Human interface on SAM L21 Xplained Pro:
- Led 0 is on when it's host and there is no device connected
- Led 0 blinks when a device is enumerated and USB in idle mode
- The blink is slow (1s) with low speed device
- The blink is normal (0.5s) with full speed device
- The blink is fast (0.25s) with high speed device
- Led 0 is on during data transfer between CDC and UART
- Button SW0 allows to enter the device which support the LPM in LPM suspend mode with remote wakeup feature authorized.
- Only SW0 button can be used to wakeup USB device in LPM suspend mode