HEXDUMP_DEBUG(str,  index);
      //rslt = ble_nus_data_send(&m_nus, str, &length1, m_conn_handle);
      
      //NRF_LOG_INFO("DataX:%d", accel.x);
      //length1 = sprintf(str, "Value of AccX: %5d", data_array1);
      //length2 = sprintf(str, "Value of AccX = %5d", accel.x);
      //NRF_LOG_INFO("DataY:%d", accel.y);
      //NRF_LOG_INFO("DataZ:%d", accel.z);
      //NRF_LOG_INFO("GyroX:%d", gyro.x);
      //NRF_LOG_INFO("GyroY:%d", gyro.y);
      //NRF_LOG_INFO("GyroZ:%d", gyro.z);
      Acc_delay_ms(100);
      NRF_LOG_FLUSH();
}

/**@brief Application main function.
 */
int main(void)
{
    bool erase_bonds;
    uint8_t sample_data[10];

    // 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("BMI160 get started...");
    printf("\r\BMI160 started.\r\n");
    Acc_delay_ms(100);
    advertising_start();
    printf("\r\advertising started.\r\n");

    Acc_delay_ms(100);

    twi_init();
    printf("\r\twi_init.\r\n");

    Acc_delay_ms(50);

    BMI160_init();
    printf("\r\BMI160_init.\r\n");
    Acc_delay_ms(100);

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

    //for (;;)
    //{
    //    idle_state_handle();
    //    nrf_delay_ms( 1000 ) ;
    //    read_sensor_data();
    //    NRF_LOG_FLUSH();
    //    nrf_delay_ms( 100 ) ;
   //     sample_data[0] = 0x20;
   //     sample_data[1] = 0x21;
   //     nrf_drv_twi_tx(&m_twi, 0x69, sample_data, 2, false);
   //     nrf_drv_twi_rx(&m_twi, 0x69, sample_data, 2);
      //  NRF_LOG_INFO("Temperature:" NRF_LOG_FLOAT_MARKER, 
      //  NRF_LOG_FLOAT((((sample_data[1]<<8|sample_data[0])*0.001953125)+23.0)));
      //  NRF_LOG_FLUSH();
     //   nrf_delay_ms( 300 ) ;
    //    float accelX = ((((float)accel.x) / G_TO_LSB) * 9.80655); // in m/s^2
    //    float gyrX = ((((float)gyro.x) / DPS_TO_LSB) * 0.0174532925); // in rad/sec
    //    NRF_LOG_INFO("DataX in m/s^2   : " NRF_LOG_FLOAT_MARKER, 
   //     NRF_LOG_FLOAT( accelX));
   //     NRF_LOG_INFO("DataY in rad/sec : " NRF_LOG_FLOAT_MARKER, 
   //     NRF_LOG_FLOAT(gyrX));
       // NRF_LOG_FLUSH();

    //}
}

It seems to me that either I'm not getting data from the accelerometer or I'm not converting it to a string correctly.

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Wed, 21 Aug 2019 06:53:11 GMT

can you explain it deep.

where did you got the breakpoints

double click here it will show the error occur on which line

RE: BMI160 + NRF52832 + I2C

klcheung — Mon, 19 Aug 2019 08:04:16 GMT

I am doing a similar project, hoping to use 52840 to communicate with the BMI160. I re-configured the pin assignments and tried to programme it. I used same code. Can you offer me some help?

#include <stdio.h>
#include "boards.h"
#include "app_util_platform.h"
#include "app_error.h"
#include "nrf_drv_twi.h"
#include "nrf_delay.h"


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

#include "bmi160.h"

/* TWI instance ID. */
#define TWI_INSTANCE_ID     0


/* Indicates if operation on TWI has ended. */
static volatile bool m_xfer_done = false;

/* TWI instance. */
static const nrf_drv_twi_t m_twi = NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID);

struct bmi160_dev sensor;
struct bmi160_sensor_data accel;
struct bmi160_sensor_data gyro;


int8_t rslt = BMI160_OK;


/*TWI initialization*/

void twi_init (void)
{
    ret_code_t err_code;

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

    err_code = nrf_drv_twi_init(&m_twi, &twi_config, NULL, NULL);
    
    APP_ERROR_CHECK(err_code);
    if (NRF_SUCCESS == err_code)
	{
		nrf_drv_twi_enable(&m_twi);
		NRF_LOG_INFO("TWI init success...");	
	}
}

int8_t Acc_i2c_Write(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
{

    //  NRF_LOG_INFO("WRITE: dev_id: %x reg_addr: %x reg_data: %x len: %i\n", dev_id, reg_addr, *reg_data, len);
	int8_t rslt = 0;
	uint8_t data[len + 1];
	data[0] = reg_addr;
	for (uint16_t i = 0; i < len; i++) {
		data[i + 1] = reg_data[i];
	}
	
	rslt = nrf_drv_twi_tx(&m_twi, dev_id, reg_data, len + 1, false);
	APP_ERROR_CHECK(rslt);
        return rslt;
  
}


int8_t Acc_i2c_Read(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
{
	int8_t rslt = 0;
   //     NRF_LOG_INFO("READ: dev_id: %x reg_addr: %x len: %i\n", dev_id, reg_addr, len);
	rslt = nrf_drv_twi_tx(&m_twi, dev_id, &reg_addr, 1, false);
        APP_ERROR_CHECK(rslt);

	if (rslt == 0)
	{
		rslt = nrf_drv_twi_rx(&m_twi, dev_id, reg_data, len);
	}
    //    NRF_LOG_INFO("READ: %x",*reg_data);
	return rslt;
}

void Acc_delay_ms(uint32_t period)
{ 
	
/*if (period==NULL){
period = 1;
}// delay time*/
	
  nrf_delay_ms( period ) ;
}


void BMI160_init (void)
{
    sensor.id = BMI160_I2C_ADDR;         //0x69
    sensor.interface = BMI160_I2C_INTF;  //0x00
    sensor.read = &Acc_i2c_Read;
    sensor.write = &Acc_i2c_Write;
    sensor.delay_ms = &Acc_delay_ms;

    rslt = bmi160_init(&sensor);
    APP_ERROR_CHECK(rslt);

    if(rslt == BMI160_OK){
    NRF_LOG_INFO("BMI160 Initialized...");
    } else {
    NRF_LOG_INFO("BMI160 not Initialized...");
    }NRF_LOG_FLUSH();

    sensor.accel_cfg.odr = BMI160_ACCEL_ODR_1600HZ;
    sensor.accel_cfg.range = BMI160_ACCEL_RANGE_2G;
    sensor.accel_cfg.bw = BMI160_ACCEL_BW_NORMAL_AVG4;
    sensor.accel_cfg.power = BMI160_ACCEL_NORMAL_MODE;

    sensor.gyro_cfg.odr = BMI160_GYRO_ODR_100HZ;
    sensor.gyro_cfg.range = BMI160_GYRO_RANGE_2000_DPS;
    sensor.gyro_cfg.bw = BMI160_GYRO_BW_NORMAL_MODE;
    sensor.gyro_cfg.power = BMI160_GYRO_NORMAL_MODE;

    rslt = bmi160_set_sens_conf(&sensor);
    APP_ERROR_CHECK(rslt);

     if(rslt == BMI160_OK){
    NRF_LOG_INFO("sensor Configured...");
    } else {
    NRF_LOG_INFO("sensor not Configured...");
    }NRF_LOG_FLUSH();
}

static void read_sensor_data()
{
      m_xfer_done = false;
      bmi160_get_sensor_data(BMI160_ACCEL_SEL, &accel, NULL, &sensor);
      NRF_LOG_INFO("DataX:%d", accel.x);
      NRF_LOG_INFO("DataY:%d", accel.y);
      NRF_LOG_INFO("DataZ:%d", accel.z);
}


int main(void)
{
    bsp_board_init(BSP_INIT_LEDS);
    APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
    NRF_LOG_DEFAULT_BACKENDS_INIT();

    NRF_LOG_INFO("BMI160 get started.\n");
    NRF_LOG_FLUSH();
    Acc_delay_ms(100);

    twi_init();
    Acc_delay_ms(50);

    BMI160_init();
    Acc_delay_ms(100);

    while(true)
    {
      nrf_delay_ms( 1000 ) ;
      /* do
        {
            __WFE();
        }while (m_xfer_done == false);*/
        read_sensor_data();
        NRF_LOG_FLUSH();
    }
}

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Mon, 26 Nov 2018 13:20:06 GMT

Yes, all GPIOs can be used for interrupts. There is a Pin Change Interrupt Example in the SDK. You need to configure interrupts in the BMI160 as described in the datasheet, I do not know if this is supported on that device. There is a TWI + Interrupt examples available in this repository.

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Fri, 23 Nov 2018 14:21:46 GMT

1. How to use INT 1 and INT 2 of BMI160 to NRF52832. any gpio can be used for this interrupt.

2. from BMI160 is it possible to give interrupt to wake up the controller (i.e : while TILT detection it will wake up the controller to do the calculation.

3. is there any interrupt code example for the I2C

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Thu, 22 Nov 2018 14:49:35 GMT

This is not at all related to the topic of this post. Please post your questions in a new thread.

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Thu, 22 Nov 2018 14:39:16 GMT

Hi Jorgen,

I diidn't understand this function in BLE_UART

is there any tutorial or can you explain

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);
}

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Thu, 22 Nov 2018 14:33:22 GMT

Yes, this is correct if you have setup the SAADC to sample analog input AIN0, however it is not necessary to physically connect the VDD to this pin. You can also set the SAADC input to NRF_SAADC_INPUT_VDD (passed as parameter to NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE).

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Thu, 22 Nov 2018 10:01:09 GMT

Hi jorgen,

i got the SAADC values by connecting the P0.02 pin to VDD. if the voltage drop occur this adc value becomes drop. is this correct one or any thing to be change.

if the method that i done is correct. for hardware protection we need add any resistance or any internal protection circuit is there for the pin.?

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Mon, 19 Nov 2018 12:42:00 GMT

You cannot read the voltage using internal registers, you need to use the SAADC. There is an SAADC input for VDD, you do not need to connect anything physical.

The necessary code to do this is shown in the proximity example (as you know). You need to include all the code related to SAADC and the timers that is triggering the sampling. You also need to add the required drivers/libraries to the project.

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Mon, 19 Nov 2018 12:15:49 GMT

Hi Jorgen,

I need to read the battery value. but with out adc is it possible to read the battery level with internal registers. ?

If adc is used means can you give any schematic related to ADC connection. It will be helpful for my project.

How to add the proximity into my device. that i need to know how much distance between the device and mobile phone and the device is in out of range or in the specified range. the LED in the device should blink and mobile phone receive alert notification.

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Sat, 10 Nov 2018 05:26:15 GMT

Hi jorgen,

[quote userid="14926" url="~/f/nordic-q-a/39742/bmi160-nrf52832-i2c/156487"]ble_app_uart_c: ble_nus_c_tx_notif_enable()[/quote]

In the above function for central . the device will act as central and mobile phone is act as Peer.

so that when I'm connect to the device that time i need to enable the notification and it will send the data to mobile phone. otherwise its in disable condition.

Is it right?

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Thu, 08 Nov 2018 12:24:54 GMT

Yes, most BLE central examples have this:

ble_app_blinky_c: ble_lbs_c_button_notif_enable()
ble_app_uart_c: ble_nus_c_tx_notif_enable()
ble_app_hrs_c: ble_hrs_c_hrm_notif_enable()
And so on..

In nRF Connect mobile app you can enable notifications by opening the service to show characteristics and clicking the three arrows next to the characteristics that support notifications.

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Thu, 08 Nov 2018 04:41:29 GMT

HI,

I am not able to understand this

[quote userid="14926" url="~/f/nordic-q-a/39742/bmi160-nrf52832-i2c/155992"]ou should only call ble_nus_data_send when you are in a connection and notifications have been enabled by the central.[/quote]

How to enable or disable the notifications by using central

Is there any example?

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Mon, 05 Nov 2018 14:37:38 GMT

You should only call ble_nus_data_send when you are in a connection and notifications have been enabled by the central.

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Thu, 01 Nov 2018 04:30:48 GMT

this error happen when i move the sensor fast.

in the above image

rslt is the return err_ode from BMI init();

rsltr is the return err_code from Acc_i2c_Read();

rsltw from Acc_i2c_Write();

rsltb from ble_nus_data_send();

    rslt = bmi160_init(&sensor);
    APP_ERROR_CHECK(rslt);


  rslt = bmi160_set_sens_conf(&sensor);
    APP_ERROR_CHECK(rslt);
    
    
    int8_t Acc_i2c_Write(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
{

    //  NRF_LOG_INFO("WRITE: dev_id: %x reg_addr: %x reg_data: %x len: %i\n", dev_id, reg_addr, *reg_data, len);
	//int8_t rslt = 0;
	uint8_t data[len + 1];
	data[0] = reg_addr;
	for (uint16_t i = 0; i < len; i++) {
		data[i + 1] = reg_data[i];
	}
	
	rsltw = nrf_drv_twi_tx(&m_twi, dev_id, data, len + 1, false);
	APP_ERROR_CHECK(rsltw);
        return rsltw;
  
}


int8_t Acc_i2c_Read(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
{
	//int8_t rslt = 0;
   //     NRF_LOG_INFO("READ: dev_id: %x reg_addr: %x len: %i\n", dev_id, reg_addr, len);
	rsltr = nrf_drv_twi_tx(&m_twi, dev_id, &reg_addr, 1, true);
        APP_ERROR_CHECK(rsltr);

	if (rsltr == 0)
	{
		rsltr = nrf_drv_twi_rx(&m_twi, dev_id, reg_data, len);
	}
    //    NRF_LOG_INFO("READ: %x",*reg_data);
	return rsltr;
}


      length1 = sprintf(str, "DataX = %5d \n", accel.x);

      rsltb = ble_nus_data_send(&m_nus, str, &length1, m_conn_handle);
     // APP_ERROR_CHECK(rsltb);

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Wed, 31 Oct 2018 15:13:48 GMT

Actually the fatal error is not constant

It was came when I disturb the sensor as same like above return err code 0x01
Some other time while I not connect to phone that ble_data_nus_send() returns 0x05 and within few seconds cause fatal error

And definitely I need low power required

Is it possible that whenever I need that time I can able to initialize the ble?.

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Wed, 31 Oct 2018 12:26:14 GMT

Unless you have very low power requirements, I would recommend that you stay in the connection all the time to make sure there is not a lot of overhead when sending the data. You can then implement a button handler that send the data using ble_nus_data_send when the button is pressed.

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Wed, 31 Oct 2018 12:23:50 GMT

What function returns 0x05? That error number normally means NRF_ERROR_NOT_FOUND.

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Wed, 31 Oct 2018 12:14:29 GMT

Can I use button 1 to on/off the Bluetooth is it possible?

The controller can do its work by fetching the data from sensor

if the button is pressed controller send the respective data to BLE UART otherwise the controller do their work

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Wed, 31 Oct 2018 11:24:02 GMT

it returns 0X05

RE: BMI160 + NRF52832 + I2C

Jørgen Holmefjord — Wed, 31 Oct 2018 09:18:48 GMT

There is an error code returned from a function call in your Acc_i2c_Read function. Please compile and run the code as Debug instead of Release mode. Please check which function is returning the error and what error code is returned.

RE: BMI160 + NRF52832 + I2C

Sunil vignesh — Wed, 31 Oct 2018 05:33:54 GMT

i thought

Is this because of sensor which i connected is not properly connect or any bug in the code itself..?