bluefruit le friend sniffer firmware version Moderators: adafruit_support_bill, adafruit

[Stroker347]

Is the latest Nordic nRf sniffer V3.1 firmware compatible with the Bluefruit LE Friend sniffer?

[Stroker347]

Typical of forums we have to answer our own questions. After adding an SWD connector to my Bluefruit LE Friend Sniffer V2 Firmware device, I was able to flash the latest Nordic Sniffer V3 firmware "sniffer_pca10028_129d2b3.hex" to the device and it seems to work well with the minor exception that the blue led no longer lights. Even after re-flashing the V2 beta firmware "sniffer_pca10028_51296aa.hex" file, which is supposed to be the pre-loaded version, the blue led still didn't work. To perform the flashing I used the Nordic "nRF Connect for Desktop", Programmer module, and my Segger JLink EDU mini programmer hardware. Upon opening the Programmer module the JLink EDU mini showed up as a selectable device and the Add HEX File option allowed browsing to the location of the new firmware. Then it was as easy as selecting "Erase & write".
With the V3 firmware installed the device appears to work seamlessly with Wireshark 3.2.4 and Python 3.8. Previously with V2 firmware I experienced some Wireshark crashes when starting, stopping and refreshing the sniffer capture.
Eventually I'll try flashing some non-sniffer firmware to the device to see if the blue led is dead (I'm sure, however, that it was lit just prior to flashing so I don't think it was damaged due to soldering).

[Stroker347]

I did upload firmware that is native to the non-sniffer Bluefruit LE Friend and it appears to do everything its supposed to and all the leds light up as they should. I was also able to perform an update over-the-air using the Bluefruit Connect app running on an Android phone. So I conclude that the device is working properly and I can now switch between the sniffer firmware and the non-sniffer firmware with just a few clicks of a mouse using the Nordic nRF Connect for Desktop, Programming module.

[Stroker347]

For anyone adventurous enough to have performed an installation of the Nordic V3.1 sniffer firmware on their Bluefruit LE Friend device, I figured out what was needed to get the Blue LED functioning again. The sniffer firmware file "sniffer_pca10028_1292b3.hex" was written for the Nordic nRF51 DK board, which has four LEDs that are connected to the nRF51822 GPIO pins 21 thru 24. whereas the LE Friend has a Red and Blue LED connected to the nRF51822 GPIO pins 18 and 19 respectively. The sniffer firmware toggles LED1 to show BLE radio activity. To get the LE Friend Blue LED to flash, the pin selection number must be switched from 21 to 19 in the firmware. The selected pins for the LEDs are hardcoded into firmware starting at hex file address 0x3465 for pin 21 (0x15). Replacing 0x15 with 0x13 will change the selection for LED1 to pin 19. With this simple change the LE Friend Blue LED will flash in response to the radio receiving packets from valid BLE addresses. When the sniffer capture address is set, the LED only flashes when receiving packets for that address. I suspect that a similar change was made by Adafruit technicians to get the LED working with the as supplied V2 sniffer firmware, but they may not be legally allowed to make their modified file available for customer installation.

[Stroker347]

In my last post, I hadn't realized that the sniffer hex file is in "Intel Hex" format, which is an ASCII text file that represents binary hex data as ASCII characters. The binary image location 0x3465, at which the LED pin number is coded, can be edited directly in device memory (which is what I did) by connecting the device to a JLink programmer and using the Segger Ozone debugger. Alternatively, the program HxD Hex Editor allows importing files in "Intel Hex" format and will then display the binary image in the main window. Any changes that are made to the image have to be saved using the export "16 bit Intel Hex" option rather than the file menu "save" option.