NRF52 reconnection problem

RE: NRF52 reconnection problem

Chocol8 — Wed, 07 Mar 2018 07:08:20 GMT

Thanks to Edvin problem was solved. He found out that by default, a variable is set in advertising init. There is a parameter called: init.config.ble_adv_in_disconnect_disabled which is set to false (0) by default. In ble_advertising.c there is an advertising event handler called ble_advertising_on_ble_evt() which is called in parallel with the eventhandler in main.c.

The event handler in ble_advertising.c has the following:

 // Upon disconnection, whitelist will be activated and direct advertising is started.
        case BLE_GAP_EVT_DISCONNECTED:
            on_disconnected(p_advertising, p_ble_evt);
            break;

Inside on_disconnected(...) it will call ble_advertising_start() if (p_advertising->adv_modes_config.ble_adv_on_disconnect_disabled == false) :

    if (p_ble_evt->evt.gap_evt.conn_handle == p_advertising->current_slave_link_conn_handle &&
        p_advertising->adv_modes_config.ble_adv_on_disconnect_disabled == false)
    {
       ret = ble_advertising_start(p_advertising, BLE_ADV_MODE_DIRECTED);
       if ((ret != NRF_SUCCESS) && (p_advertising->error_handler != NULL))
       {
           p_advertising->error_handler(ret);
       }
    }

Since this is called at once when the disconnect happened, it would always be called before the timer from main decided to start advertising.

To solve this Edvin suggested to start advertising right after disconnection or to change ble_adv_on_disconnect_disabled in the advertising_init() function. Then advertising_init() looks like this:

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_TIMEOUT_IN_SECONDS;
    
    init.config.ble_adv_on_disconnect_disabled = true;

    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);
}

RE: NRF52 reconnection problem

Chocol8 — Tue, 06 Mar 2018 12:05:00 GMT

Yes, you are correct, ble_advertising_init() is used once. Ok, I will do this.

Best regards

RE: NRF52 reconnection problem

Edvin — Tue, 06 Mar 2018 12:01:35 GMT

And you only use ble_advertising_init() once? Yes. You could do that. It would be great if you link to this case in the private case, so that I can pick it up.

Best regards,

Edvin

RE: NRF52 reconnection problem

Chocol8 — Tue, 06 Mar 2018 11:43:40 GMT

Thank you for suggestions. m_advertising is defined only in main.c like this: BLE_ADVERTISING_DEF(m_advertising);

Function err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
APP_ERROR_CHECK(err_code); is being used only in main() function.

Would it be easier if I upload it to a private case study?

Best regards

RE: NRF52 reconnection problem

Edvin — Tue, 06 Mar 2018 10:37:00 GMT

Hello,

Ok, so the function ble_advertising_start() returns 8 [NRF_ERROR_INVALID_STATE].

The app_timer_stop_all() function does not seem to stop the timer that the softdevice uses, only the ones used in app_timer, so that should not be the problem. I tried to use app_timer_stop_all() right before ble_advertising_start(), and that works fine.

NRF_ERROR_INVALID_STATE usually indicates that ble_advertising_init() has not been called before the ble_advertising_start() function. Since you are able to start advertising before the connection, this is obviously not the case here. Have you changed anything in your m_advertising variable while being in the connection?

It is a bit difficult to say only from the code snippets, but is the ble_advertising_start() that is called and returns the error the one in your main() function, or is it called from somewhere else? Maybe it is being called twice?

Best regards,

Edvin

RE: NRF52 reconnection problem

Chocol8 — Mon, 05 Mar 2018 14:45:25 GMT

Thank you for taking time to investigate my problem. I have deleted few line of code that is why RTT shows error in main.c 1418. This is the same error that occurs at 1416. They both bring this to RTT: <error> app: ERROR 8 [NRF_ERROR_INVALID_STATE] at ..\..\..\main.c:1418

Moreover, I have tried to change app_timer_stop_all(); to just one timer that I use. This change have not solved my problem.

I have tried your proposal to use:

err_code = app_timer_stop_all();
APP_ERROR_CHECK(err_code);

The result is same as it was before. RTT says that error stems from main.c 1418.

RE: NRF52 reconnection problem

Edvin — Mon, 05 Mar 2018 14:12:42 GMT

Hello,

I think you posted the wrong screenshot after:

"This is the error I receive in J-link RTT viewer"

Can you please try to check the return on app_timer_stop_all();

err_code = app_timer_stop_all();
APP_ERROR:CHECK(err_code);

Aslo, what is the RTT printing on line 1416 in main?

Best regards,

Edvin