Sending actual TWI sensor values through BLE

[KCY]

Hello! I am trying to modify the ble_app_hrs_freertos example to send actual heart rate sensor value to the nRF Toolbox app over BLE. I am able to read values from my sensor through TWI, and I am also able to run the ble_app_hrs_freertos example and send the simulated data through BLE. Now, I would like to combine the two, and send the actual reading from the sensor to the app through BLE.

I tried modifying the heart_rate_meas_timeout_handler function of the code to take value from the sensor instead of sensorsim_measure(). However when I do this, I am not able to the device anymore. After trying different things, I realized that the nrf_drv_twi_tx() and nrf_drv_twi_rx() function is the issue. My I wrong to call nrf_drv_twi_tx() and nrf_drv_twi_rx() in the handler? How then, can I get the sensor reading through TWI?

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static void heart_rate_meas_timeout_handler(TimerHandle_t xTimer)

{

static uint32_t cnt = 0;

ret_code_t err_code;

uint8_t heart_rate;

UNUSED_PARAMETER(xTimer);

//heart_rate = (uint16_t)sensorsim_measure(&m_heart_rate_sim_state, &m_heart_rate_sim_cfg);

heart_rate = readHRS();

cnt++;

err_code = ble_hrs_heart_rate_measurement_send(&m_hrs, heart_rate);

if ((err_code != NRF_SUCCESS) &&

(err_code != NRF_ERROR_INVALID_STATE) &&

(err_code != NRF_ERROR_RESOURCES) &&

(err_code != NRF_ERROR_BUSY) &&

(err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)

)

{

APP_ERROR_HANDLER(err_code);

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static void heart_rate_meas_timeout_handler(TimerHandle_t xTimer)
{
    static uint32_t cnt = 0;
    ret_code_t      err_code;
    uint8_t        heart_rate;

    UNUSED_PARAMETER(xTimer);

    //heart_rate = (uint16_t)sensorsim_measure(&m_heart_rate_sim_state, &m_heart_rate_sim_cfg);
    heart_rate = readHRS();
    
    cnt++;
    err_code = ble_hrs_heart_rate_measurement_send(&m_hrs, heart_rate);
    if ((err_code != NRF_SUCCESS) &&
        (err_code != NRF_ERROR_INVALID_STATE) &&
        (err_code != NRF_ERROR_RESOURCES) &&
        (err_code != NRF_ERROR_BUSY) &&
        (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
       )
    {
        APP_ERROR_HANDLER(err_code);
    }

    // Disable RR Interval recording every third heart rate measurement.
    // NOTE: An application will normally not do this. It is done here just for testing generation
    // of messages without RR Interval measurements.
    m_rr_interval_enabled = ((cnt % 3) != 0);
}


void readHRS(uint8_t * read_long_data){
    ret_code_t err_code;
    
    err_code = nrf_drv_twi_tx(&m_twi_nrf52, HRS_ADDR, (uint8_t *) HRS_FIFO_DATA, sizeof(HRS_FIFO_DATA), true);

    if (NRF_SUCCESS == err_code){
	    err_code = nrf_drv_twi_rx(&m_twi_nrf52, HRS_ADDR, (uint8_t *) read_long_data, 6);
    }
    APP_ERROR_CHECK(err_code);
    nrf_delay_ms(10);
}

THANK YOU!