 (   USB):
1 -     3,3.  . 
2 - LEDS_LED1 - indicate that the USB interface is not ready.  .     . 
3 - LEDS_LED2 - indicate that the USB interface is ready.  .
4 -  "" 4 .    ,  . 
5 - LEDS_LED3 - indicate that the target is being powered by VBUS.  .      .