AVR 1

#define F_CPU 8000000
#include <avr/io.h>
#include <util/delay.h>
#include <stdlib.h>

void init(void){
DDRB=0xff;
PORTB=0x00;
}
 double times;
int main(void)
{
init();
while(1){
     times=1000+rand()%50;
        PORTB=0xff;
       _delay_loop_1(times);
        PORTB=0x00;
        times=1000+rand()%50;
        _delay_loop_1(times);
}}