ble-sniffer_win_1.2_nRF51822

[Stroker347]

The ble-sniffer_win_1.2_user_guide, Figure 4. Wireshark Interface, Packet Bytes window shows a 00 byte at location 0010, which corresponds to the "preamble" of the "Air Interface Packet" defined in Bluetooth Specification Version 4.2[Vol 6, Part B], Section 2. As defined in Section 2.1.1 Preamble, this byte should be either AA or 55 for an Advertising channel packet such as a CONNECT_REQ, which is what is being displayed in Figure 4 of the user guide. I have seen this same 00 byte for the preambles shown in Wireshark output figures for the Adafruit Bluefruit LE Friend nRF51822 Sniffer (which is pre-loaded with the Nordic ble_sniffer firmware) that I have ordered. I am wondering if there is a bug in the sniffer firmware or some limitation that prevents it from capturing or displaying this byte correctly, otherwise how could it be 00 since this doesn't conform to the Bluetooth Specification?

[Amanda Hsieh]

Hi, 

In the Bluetooth Specification Version 4.2[Vol 6, Part B], Section 2. As defined in Section 2.1.1 Preamble:

If the LSB of the Access Address is 1, the preamble shall be 01010101b, otherwise the preamble shall be 10101010b.

The preamble could get from the LSB of the Access Address. We don't put it into the BLE packet to increase the speed. 

-Amanda H.

[Stroker347]

Amanda,

Thanks for your prompt reply, Nordic's tech support is awesome!

I asked about the preamble because I think if its not being sent correctly it could be the cause of the connection problem I am experiencing that appears to be a timing/synchronization issue between my advertiser and scanner. I am disappointed to hear that I won't be able to expose it with the nRF Sniffer. I haven't received my sniffer hardware yet (an Adafruit Bluefruit LE Friend Sniffer V2 nRF51822, preloaded with Nordic's nRF Sniffer V2 firmware), but hopefully when I do I'll find the source of my problem is something other than an incorrect preamble.

Questions:

1) Will the Nordic nRF Sniffer V3.1 software (interface to Wireshark) work with the V2.0.0 firmware?

2) I've recently been thinking that I should order a Nordic nRF52 DK for my sniffer hardware. Can that board be programmed (when not using it as a sniffer) with Arduino?

Randy

[Amanda Hsieh]

Hi Randy,

Stroker347 said:

1) Will the Nordic nRF Sniffer V3.1 software (interface to Wireshark) work with the V2.0.0 firmware?

No. You have to use the firmware provided with the same nRF Sniffer software package. 

 

Stroker347 said:

2) I've recently been thinking that I should order a Nordic nRF52 DK for my sniffer hardware. Can that board be programmed (when not using it as a sniffer) with Arduino?

 Please see Bjorn's answer in this post. 

-Amanda H.