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.
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.