Can I use the BL654 USB Dongle as USB HCI Bluetooth device?

There exist two variants of the BL654 dongle:

• 451-00003 is the SmartBASIC driven version which uses an FTDI USB UART converter for USB connection.
• 451-00004 is the Nordic version which leverages the nRF52840 native USB device interface.

Whereas the SmartBASIC version cannot be used anything different than a virtual serial port device from a USB perspective, the Nordic version could be programmed for different USB device classes.
The Zephyr project provides various sample application projects including a Bluetooth usb_hci project. Since the BL654 USB Nordic dongle is a supported board in Zephyr it is possible to compile and load the usb_hci project into the dongle. After doing so, the dongle will operate as a Bluetooth HCI device and enumerate on USB accordlingly. Please follow the general build instructions for Zephyr and the programming/flashing instructions for the BL654 USB dongle.