How to get the scan response datafor the center?

RE: How to get the scan response datafor the center?

Einar Thorsrud — Wed, 19 Sep 2018 08:47:40 GMT

Hi,

S132 version 6.0 and version 6.1 should behave the same in this regard, and both work as they should on my desk. I have updated my previous post to print data and included example projects for both SDK 15.0.0 and SDK 15.2.0 so that you can test both.

Note that a BLE peripheral will typically reply with an empty scan response if no scan response has been configured. So empty scan responses are expected (though not from a peripheral you know has scan response data). Perhaps you could log the BLE address of the advertiser to verify whether the empty scan responses come from your peripheral (where there should be scan response data) or not? You could for example do something like this:

            NRF_LOG_INFO("Peer addr: %02x:%02x:%02x:%02x:%02x:%02x.",
                         p_adv_report->peer_addr.addr[5],
                         p_adv_report->peer_addr.addr[4],
                         p_adv_report->peer_addr.addr[3],
                         p_adv_report->peer_addr.addr[2],
                         p_adv_report->peer_addr.addr[1],
                         p_adv_report->peer_addr.addr[0]);

RE: How to get the scan response datafor the center?

Alice — Tue, 18 Sep 2018 11:27:17 GMT

I use the scanner to work on sdk15.2 and S132v6.1, I could get the scan response data. However, I if I use the same way to make the scanner to work on sdk 15.0 and S132v6.0,then scan the same advertiser, I could see that the bit scan_response of ble_gap_adv_report_type_t is 1, but I just get the advertising data, I couldn't get the scan_response data.

Is there any problem with s132v6.0? Could you help me have a try? Thanks

RE: How to get the scan response datafor the center?

Einar Thorsrud — Mon, 17 Sep 2018 13:02:04 GMT

I don't see any problems with your code, neither the scanner nor the advertiser.

For reference (and if you would like to test with a known working example), I stripped down a central project to only do active scanning and logging whether an advertisement packet or scan response packet was received. The two relevant functions are here:

static void scan_start(void)
{
    ret_code_t ret;

    m_scan_param.active         = 1;
    m_scan_param.interval       = SCAN_INTERVAL;
    m_scan_param.window         = SCAN_WINDOW;
    m_scan_param.timeout        = SCAN_DURATION;
    m_scan_param.scan_phys      = BLE_GAP_PHY_1MBPS;
    m_scan_param.filter_policy  = BLE_GAP_SCAN_FP_ACCEPT_ALL;

    ret = sd_ble_gap_scan_start(&m_scan_param, &m_scan_buffer);
    APP_ERROR_CHECK(ret);
}

static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    ret_code_t            err_code;
    ble_gap_evt_adv_report_t const * p_adv_report = &p_ble_evt->evt.gap_evt.params.adv_report;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_ADV_REPORT:

            if (p_adv_report->type.scan_response)
            {
                if (p_adv_report->data.len > 0)
                {
                    NRF_LOG_INFO("Scan response received:");
                    NRF_LOG_RAW_HEXDUMP_INFO(p_adv_report->data.p_data, p_adv_report->data.len);
                }
                else
                {
                    NRF_LOG_INFO("Empty scan response received.");
                }
            }
            else
            {
                NRF_LOG_INFO("Advertising packet received:");
                NRF_LOG_RAW_HEXDUMP_INFO(p_adv_report->data.p_data, p_adv_report->data.len);
            }

            // Continue scanning.
            sd_ble_gap_scan_start(NULL, &m_scan_buffer);
            break;
        default:
            break;
    }
}

Here are full projects for SDK 15.0 (devzone.nordicsemi.com/.../ble_5F00_active_5F00_scanner_5F00_sdk_5F00_15.0.zip) and SDK 15.2 (devzone.nordicsemi.com/.../ble_5F00_active_5F00_scanner_5F00_sdk_5F005F00_15.2.zip).

RE: How to get the scan response datafor the center?

Alice — Mon, 17 Sep 2018 09:56:59 GMT

devzone.nordicsemi.com/.../6087.code.txt

This is the code for the ble_advertising_init and the scan report.

RE: How to get the scan response datafor the center?

Einar Thorsrud — Mon, 17 Sep 2018 09:11:18 GMT

You should not have to do anything more. Can you upload the code for your advertiser and scanner?

RE: How to get the scan response datafor the center?

Alice — Mon, 17 Sep 2018 08:01:54 GMT

Yes, I'm sure about it.

RE: How to get the scan response datafor the center?

Einar Thorsrud — Thu, 13 Sep 2018 11:46:08 GMT

That's strange. Have you made sure to configure the peripheral so that it has scan response data (essentially just populate ble_advertising_init_t::srdata)?

RE: How to get the scan response datafor the center?

Alice — Thu, 13 Sep 2018 08:14:05 GMT

Does S132v6.0 could do it? I have set the active field of the ble_gap_scan_params_t instance to 1, but I couldn't get the scan response data. The bit scan_response of ble_gap_adv_report_type_t is always 0.

RE: How to get the scan response datafor the center?

Einar Thorsrud — Fri, 07 Sep 2018 08:36:35 GMT

Hi,

You have to do active scanning in order to get the scan response. To do that, simply set the active field of the ble_gap_scan_params_t instance to 1 before you pass it in the call to sd_ble_gap_scan_start(). Then you will get the scan response data in a BLE_GAP_EVT_ADV_REPORT event in the same way as you get normal advertising data. You can see which type it is by checking the type field in the ble_gap_evt_adv_report_t.