gbafamily:
If you are getting serial console output via the USB port you are doing it wrong. When using USB Host, serial console does not work. The board must be powered via 5V to VIN. The details are covered in the USB Host Library for SAMD README.md.
Sorry for not giving enough information.
I am not getting serial console output via USB, since there is only one USB physical interface. I am using the UART on pins 13 / 14 (Serial1) for debug, and connecting the USB devices (keyboard, mouse) through an OTG USB cable. The board is being powered with 5V at Vin pin.
I am following the USB Host Library for SAMD README.md instructions, even so I can't get a USB device recognition/enumeration to work. If you can, please, give me some further information on how can I debug this USB host function I'll really appreciate.
Thanks.