Wireshark cannot find interface to nRF51 dongle

RE: Wireshark cannot find interface to nRF51 dongle

edw — Fri, 10 Jul 2020 18:32:27 GMT

We can close this case now.

I decided to erase and re-flash the dongle.

This allowed everything to work.

thanks for your help !

RE: Wireshark cannot find interface to nRF51 dongle

edw — Fri, 10 Jul 2020 17:39:09 GMT

I have looked into nrf_sniffer_ble.py and determined that UART.find_sniffer returns an empty list.
reader.decodeFromSLIP(0.3, complete_timeout=0.3) always times out.
I uncommented these lines in UART.readByte
logging.info('rbtype: {}'.format(r.__class__))
logging.info('r: {}'.format(r))
and set the logger level to logging.INFO
to see if it was seeing any values on the interface.

There is something there, but it never finds a SLIP_START.
Here is the output from such a trial.
I removed all the lines "rbtype: <class 'int'>" to shorten this list.
Does this provide any useful information ?

% ./nrf_sniffer_ble.sh --extcap-interfaces
Started PID 836
Namespace(baudrate=None, capture=False, device='', extcap_capture_filter=None, extcap_config=False, extcap_control_in=None, extcap_control_out=None, extcap_dlts=False, extcap_interface=None, extcap_interfaces=True, fifo=None, only_advertising=False)
extcap {version=3.0.0}{display=nRF Sniffer for Bluetooth LE}{help=www.nordicsemi.com/.../nRF-Sniffer-for-Bluetooth-LE}
Opening serial port /dev/cu.Bluetooth-Incoming-Port
rbtype: <class 'NoneType'>
r: None
closing UART
Opening serial port /dev/cu.Bluetooth-Incoming-Port
rbtype: <class 'NoneType'>
r: None
closing UART
Opening serial port /dev/cu.usbmodem0006801572801
r: 192
r: 0
r: 47
r: 0
r: 209
r: 1
r: 126
r: 192
r: 192
r: 0
r: 47
r: 0
r: 209
r: 1
r: 126
r: 192
r: 192
closing UART
Opening serial port /dev/cu.usbmodem0006801572801
r: 252
r: 248
r: 249
r: 248
r: 254
r: 248
r: 255
r: 252
r: 252
closing UART
control {number=0}{type=selector}{display=Device}{tooltip=Device list}
control {number=1}{type=string}{display=Passkey / OOB key}{tooltip=6 digit temporary key or 16 byte Out-of-band (OOB) key in hexadecimal starting with '0x', big endian format. If the entered key is shorter than 16 bytes, it will be zero-padded in front'}{validation=\b^(([0-9]{6})|(0x[0-9a-fA-F]{1,32}))$\b}
control {number=2}{type=string}{display=Adv Hop}{default=37,38,39}{tooltip=Advertising channel hop sequence. Change the order in which the siffer switches advertising channels. Valid channels are 37, 38 and 39 separated by comma.}{validation=^\s*((37|38|39)\s*,\s*){0,2}(37|38|39){1}\s*$}{required=true}
control {number=3}{type=button}{role=help}{display=Help}{tooltip=Access user guide (launches browser)}
control {number=4}{type=button}{role=restore}{display=Defaults}{tooltip=Resets the user interface and clears the log file}
control {number=5}{type=button}{role=logger}{display=Log}{tooltip=Log per interface}
value {control=0}{value= }{display=All advertising devices}{default=true}
Exiting PID 836

RE: Wireshark cannot find interface to nRF51 dongle

edw — Fri, 10 Jul 2020 17:16:01 GMT

I'm sorry I was not clear.

The nrf_sniffer_ble still does NOT work for me.

I mentioned that the Bluetooth Low Energy app does work for me, because I thought that might provide

some confirmation that the appropriate hex file had been flashed to the dongle.

RE: Wireshark cannot find interface to nRF51 dongle

Edvin — Fri, 10 Jul 2020 16:50:31 GMT

It is not the same application. The Bluetooth Low Energy app is an application that takes serial commands from the computer, and scans for and connects to a device, pretty much like the examples in the SDK. Then it reports events and changes in characteristics back to the computer.

The Sniffer application is not using the softdevice, like the SDK does. It is a custom FW that will scan for advertisement packets on channel 37. When it receives this, it switches to 38 and tries to catch that same packet on that channel, and then on channel 39. It is possible to tell the sniffer FW (via serial from computer) to follow a specific device. If so, it will filter out anything that is not related to that device. It will also follow that device into a connection. Just picking up the connection request, and the channel map, and continue to sniff the packets from both the peripheral an central in that connection. This is not at all possible using the Softdevice that is used in nRF Connect -> Bluetooth Low energy. The sniffer is not capable of connecting to a device on it's own. Only follow a device into a connection. The sniffer will never transmit a packet. Only listen, and dump the relevant data over serial.

So does this mean that the sniffer is working, or did I misunderstand?

Best regards,

Edvin

RE: Wireshark cannot find interface to nRF51 dongle

edw — Fri, 10 Jul 2020 16:20:09 GMT

Yes. I used sniffer_pca10031_129d2b3.hex after checking the sticker on the dongle.

How does Bluetooth Low Energy app interact with the dongle? As I mentioned, I am able to use it successfully with the dongle.

I expected that it used the same code on the dongle as what is used for the Wireshark interface. Is this true?

RE: Wireshark cannot find interface to nRF51 dongle

Edvin — Fri, 10 Jul 2020 14:47:08 GMT

Hello,

Did you flash the dongle with the appropriate FW? The .hex file you can use should be found in the nrf_sniffer_for_bluetooth_le_3.0.0_129d2b3\hex.

Depending on what version of the dongle you have, it would be either the sniffer_pca10031_129d2b3.hex or the sniffer_pca10000_129d2b3.hex. There should be a white sticker saying either pca10031 or pca10000 on the dongle.

BR,

Edvin