Advertising and scanning on single channel

[Tejal Jagdale]

Hello,

I am using NRF52832, SDK v15.1.0.

For advertising on single channel, I added  " p_advertising->adv_params.channel_mask[4] = 03; "  in  ble_advertising_start() , yet it doesn't work.

Also, is it possible to do scanning with selective channel?

I have gone through previous blogs related this, but it doesn't work.

Is there any other way of doing this?

[AndreasF]

Hi Tejal.

First, we have a new SDK version out, SDK v15.2.0, I really recommend that you download that here!

If you want to advertise on a single channel, you can indeed turn of the other two channels.

adv_params.channel_mask[4] = 0x80; // Dont advertise on ch 39
adv_params.channel_mask[4] = 0x40; // Dont advertise on ch 38
adv_params.channel_mask[4] = 0x20; // Dont advertise on ch 37


adv_params.channel_mask[4] = 0xA0; // Dont advertise on ch 39 and 37
adv_params.channel_mask[4] = 0xC0; // Dont advertise on ch 38 and 39
adv_params.channel_mask[4] = 0x60; // Dont advertise on ch 37 and 38

Just add ONE of these channel masks, depending on which channel(s) you would like to turn off, before the following:

    err_code = sd_ble_gap_adv_set_configure(&m_adv_handle, &m_adv_data, &adv_params);
    APP_ERROR_CHECK(err_code);
}

In static void advertising_init(void), my advertising_init(void) looks like this when I've masked channel 39:

static void advertising_init(void)
{
    ret_code_t    err_code;
    ble_advdata_t advdata;
    ble_advdata_t srdata;

    ble_uuid_t adv_uuids[] = {{LBS_UUID_SERVICE, m_lbs.uuid_type}};

    // Build and set advertising data.
    memset(&advdata, 0, sizeof(advdata));

    advdata.name_type          = BLE_ADVDATA_FULL_NAME;
    advdata.include_appearance = true;
    advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;


    memset(&srdata, 0, sizeof(srdata));
    srdata.uuids_complete.uuid_cnt = sizeof(adv_uuids) / sizeof(adv_uuids[0]);
    srdata.uuids_complete.p_uuids  = adv_uuids;

    err_code = ble_advdata_encode(&advdata, m_adv_data.adv_data.p_data, &m_adv_data.adv_data.len);
    APP_ERROR_CHECK(err_code);

    err_code = ble_advdata_encode(&srdata, m_adv_data.scan_rsp_data.p_data, &m_adv_data.scan_rsp_data.len);
    APP_ERROR_CHECK(err_code);

    ble_gap_adv_params_t adv_params;

    // Set advertising parameters.
    memset(&adv_params, 0, sizeof(adv_params));

    adv_params.primary_phy     = BLE_GAP_PHY_1MBPS;
    adv_params.duration        = APP_ADV_DURATION;
    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        = APP_ADV_INTERVAL;
    adv_params.channel_mask[4] = 0x80; //The code added to mask channel 39

    err_code = sd_ble_gap_adv_set_configure(&m_adv_handle, &m_adv_data, &adv_params);
    APP_ERROR_CHECK(err_code);
}

All this is done in the nRF5_SDK_15.2.0_9412b96\examples\ble_peripheral\ble_app_blinky example project.

If you want to scan a single channel I suggest you take a look at this post, where this is explained.

Good luck.

- Andreas

[Tejal Jagdale]

It is working. Thanks for your help !