ble advertising start probelm

[Fiske]

In my application, I execute below code to start advertise when a button is pressed

                        err_code = ble_advertising_start(BLE_ADV_MODE_FAST);
                        APP_ERROR_CHECK(err_code);

When I press the button for more than once, the system reset. It seems that when I execute above code when the advertising has already started, the system will reset. Can you tell me how to solve it. One of the possible ways is to check the advertise status, if it has already started, above code will not executed. Please tell me how to check the advertise is started or not. Please also advise other methods if you have.

[Jørgen Holmefjord]

Hi,

As described in this answer, there is no way of checking the current state of advertising. You should implement a flag in your application where you keep track of whether you are advertising or not.

If you have a connectable peripheral with two buttons, one for starting and one for stopping advertisingcould, an example could be like this:

bool is_advertising = false;

void button_1_handler(void) // Start advertising
{
	if(!is_advertising)
	{
		err_code = sd_ble_gap_adv_start();
		if (err_code == NRF_SUCCESS){
			is_advertising = true;
		}
		else{
			APP_ERROR_CHECK(err_code);
		}
	}
}

void button_2_handler(void) // Stop advertising
{
	if(is_advertising)
	{
		err_code = sd_ble_gap_adv_stop();
		if (err_code == NRF_SUCCESS){
			is_advertising = false;
		}
		else{
			APP_ERROR_CHECK(err_code);
		}
	}
}

static void on_ble_evt(ble_evt_t * p_ble_evt)
{
    uint32_t err_code;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
			is_advertising = false; // Softdevice stops advertising when in a connection
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            if(!is_advertising)
			{
				err_code = sd_ble_gap_adv_start(); // Start advertising when no longer connected
				if(err_code == NRF_SUCCESS){
					is_advertising = true;
				}
				else{
					APP_ERROR_CHECK(err_code);
				}
			}
            break;

        case BLE_GAP_EVT_TIMEOUT:
            if (p_ble_evt->evt.gap_evt.params.timeout.src == BLE_GAP_TIMEOUT_SRC_ADVERTISING)
			{
				is_advertising = false; // If advertising times out
			}
            break;
	}
}

Remember that you need to keep track of the advertising state if you start or stop advertising elsewhere in your code.

Best regards,

Jørgen

[Fiske]

When I compile the code, it generate below error at if (p_ble_evt->evt.gap_evt.timeout.src == BLE_GAP_TIMEOUT_SRC_ADVERTISING). Note that I am using nRF5_SDK_12.0.0 ble_app_uart example

Error[Pe136]: struct "" has no field "timeout"

Besides, why the answer post at here is different from the one shown in my email.

in my email the event case is case BLE_GATTC_EVT_TIMEOUT:

while at the web page it is case BLE_GAP_EVT_TIMEOUT:

[Jørgen Holmefjord]

I'm sorry, there was a typo in the code. It should be: p_ble_evt->evt.gap_evt.params.timeout.src. I updated the code after posting the original reply (you can click the updated [time] on the answer to see changelog), maybe you did not get an update mail.

[Joao Teixeira]

Please, take also a look in the answer posted here.