// ----- Functions -----
uint8_t usb_configured(); // is the USB port configured
+uint8_t usb_init(); // Returns 1 on success, 0 if no cable is attached
-void usb_init();
void usb_isr();
void usb_tx( uint32_t endpoint, usb_packet_t *packet );
void usb_tx_isr( uint32_t endpoint, usb_packet_t *packet );