Hi Albert,
The LED behavior depends on the application that is flashed. Considering Thread Applications, blinking both LEDs means that the device is in Factory default state (not joined to a specific network).
Regarding the methods for updating via the USB, this could be done if the board is flashed with a bootloader application. In our sdk an example of bootloader(in this case for FRDM board, but could also be updated for USB board) is at the following location:
....\MKW2xD_ConnSw_1.0.2\boards\frdmkw24\wireless_examples\framework\bootloader_fsci
C or Python Scripts for using with fsci bootloader are:
...\MKW2xD_ConnSw_1.0.2\tools\wireless\host_sdk\hsdk\demo\FsciBootloader.c
or
...\MKW2xD_ConnSw_1.0.2\tools\wireless\host_sdk\hsdk-python\src\com\nxp\wireless_connectivity\test\bootloader\fsci_bootloader.py
and documentation: ...\MKW2xD_ConnSw_1.0.2\docs\wireless\Thread -> Kinetis Thread Stack and FSCI Bootloader Quick Start Guide.pdf
Let us know if you need more details.
Regards,
Ovidiu
