Address filter not match issue in BLE scanning

[Kawing]

Hi Nordic, 

I am working on project with nrf52840 , which is a central to connect other device. we will enter the MAC address to central, and setup the scaning filter.

the central device is development with SoftDevice nRF5_SDK_17.0.0_9d13099.

so far the function is work , but we found a issue now, the address filter cannot return match result. 

following is the code which is initial the scanning and the filter. 

/**@brief Function for initialization scanning and setting filters.
 */
static void scan_init(uint8_t *target_MAC)
{
    ret_code_t          err_code;
    nrf_ble_scan_init_t init_scan;
    uint8_t u8_filter_mode = 0x00;

    memset(&init_scan, 0, sizeof(init_scan));

    init_scan.p_scan_param     = &m_scan_param;
    init_scan.connect_if_match = false;
    init_scan.conn_cfg_tag     = APP_BLE_CONN_CFG_TAG;

    err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
    APP_ERROR_CHECK(err_code);


    if(NRF_BLE_SCAN_ADDRESS_CNT >0){
        ble_gap_addr_t st_target_periph_addr ={
            .addr_type = BLE_GAP_ADDR_TYPE_RANDOM_STATIC,
            .addr = {0}
        };

        memcpy(st_target_periph_addr.addr, target_MAC, 6);
        NRF_LOG_HEXDUMP_INFO(st_target_periph_addr.addr,6);

        /// MAC address filter
        err_code = nrf_ble_scan_filter_set(&m_scan,SCAN_ADDR_FILTER,st_target_periph_addr.addr);
        APP_ERROR_CHECK(err_code);

        u8_filter_mode |= NRF_BLE_SCAN_ADDR_FILTER;
    }

    if (NRF_BLE_SCAN_UUID_CNT > 0){
        ble_uuid_t uuid =
        {
            .uuid = TARGET_UUID,
            .type = BLE_UUID_TYPE_BLE,
        };
        
        // UUID filter 
        err_code = nrf_ble_scan_filter_set(&m_scan,SCAN_UUID_FILTER,&uuid);
        APP_ERROR_CHECK(err_code);
    
        u8_filter_mode |= NRF_BLE_SCAN_UUID_FILTER;
    }
    
    err_code = nrf_ble_scan_filters_enable(&m_scan,u8_filter_mode,false);
    APP_ERROR_CHECK(err_code);

}

and I checked the event case "NRF_BLE_SCAN_EVT_NOT_FOUND" content, the central can found the device , just the  MAC address not match. 

do you have any suggestion for how to create a correct scanning filter.

 

Thanks

[Amanda Hsieh]

Hi, 

Do you set the target address correct order? See this post. 

Regards, 

Amanda

[Kawing]

Hi Amanada, 

Thanks for your reply.

I checked the address ordering are correct. Acturally , I have few same device, they have difference mac address only, half of them can report in all match case. but another just report as UUID match only. Address filter show not match. 

[Amanda Hsieh]

Hi, 

Kawing said:

but another just report as UUID match only. Address filter show not match. 

What is the address type of those devices?  Are they random static addresses? How do you check the advertising mac address? Are you able to check their mac addresses by sniffer? Is it the same as you set for the filter? 

-Amanda H.

[Kawing]

Hi, 

how to add the address type in the filter?  since I tried to change the variable to BLE_GAP_ADDR_TYPE_PUBLIC ,but there is same result.

     ble_gap_addr_t st_target_periph_addr ={
            .addr_type = BLE_GAP_ADDR_TYPE_PUBLIC,
            .addr = {0}
        };

[Amanda Hsieh]

What is the mac address? You cannot set the address as .addr = {0}. 

You should know what is the address type of the peripheral device using. Please check the advertising address and type with the sniffer. 

-Amanda H.

[Kawing]

hi Amanda , 

the good examples address is 7C:9E:BD:CC:08:02 

and the cannot match example is 34:AB:95:49:4B:62 

I cannot make sure all devices are using the same type. even I wanted to chang the scanning address type . I don't know how to change it , please suggest how to adding the address type in the filter by using the Software device API , thanks.