Advertising doesn't start immediately after calling sd_ble_gap_adv_start

RE: Advertising doesn't start immediately after calling sd_ble_gap_adv_start

Fabian Hauschild — Mon, 09 Dec 2019 13:47:53 GMT

I tried starting the Advertising with 100ms 50ms and 20ms interval but that doesn't change anything.

It still takes up to 10s until I can see the Advertising with the nrf Connect App

RE: Advertising doesn't start immediately after calling sd_ble_gap_adv_start

Fabian Hauschild — Thu, 28 Nov 2019 15:58:18 GMT

Thanks for the answer.

After the Disconnect I start the Advertsing with an interval of 500ms and a timeout of 30s.

I'm using the same function to start advertising after a reset / power on.

I don't use fast or slow advertising I've written my own advertising functions to init, start and stop advertising via the SoftDevice API.

This code is part of my function to init and start advertising. It is called after disconnecgt and after reset.

Advertising Data is the Devicename and Manufaturer Specific Data (Scan Response).

 // Those are the Parameters used for advertising
 
 // --- Set advertising Parameters ---------
 memset(&adv_params,0,sizeof(adv_params));
 
 adv_params.primary_phy     = BLE_GAP_PHY_1MBPS;
 adv_params.duration        = APP_ADV_TIMEOUT_IN_SECONDS;  // 30s
 adv_params.properties.type = BLE_GAP_ADV_TYPE_CONNECTABLE_SCANNABLE_UNDIRECTED;
 adv_params.p_peer_addr     = NULL;
 adv_params.filter_policy   = BLE_GAP_ADV_FP_ANY;
 adv_params.interval        = 5 * 160;             // ca 500ms
 
 // --- Update Advertising data & parameter --------
err_code = 0;
err_code = sd_ble_gap_adv_set_configure(&m_adv_handle,&m_adv_data,&adv_params);    
err_code++;

// --- Start Advertiding
err_code = sd_ble_gap_adv_start(m_adv_handle, APP_BLE_CONN_CFG_TAG);
NRF_LOG_INFO("Advertising started err_code: %d", err_code);

RE: Advertising doesn't start immediately after calling sd_ble_gap_adv_start

run_ar — Thu, 28 Nov 2019 12:44:09 GMT

We usually use the ble sniffer from ellisys if we do not use the nrfsniffer. There are other options, i.e. frontline, but this is not as intuitive as the ellisys sniffer, mainly because the gui is a bit dated.

With 500ms adv interval it will take some time to establish the connection. After a disconnect the advertisement module would usually start fast advertising, then move to slow after some time. This could also be done on startup. i.e. configure the device to start fast advertising for a few secondes before changing to a slower more power conserving interval later.

RE: Advertising doesn't start immediately after calling sd_ble_gap_adv_start

Fabian Hauschild — Wed, 27 Nov 2019 10:22:39 GMT

Hi,

I've checked the advertising with a sniffer. After a disconnect the advertising starts immediatly.

After a power up it takes up to 10 seconds until I can see advertising packets with the sniffer. (The application starts advertising 3s after power on).

Can you recommend a good Bluetooth / BLE sniffer ?

RE: Advertising doesn't start immediately after calling sd_ble_gap_adv_start

Fabian Hauschild — Tue, 26 Nov 2019 12:25:28 GMT

Hi,

I'm using a 500ms advertising interval.

I don't have access to a BLE Sniffer (I could try using nRF Sniffer with a nRF52840 DK. But itwill take some time setting this up)

We have been testing our BLE products with nrfConnect for Android and PC.

RE: Advertising doesn't start immediately after calling sd_ble_gap_adv_start

run_ar — Tue, 26 Nov 2019 12:10:59 GMT

Hi,

What advertisement interval are you using? Could you check with a sniffer when the first advertisement package is sent on air?

Note that in case the advertiser and scanner interval uses similar intervals, it could take some time until the scanner captures the advertisement packet.