Human interface on SAM3X-EK:
- SAM3X USART used UART on J11 connector
- Led 3 (D5, red) is on when USB OTG cable is plugged in and Vbus is present
- Led 1 (D4, green) is continuously on when a device is connected
- Led 0 (D2, blue) blinks when USB host has checked and enabled CDC interface
- 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 2 (D3, amber) is on during data transfer between CDC and UART
1.8.5