nrf51 DK BLU sniffer has no devices listed in Device drop-down

[eric7L]

I have a smartwatch, smartphone, and tablet.

I went to some place without any other bluetooth devices, my devices are able to scan and pair with each other. But nRF-51 not able to see any of those devices in the Wireshark Device drop-down. It is empty. And then I went back to the lab and I'm able to see all other Bluetooth devices with nRF-51. 

I'm using the OS X runs the nRF Sniffer software v2. Wireshark V2.4.2. SEGGER J-Link v6.16c. 

I tried all the common sniffing actions in "nRF_Sniffer_User_Guide_v2.1.pdf", I just cannot find my devices in Devices drop-down list. 

I have tried those actions:

  1. Before the devices pair, I turn on the Bluetooth scanning mode in each device, my Wireshark Devices drop-down list is empty. 

  2. During the devices paring, my Wireshark Devices drop-down list still empty.

  3. After the devices paired, my Wireshark Devices drop-down list still empty.

This screenshot shows that I am able to see other devices besides my watch, phone, and tablet.  

I saw a thread from Stack overflow mentions about the Bluetooth LE peripheral mode. I'm not sure if this causes my problem here. 

[Hung Bui]

Hi Eric, 

 

What do you expect to see of those device (smartwatch, smartphone, and tablet.) in the sniffer ? 

Are you sure they actually do BLE advertising ? Smart Phone and Tablet usually don't do any BLE advertising if it's not from the app. 

The smart watch may do BLE advertising if it's not in a connection and if it actually do BLE. Many smartwatches actually use classic Bluetooth instead. 

The nRFSnifer can only follow a connection if it can track the connection establishing process. Basically you need to select the device in the drop down list when it's advertising, and then after that you start the connection. 

[eric7L]

The watch is using Bluetooth 4.1 LE. does nRFSnifer support it?

[Hung Bui]

Yes, if it actually use Bluetooth Low Energy.

What I would suggest you to do is to disconnect the watch from the phone (turn off Bluetooth on the phone), unpair it if possible. Start your sniffer, check if your watch appear in the list. If it does, select it in the drop down menu. 

Then you turn Bluetooth on your phone and start pairing with the watch. This time your sniffer should be able to follow the connection. 

[eric7L]

Thank you Hung.

I still cannot see the watch in the list. Its that mean the watch is not using BLE?  even though the watch's specification saying Bluetooth 4.1 LE. 

[Hung Bui]

I'm not sure, you can check it by using nRFConnect app on the phone to scan for the watch (before you pair /connect it with your phone or with any other device). Then you can use nRFConnect to connect to the watch and make sure you see the Attribute table of the watch. 

[eric7L]

Thank you, Hung.

I just bought a new smartwatch, and I am able to see this new watch on the list before it pair. However, I selected it in the drop-down menu, then I turn Bluetooth on my phone and start pairing with the new watch. the Wireshark doesn't appear any "Pairing process" as the youtube video showing here Nordic Semiconductor - nRF Sniffer at 5:33. Also, It doesn't have any new 'info' between two devices, like in you guys video has encrypted "info: RCVD Connection....", my still has "adv_IND[Malformed Packet]" or " ADV_IND" from Slave to Master. It that possible because the MAC been changing for the specific packets and they are using the actual MAC address for "ADV_IND".  In Bluetooth Technology Protecting Your Privacy saying that the real MAC address remains hidden away.  is nRF Sniffer able keep tracking the devices after they pairing and if the real MAC address remains hidden? 

[Hung Bui]

Hi Eric, 

 

The main purpose of the sniffer we made was not for sniffing 3rd party devices. It's more for developing and debugging Nordic chip's application. 

The privacy the document talking about is about the ability to change address when advertising, however the address in the connection request and address when advertising should be the same to be able to establish a connection. The device can change the address when advertising but not too often, usually we see address changes every 15 minutes. (Bonded device can recognize each other by resolve the random addresses using IRK) 

There is a chance that the sequence of advertising channel of the smart watch is not the same as the default sequence we have of 37 38 39. You need to check that. 

 

I strongly suggest you to get familiar with Bluetooth technology by testing with our chip and our development tools first, before you get started with tracking a connection of a third party end device that you don't have control over the source code or know what it would do.