#include <stdio.h>
#include <avr/io.h>
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
    #define  F_CPU 16000000UL
#include <util/delay.h>

volatile unsigned int ADC_w = 0;

int
segment_decoder(int num, int point)
{
int result = 0x3F;
    switch(num)
    {
        case 0: result = 0x3F;
        break;
        case 1: result = 0x06;
        break;
        case 2: result = 0x5B;
        break;
        case 3: result = 0x4F;
        break;
        case 4: result = 0x66;
        break;
        case 5: result = 0x6D;
        break;
        case 6: result = 0x7D;
        break;
        case 7: result = 0x07;
        break;
        case 8: result = 0x7F;
        break;
        case 9: result = 0x6F;
        break;
        default: result = 0x3F;
        break;
    }

if(point!=0)
    {
    result = (result | 0x80);
    }

  return result;
}

ISR(ADC_vect)
{
    ADC_w = ADCW;//ADCL;
}


int main(void)
{
_delay_ms(2);

DDRA = 0x00;
DDRB = 0xFF;
DDRC = 0xFF;
DDRD = 0xFF;

PORTA= 0xFF;
PORTB= 0x00;
PORTC= 0x00;
PORTD= 0x00;


SREG    |= _BV(7);

   ADCSRA |= (1<<ADPS0);
   ADCSRA |= (1<<ADPS1);
   ADCSRA |= (1<<ADPS2);
    
ADMUX  = 0x40;
    
   ADCSRA |= (1 << ADATE);
   ADCSRA |= (1<<ADIE);
   ADCSRA |= (1<<ADEN);

sei();
   while(1)
    {
    ADCSRA |= (1<<ADSC);
    while(ADCSRA & 0x40)
    {
            PORTB = segment_decoder( (ADC_w/1000)%10, 0);
        PORTD = 2;
    _delay_us(10);
        PORTD = 0;
            PORTB = segment_decoder( (ADC_w/100)%10, 0);
        PORTD = 4;
    _delay_us(10);
        PORTD = 0;
            PORTB = segment_decoder( (ADC_w/10)%10, 1);
        PORTD = 8;
    _delay_us(10);
        PORTD = 0;
            PORTB = segment_decoder( ADC_w%10, 0);
        PORTD = 16;
    _delay_us(10);
    }
    };

return 0;
}

int main(void)
{
_delay_ms(2);

[b]DDRA = 0x00;[/b]
DDRB = 0xFF;
DDRC = 0xFF;
DDRD = 0xFF;

[b]PORTA= 0xFF;[/b]
PORTB= 0x00;
PORTC= 0x00;
PORTD= 0x00;