Thanks DavidAlfa !
It works in UART mode (And Termite communicates with it without any problem), this will already be of great help for me.
But in I²C/SPI mode, in the list of peripherals, it appears now as "Unknown device" (with the official driver you mentionned)
I tried the "Uninstalling/Reboot/Reinstall/Reboot/Plug the device in" sequence, but still not OK in I²C/SPI mode.
Any idea ?
Is there a specific driver for that mode ?