BLE Sniffer stops when a connection established

RE: BLE Sniffer stops when a connection established

Simonr — Wed, 16 Dec 2020 10:57:22 GMT

That depends on how you do encryption in your application. If you use a passkey to do pairing, it should be printed to the terminal over the DKs COM port, and you can add it in the sniffer and central device to pair while the sniffer is "in".

If you don't use a passkey, I guess you're pairing using OOB. If so, you will need the OOB key. To get it, you will need to output the OOB key from the application somehow, for instance by printing it to UART using NRF_LOG_INFO(). The OOB key is requested in the BLE_GAP_EVT_AUTH_KEY_REQUEST event, and you provide the key using the sd_ble_gap_auth_key_reply() function. So I would suggest printing it right after or before the sd_ble_gap_auth_key_reply() function is called in this case. Either should be fine.

Best regards,

Simon

RE: BLE Sniffer stops when a connection established

jawadk — Wed, 16 Dec 2020 06:29:02 GMT

Hi Simonr,

[quote userid="75734" url="~/f/nordic-q-a/69402/ble-sniffer-stops-when-a-connection-established/284746#284746"]Sniffing a connection between devices that are already paired on pages 15 and 16 in the nRF sniffer user guide[/quote]

I looked into it, But the two devices is a nRF5280 !, how can I find the passkey? I didn't find it in the project

Best Regards

RE: BLE Sniffer stops when a connection established

Simonr — Tue, 15 Dec 2020 08:34:48 GMT

Great news JK! Please "verify" the answer if this ticket can be closed. That will help users with the same problem in the future find the solution quicker as well.

Best regards,

Simon

RE: BLE Sniffer stops when a connection established

jawadk — Tue, 15 Dec 2020 07:19:46 GMT

Hi,

Thank you for your help.

I erased the pairing data from the peripheral board and sniffed the pairing process at the connection and now I can sniff all the communication between the dongle and the device.

Best Regards

RE: BLE Sniffer stops when a connection established

Simonr — Mon, 14 Dec 2020 10:29:34 GMT

Can you confirm that you have chosen the correct peripheral device from the "Device list" mentioned in section 3.1 of the User guide. Does the peripheral and central not connect as intended if the sniffer is on, how do you see that the connection is established as intended when the sniffer is off?

If the devices are already paired, the issue might be that they detect the sniffer device and cancel the connection due to the sniffer device not having the correct OOB key. Please check out the Just Works -sniffing an encrypted connection and Sniffing a connection between devices that are already paired on pages 15 and 16 in the nRF sniffer user guide for more information on how to sniff a secure connection.

Best regards,

Simon