Large data transfer [nRF5 SDK v. 11, nRF52-DK, BLE]

[Pawel J]

Dear Forum Users,

I am trying to send the data in a burst. Thanks to this post I have managed to achieve ~2,5 kB/s. However this lasts only for few seconds. Then the stream is 4 packets long after which occurs a short break. This happens cyclically from then on and results in transfer drop to 80-160 B/s.

Could this be caused by the fact of using different SDK? Why is it so and how can it be improved?

The sending function heart_rate_meas_timeout_handler in nRF5 DK is a timer handler, so I stop the timer using app_timer_stop(). I have noticed that stopping battery_level_meas also causes the system working slowly.

Thank you for your help!

static void heart_rate_meas_timeout_handler(void )
{
    static uint32_t cnt = 0;
    uint32_t        err_code;
    uint16_t        heart_rate;

    err_code = app_timer_stop(m_heart_rate_timer_id);
    APP_ERROR_CHECK(err_code);

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

while(true)
{
    if (cnt < 300)
    {

    err_code = ble_hrs_heart_rate_measurement_send(&m_hrs, cnt);
    if (err_code == BLE_ERROR_NO_TX_PACKETS ||
        err_code == NRF_ERROR_INVALID_STATE ||
        err_code == BLE_ERROR_GATTS_SYS_ATTR_MISSING)
    {
        break;
    }
    else if (err_code != NRF_SUCCESS)
    {
        APP_ERROR_HANDLER(err_code);
    }

    cnt++;
}

in on_ble_evt():

 case BLE_EVT_TX_COMPLETE:
      heart_rate_meas_timeout_handler();
      break;

[Anders Strand]

do you have a nRF51 you can set up as an nRF sniffer?. If not, add some printing which can tell us the connection parameters being set on EVT_CONNE and on the BLE_GAP_EVT_CONN_PARAM_UPDATE event. (Check on_conn_params_update() in ble_conn_params.c or catch the event in main.c. This sound like connection parameters being updated