Filter already connected peripherals in adv_report

[hossein_m]

Hello Nordic,

We have an NRF52840 with SDK 16.0.0 as central in our project and multiple peripherals (which are IOS or Android phones) are supposed to connect to it. 

In adv_report function we connect to every advertising paired device . To make sure we have only one connection to each peripheral, we need a way to detect already connected devices.

I tried using pm_address_resolve to get peer_id of each peripheral and use it to detect already connected devices but using this function continuously in adv_report made NRF52 freeze without any error reports.

I thought about using peer_addrss but I think IOS and Android devices change this address although I'm not sure about this. And if this is not the case, I don't know if only saving  uint8_t addr[BLE_GAP_ADDR_LEN]; in peer_address can solve this problem.

So I would like to know which part of the advertising data can I use to detect already connected peripherals? What is the best solution for this?

Thanks

[Simonr]

Hi

The best way to connect to phones that are used as peripherals would be to use whitelisting to store the resolvable private addresses. For this, you will need the phone's IRK which will not be changed over time. To see how you can implement whitelists in your central application, please take a look at the ble_app_hrs_c example, where this feature is implemented. 

Please note that the S140 SoftDevice only supports up to 8 whitelisted devices at a time. See pm_whitelist_set and BLE_GAP_WHITELIST_ADDR_MAX_COUNT for information on that.

Best regards,

Simon

[hossein_m]

Hello Simonr

Is there anyway to perform whitelist with adv_report function instead of Scanning Module?

Thanks