Embedded Systems (Betty)

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

uint16_t i = 0,j = 0, n = 0;

ISR(INT0_vect){
        PORTB = 0x00;
    for(j = 0; j < 2; j++){
        _delay_ms(500);
        PORTB ^=  0xff;//(1<<PORTB1) | (1<<PORTB2) |(1<<PORTB3) ;
        _delay_ms(500);
    }
}

int main(void)
{
    DDRB = 0xFF;
    EIMSK = 0x01;
    EICRA = 0x02;
    sei();
    ADCSRA = (1 << ADEN) | (1 << ADIE) | (0 << ADPS0) | (1 << ADPS1) | (1 << ADPS2) | (1 << ADSC);
    ADMUX = (1 << ADLAR) ;
    while(1)
    {
        TCCR1A = 0x00;
        TCCR1B = 0x00;
        TCCR2A = 0x00;
        TCCR2B = 0x00;


        if(n <= 127){
            for(i = 0; i<2; i++){
                PORTB = 1<<PORTB1;
                _delay_ms(1000);
                PORTB = 1<<PORTB2;
                _delay_ms(1000);
                PORTB = 1<<PORTB3;
                _delay_ms(1000);
            }
        }
        else{
            for(i = 0; i<2; i++){
                PORTB = 1<<PORTB3;
                _delay_ms(1000);
                PORTB = 1<<PORTB2;
                _delay_ms(1000);
                PORTB = 1<<PORTB1;
                _delay_ms(1000);
            }
        }
        TCCR1A = (1<<COM1A1) | (1<<COM1B1 ) | (1<<WGM10);
        TCCR1B = (1<<WGM12) | (1 << CS10) ;
        TCCR2A = (1 << COM2A1) | (1 << WGM21) | (1 << WGM20);
        TCCR2B = (1 << CS20);
        for(i=0;i<255;i++){
            OCR1A = i;
            OCR1B = i;
            OCR2A = i;
            _delay_ms(20);
        }
    }
}

ISR(ADC_vect){
    n = ADCH;
    ADCSRA |= (1 << ADSC);
}