4.2.4 USB

The SAM D21 Xplained Pro has a micro USB receptable for use with the SAM D21 USB module. To be able to detect when a USB cable is connected, a GPIO is used to detect the VBUS voltage on the connector. The USB ID line is used to detect if a host mode cable is connected and will automatically switch on the power to the USB connector. The I/O connected to USB ID can be used to read the status of the line or manually override the voltage output. For other modes on the USB ID lines, refer to the USB organization specifications.