I don't get the example from Atmel:
(http://www.atmel.com/Images/AVR328.zip)

isn't led_state and led_number the same?
I'm missing sth but what?

//* Read report from HID Generic Demo
      U8 led_state;
      U8 led_number;
      led_state      = Usb_read_byte()&0x0F; // RepportOUT[0] is LEDS value
      led_number     = Usb_read_byte()&0x0F;
      switch (led_number)
      {
         case 1:
            if(led_state)
            {  Led0_on();   }
            else {Led0_off();}
            break;
         case 2:
            if(led_state)
            {  Led1_on();   }
            else {Led1_off();}
            break;
         case 3:
            if(led_state)
            {  Led2_on();   }
            else {Led2_off();}
            break;
         case 4:
            if(led_state)
            {  Led3_on();   }
            else {Led3_off();}
            break;
      }

 

led_state == On or Off
led_number == the selected led.

E

 

led_state == On or Off
led_number == the selected led.

E

I understood that

What I don't get is why do they get different value if both are U8 and get the value by:
=Usb_read_byte()&0x0F;

 

What I don't get is why do they get different value if both are U8 and get the value by:
=Usb_read_byte()&0x0F;

Because each call of the function reads the next byte, and one byte can be different from another.