Central - use public address

[M]

Hi. I'm new to Nordic BLE devices. Using the nrf51-DK. I have a peripheral device (non-Nordic) which I want to connect to from a Nordic central (S130) using the public address. It seems that by default the address used by the central is the random one. Is this possible? How can I do this? Thanks.

[Jørgen Holmefjord]

Hi,

There should be no difference in the way you connect to a peripheral with a public or a random address.

The softdevice function sd_ble_gap_connect() takes a pointer to the address struct, ble_gap_addr_t, as agrument. This should be filled with the address and the address type. By setting the type to BLE_GAP_ADDR_TYPE_PUBLIC, you can connect to a device that has a public address.

If your central is scanning for advertising packets from the device before connecting, you can pass the address struct included in the advertising report, peer_addr, directly to the connect function.

Best regards,

Jørgen

[M]

Hi Jorden. Thank you for your reply. It seems that I didn't explain myself correctly. I need the central to identify itself using the public address. Right now when it connects to my peripheral, the peripheral shows peer (central) address type as random. Thanks

[Jørgen Holmefjord]

You can set the address using sd_ble_gap_address_set() for S130 v2.0.1 softdevice (sd_ble_gap_addr_set() for latest S132 v3.x.x softdevice for nRF52832). It takes the same address struct as described above, ble_gap_addr_t, as agrument, and you should set the addr_cycle_mode argument to BLE_GAP_ADDR_CYCLE_MODE_NONE.

[M]

Does this mean that I have to generate my own address for the central? I wanted to use the one that is already preprogrammed inside the chip by Nordic.

[Jørgen Holmefjord]

You can use the device address from FICR to fill the address struct, but this is what the softdevice does by default (if no address is found in FICR, a random address is generated). If you want a public address, you have to register this with the IEEE Registration Authority.