1  #include <avr/io.h>
2  #include <util/delay.h>
3 
4  int main(void)
5  {
6    DDRB |= (1 << PINB0);
7    PORTB &= ~(1 << PINB0);
8	
9    while(1)
10   {
11     _delay_ms(1000);
12     PORTB ^= (1 << PINB0);	
13   }
14 }