USB-KW41 BLE Sniffer Application Update

Document created by Mario Ignacio Castaneda Lopez Employee on Aug 17, 2018Last modified by Mario Ignacio Castaneda Lopez Employee on Aug 20, 2018
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This document describes how to update and sniff BLE wireless applications on the USB-KW41

Programming the USB-KW41 as sniffer


It was noticed that there are some issues trying to follow a BLE connection, even if the sniffer catches the connection request. These issues have been fixed in the latest binary file which can be found in the Test Tool for Connectivity Products or newest.


After the Test Tool Installation, you’ll find the sniffer binary file at the following path.

C:\NXP\Test Tool\images\KW41_802.15.4_SnifferOnUSB.bin


Programming Process.

  1. Hold the RESET button of the USB-KW41Z, then, unplug and plug the USB-KW41Z to your PC.
  2. The K22 will enter in a bootloader mode.                                                                                                       
  3. Drag and drop the "KW41_802.15.4_SnifferOnUSB.bin" included in Test tool for Connectivity Products.


Note: If the USB-KW41 is not enumerated as Mass Storage Device, please look at the next thread


General Recommendations


Software Tools 

Hardware Tools

  • 1 USB-KW41 (updated KW41_802.15.4_SnifferOnUSB.bin)


The Kinetis Protocol Analyzer provides the ability to monitor the BLE Advertisement Channels. It listens to all the activity and follows the connection when capturing a Connection Request.


BLE Peripheral device transmits packets on the 3 advertising channels one after the other, so the USB-KW41 will listen to the 3 channels one by one and could or not catch the connection request.


Common use case

The USB-KW41 will follow the BLE connection if the connection request happens on the same channel that It is listening. If is listening to a different channel when the connection request is sent, won’t be able to follow it.



A Simple recommendation is the BLE Peripheral should be set up to send the adv packets only to one channel and the sniffer just capturing on the same channel.



Use 3 USB-KW41, each of them will be dedicated to one channel and will catch the connection request.


Configure Kinetis Protocol Analyzer and Wireshark Network Analyzer


Note: For better results, address filter can be activated.

When you are capturing all the packets in the air, you will notice 3 adv packets. Each packet will show the adv channel that is getting the adv frame.




One of the three sniffers will capture the Connection Request. In this case, it happens on the channel 38.




You will be able to follow the connection, see all the data exchange.


For a better reference, you can look at the USB-KW41 Getting Started



Hope it helps