BLE - NFC

[Roei]

Hi,

I would like to ask a question regarding NFC connection.

When Im using my nrf52840 device to connect with a PC using NFC pad - the NFC triggers the nrf device to start advertising.

After that - a connection is established.

Can you please send me a link to the sequence of the connection? What exectly happens? (handshake etc)?

Thanks!

[Hung Bui]

Hi Roei, 
Please have a look at this example located in nRF5 SDK v17.0.2 : examples\ble_peripheral\experimental\ble_app_hrs_nfc_pairing

Documentation: 

https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.0.2/ble_sdk_app_hid_keyboard_pairing_nfc.html?cp=7_1_4_2_2_33

It does exactly what you want to do. 

[Roei]

Thanks! It helped me a lot.

In addition - can you please send me the sequence of the flow - including handshake, diffie hellman key exchange etc?

Thanks!

[Hung Bui]

Hi, 

What exactly you plan to do ? 

I would suggest just to leave the handshake and key exchange to the softdevice and the peer manager module. 
You can have a look at the message sequence charts here.

[Roei]

Hi,

I just want to understand the process, and I have some things that I don't understand.

When start advertising and connecting via mobile - I know that the mobile should recognize the device and send a connection request, and that the NRF device waits for connection requests while advertising.

But what happens when connection to a PC via NFC? After NRF device starts advertising - should the PC asks for a connection request?

Thanks!

[Hung Bui]

The NFC only act as a way to wake the device up and advertising. It's up to the central device (mobile phone or PC) to do what's next, for example send a connection request.