Whitelisting in Gatt Server mode (SDK 15.2 /nrf52840)

[preethi16]

Im using sdk 15.2 with 2 nrf52840 boards, i would like the server to connect to a particular client. How to add the devices to whitelist in sdk 15.2 ?. I have gone through various blogs and  I have used the following snippet, but the server connects to any client available in the vicinity. Please do correct me if im wrong .

ble_gap_addr_t whitelist_addr = {1, BLE_GAP_ADDR_TYPE_PUBLIC,{0x27,0x23,0xBC,0x70,0xF2,0xDC}};
ble_gap_addr_t const *p_whitelist_addr[] = {&whitelist_addr};

ret_code_t err_code;
err_code = sd_ble_gap_whitelist_set(p_whitelist_addr, 1);
if (err_code==NRF_SUCCESS)
{
NRF_LOG_INFO("wHITELIST SET SUCCESSFULLY ");
}
APP_ERROR_CHECK(err_code);

thanks,

Preethi

[Simon]

I managed to make it work using respectively \nRF5_SDK_15.2.0\examples\ble_peripheral\ble_app_uart and nRF5_SDK_15.2.0\examples\ble_central\ble_app_uart_c. 

• In ble_app_uart_c/main.c I figured out the address and address type by using sd_ble_gap_addr_get():

ret_code_t err_code;
    ble_gap_addr_t mac_addr;
    err_code = sd_ble_gap_addr_get(&mac_addr); 
    APP_ERROR_CHECK(err_code);

    if(BLE_GAP_ADDR_TYPE_PUBLIC == mac_addr.addr_type){
        NRF_LOG_INFO("Address type is BLE_GAP_ADDR_TYPE_PUBLIC");
    }else if(BLE_GAP_ADDR_TYPE_RANDOM_STATIC == mac_addr.addr_type){
        NRF_LOG_INFO("Address type is BLE_GAP_ADDR_TYPE_RANDOM_STATIC");
    } else if(BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_RESOLVABLE == mac_addr.addr_type){
        NRF_LOG_INFO("Address type is BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_RESOLVABLE");
    } else if(BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_NON_RESOLVABLE == mac_addr.addr_type){
        NRF_LOG_INFO("Address type is BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_NON_RESOLVABLE");
    } else if(BLE_GAP_ADDR_TYPE_ANONYMOUS == mac_addr.addr_type){
        NRF_LOG_INFO("Address type is BLE_GAP_ADDR_TYPE_ANONYMOUS");
    }
    
    NRF_LOG_INFO("Address: [%X, %X, %X, %X, %X, %X]", mac_addr.addr[0], mac_addr.addr[1], mac_addr.addr[2], mac_addr.addr[3], mac_addr.addr[4], mac_addr.addr[5]);

• I got the following log:

Address type is BLE_GAP_ADDR_TYPE_RANDOM_STATIC
<info> app: Address: [D3, EA, 17, FD, E8, FB]

In ble_app_uart/main.c I made the following changes:

• In main.c --> advertising_init() I added the following:

init.config.ble_adv_whitelist_enabled = true;

• In the top of main.c -->on_adv_evt() I added the following:

ble_gap_addr_t whitelist_addr = {1, BLE_GAP_ADDR_TYPE_RANDOM_STATIC, {0xD3, 0xEA, 0x17, 0xFD, 0xE8, 0xFB}};
ble_gap_addr_t const     *p_whitelist_addr[] = {&whitelist_addr};

• In  main.c -->on_adv_evt() I added a new case:

        case BLE_ADV_EVT_WHITELIST_REQUEST:
            err_code = sd_ble_gap_whitelist_set(p_whitelist_addr, 1);
            APP_ERROR_CHECK(err_code);
            err_code = ble_advertising_whitelist_reply(&m_advertising, &whitelist_addr, 1, NULL, 0);
            APP_ERROR_CHECK(err_code);
            break;

---

You can also use scan filtering, which filters on a higher level of abstraction than the SoftDevice, read more about the difference here.

Best regards,

Simon

[preethi16]

Hi Simon ,

Thanks for the detailed reply. I am trying on ble_peripheral where im whitelisting while using a scanner. It would be very nice of you if you can show how to whitelist in scanning in a peripheral/gatt server . I have done similar steps in the ble scanning evt handler.

Thanks,

Preethi.

[Simon]

I have not tested this, but I think I figured out how to do this with the scanner (all changes are done to ble_app_uart_c/main.c):

• In scan_init(), after memset(&init_scan, 0, sizeof(init_scan)), set init_scan.scan_param->filter_policy=BLE_GAP_SCAN_FP_WHITELIST.
• In ble_app_uart_c/main.c, under scan_evt_handler()-->case 
  NRF_BLE_SCAN_EVT_WHITELIST_REQUEST you should set the whitelist using 

  sd_ble_gap_whitelist_set()

Could you report back to me if this works or not.

Best regards,

Simon

[preethi16]

Hi Simon ,

I tired compiling with your changes and it throw me an error reporting the filter_policy is just read only. I have attached the screen post along with this message.

Thanks,

Preethi,

[Simon]

I am sorry for the long delay, I've been quite busy lately. Have you made any progress on this?

[preethi16]

Hi Simon,

Sorry for the long delay. No have not made any progress. It is still the same like i have said before . i get that error when i make those changes.

Thanks,

Preethi

[Simon]

Try to add it in the following manner instead:

static ble_gap_scan_params_t m_scan_param =                               /**< Scan parameters requested for scanning and connection. */
{
    // Other params
    .filter_policy = BLE_GAP_SCAN_FP_WHITELIST,
    // Other params
};

.
.
.
.

/**@brief Function to start scanning. */
static void scan_start(void)
{
    ret_code_t ret;

    ret = nrf_ble_scan_params_set(&m_scan, &m_scan_param);

.
.
static void scan_init(void)
{
    .
    .
    .
    init_scan.p_scan_param     = &m_scan_param;

Best regards,

Simon