main.c

#include <avr/io.h>

#include <avr/interrupt.h>

#include <avr/wdt.h>

#include "usbdrv.h"

#define F_CPU 12000000L

#include <util/delay.h>

#define USB_LED_OFF 0

#define USB_LED_ON  1

// this gets called when custom control message is received

USB_PUBLIC uchar usbFunctionSetup(uchar data[8]) {

    usbRequest_t *rq = (void *)data; // cast data to correct type

    switch(rq->bRequest) { // custom command is in the bRequest field

    case USB_LED_ON:

        PORTB = ( 1 << PD5); // turn LED on

        return 0;

    case USB_LED_OFF:

        PORTB = ( 0 << PD5); // turn LED off

        return 0;

    }

    return 0; // should not get here

}

int main() {

    uchar i;

    DDRB = (1 << PD5);

    wdt_enable(WDTO_1S); // enable 1s watchdog timer

    usbInit();

    usbDeviceDisconnect(); // enforce re-enumeration

    for(i = 0; i<250; i++) { // wait 500 ms

        wdt_reset(); // keep the watchdog happy

        _delay_ms(2);

    }

    usbDeviceConnect();

    sei(); // Enable interrupts after re-enumeration

    while(1) {

        wdt_reset(); // keep the watchdog happy

        usbPoll();

    }

    return 0;

}