BLE_GAP_EVT_ADV_REPORT missing complete local name?

[bfriedk1]

Hello -

This is a strange problem and I'm guessing I am missing something obvious. I am using the sd_ble_gap_scan_start() API to perform active scanning as follows:

	ble_gap_scan_params_t scan_params;

	gBLE->adv_report_buffer.len = sizeof(gBLE->adv_data);
	gBLE->adv_report_buffer.p_data = &gBLE->adv_data[0];
	
	c_memset(&scan_params, 0, sizeof(scan_params));
	scan_params.active = 1;
	scan_params.filter_policy = BLE_GAP_SCAN_FP_ACCEPT_ALL;
	scan_params.interval = interval;
	scan_params.window = window;

	err_code = sd_ble_gap_scan_start(&scan_params, &gBLE->adv_report_buffer);

The length of the advertising report data buffer is set to BLE_GAP_SCAN_BUFFER_MAX. In my GAP event handler, I receive the BLE_GAP_EVT_ADV_REPORT events and the associated report data record:

switch (p_ble_evt->header.evt_id)
{
case BLE_GAP_EVT_ADV_REPORT: {
ble_gap_evt_adv_report_t const * p_evt_adv_report = &p_ble_evt->evt.gap_evt.params.adv_report;

When I examine the bytes in p_evt_adv_report->data.p_data, there are no device name fields in the advertisement/scan response data. The p_evt_adv_report->data.len field value seems viable. I know I have multiple peripheral devices advertising their complete local names. I can see them in LightBlue and various other mobile BLE scanning apps. In my code I do follow-up and restart scanning after each BLE_GAP_EVT_ADV_REPORT event:

		sd_ble_gap_scan_start(NULL, &gBLE->adv_report_buffer);

Is there a configuration/initialization option I am missing that would lead to this behavior?

I am running this code on the nRF52840 DK under FreeRTOS.

Regards,

Brian

 

[bfriedk1]

Hello -

I forgot to note that the scan window and interval values are basically the NRF_BLE_SCAN_SCAN_INTERVAL and NRF_BLE_SCAN_SCAN_WINDOW values.

- Brian

[Edvin]

Hello Brian,

I am not sure what SDK version you use, so but the names used here are from SDK15.3.0. Hence, some variable names may be a bit different in your SDK if you are not using 15.3.0.

I suspect one of the following:

Either you are picking up the advertising data from another device. Are you sure the advertising packet is coming from your peripheral?

Another possibility is that you are monitoring the raw data, and the name is not in the start of the advertising packet and/or you expect it to look different. What does your advertising data in the scan response look like?

One last possibility may be that the advertising data is in the scan_response advertising packet. Are you picking up any scan response packets? Is:

p_ble_evt->evt.gap_evt.params.adv_report.type.scan_response == 0 or 1?

If you set a breakpoint in the first advertising packet you get, you will never receive the scan response. Make sure to only set the breakpoint if p_ble_evt->evt.gap_evt.params.adv_report.type.scan_response == 1, if you want to check the scan response.

Best regards,

Edvin

[bfriedk1]

Edvin -

Thank you for the follow-up. I appreciate your suggestions and insights. I am using the S140 SoftDevice API v6.1.1 and the 15.3.0 SDK.

After trying a few more configuration variations using sd_ble_gap_scan_start() without any luck, I switched over to nrf_ble_scan_init() and nrf_ble_scan_start(). That worked well and the advertising reports have all the expected data. Since nrf_ble_scan_start() ultimately calls sd_ble_gap_scan_start(), my guess is that I wasn't setting up the buffers and/or connection parameters correctly when calling sd_ble_gap_scan_start() directly. In any case, the nrf_ APIs are used in the example apps and are easy enough to configure. 

Thanks again.

Regards,

Brian