BMI160 + NRF52832 + I2C

[Sunil vignesh]

HI,

I want to develop a program to access Accelerometer and gyroscope value from BMI160 sensor. I have used this BMI160 library 

I alter the TWI_SENSOR code and it works for self testing ACC code. but i need to calibrate the x, y, z axis value and i want to add BLE stack to read in mobile app.

1. How to collect all the X,Y,Z axis value

2. i need to see the LOGS in Bluetooth app by using BLE_UART. how to edit the BLE_UART code to get the respective ACC and GYRO value in BLE APP.

Is there any code for reading X,Y,Z axis for BMI160??

[Jørgen Holmefjord]

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.

[Sunil vignesh]

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.?

[Jørgen Holmefjord]

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).

[Sunil vignesh]

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);
}

[Jørgen Holmefjord]

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

[Sunil vignesh]

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