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.

[Stroker347]

Amanda,

One more question:

Do you know if the nRF Sniffer V3 firmware will work with the Adafruit Bluefruit LE Friend Sniffer V2, which is based on the nRF51288 and comes preloaded with the nRF Sniffer V2 firmware?

Earlier versions of the Bluefruit LE Friend Sniffers came with a special version of the nRF V1 firmware that did not use the 32kHz clock, which the hardware did not have. I don't know if this is true for the V2 hardware.

If the V3 firmware will work I think I can reflash the hardware. I would rather use the V3 firmware since the V3 software interface to Wireshark works with Python 3.8 and its supporting modules which I already have installed. I would have to install Python 2.6 and its supporting modules in order to use the V2 firmware that comes preloaded.

Randy

[Amanda Hsieh]

Hi Randy,

Stroker347 said:

Do you know if the nRF Sniffer V3 firmware will work with the Adafruit Bluefruit LE Friend Sniffer V2, which is based on the nRF51288 and comes preloaded with the nRF Sniffer V2 firmware?

 Sorry, I don't know that. Not sure whether there is a version compatible issue or not.

-Amanda H.