/*
 * main.c
 *
 *  Created on: 12-07-2014
 *      Author: Admin
 */


/*
 * main.c
 *
 *  Created on: 12-07-2014
 *      Author: Admin
 */
#define ACK 1
#define NACK 0

#include <avr/io.h>
#include <avr/delay.h>
#include <avr/interrupt.h>
volatile uint8_t godzina, minuta, sekunda;
enum {ss, mm, hh};
/*
PC0 - godziny
PC1 - minuty
PC2 - sekundy
*/
void zapalGodziny(){
    PORTC &= ~(1<<PC0);
    PORTC |= (1<<PC1);
    PORTC |= (1<<PC2);
}
void zapalMinuty(){
    PORTC &= ~(1<<PC1);
    PORTC |= (1<<PC0);
    PORTC |= (1<<PC2);
}
void zapalSekundy(){
    PORTC &= ~(1<<PC2);
    PORTC |= (1<<PC1);
    PORTC |= (1<<PC0);
}

void TWI_start(void){
    TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTA);
    while (!(TWCR&(1<<TWINT)));
}

void TWI_stop(void){
    TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
    while (!(TWCR&(1<<TWSTO)));
}

void TWI_write (uint8_t bajt){
    TWDR = bajt;
    TWCR = (1<<TWINT)|(1<<TWEN);
    while (!(TWCR&(1<<TWINT)));
}

uint8_t TWI_read(uint8_t ack){
    TWCR = (1<<TWINT)|(ack<<TWEA)|(1<<TWEN);
    while (!(TWCR&(1<<TWINT)));
    return TWDR;
}

void TWI_write_buf ( uint8_t SLA, uint8_t adr, uint8_t len, uint8_t *buf){
    TWI_start();
    TWI_write(SLA);
    TWI_write(adr);
    while (len--) TWI_write(*buf++);
    TWI_stop();
}

uint8_t dec2bcd(uint8_t dec){
    return ((dec/10)<<4)|(dec%10);
}

void zapiszGodzineDoPCF(uint8_t godzina, uint8_t minuta, uint8_t sekunda){
    uint8_t bufor[4];
    bufor[0]=0;
    bufor[1]=dec2bcd(sekunda);
    bufor[2]=dec2bcd(minuta);
    bufor[3]=dec2bcd(godzina);
    TWI_write_buf(0xA2, 0x01, 4, bufor);
}

void TWI_read_buf(uint8_t SLA, uint8_t adr, uint8_t len, uint8_t *buf){
    TWI_start();
    TWI_write(SLA);
    TWI_write(adr);
    TWI_start();
    TWI_write(SLA+1);
    while (len--) *buf++ = TWI_read( len? ACK : NACK);
    TWI_stop();
}

uint8_t bcd2dec(uint8_t bcd){
return ((((bcd>>4) & 0x0f)*10) + (bcd)&0x0f);
}

void odczytajCzasOdPCF(){
    uint8_t bufor[3];
    TWI_read_buf(0xA2, 0x02, 3, bufor);

    sekunda = bcd2dec(bufor[ss]);
    minuta = bcd2dec(bufor[mm]);
    godzina = bcd2dec(bufor[hh]);

}

int main(void){
    sei();
    zapiszGodzineDoPCF(22,32,00);
    TCCR1A |= (1 << COM1A1) | (1 << COM1A0);
    TCCR1B |= (1 << WGM12); //  CTC
    TCCR1B |= (1 << CS12); // clk/ 256
    OCR1A = 20000; // przerwanie co mniej niz 1s
    TIMSK |= (1 << OCIE1A); // Zezwolenie na przerw. cmp match A

    //ustawienia timera do multipleksowania
    TCCR0 |= (1<<CS00) | (1<<CS01);
    TIMSK |= 1<<TOIE0;
    TCNT0 = 240;

    DDRD  = 0xff;
    DDRB |= (1<<PB2);
    DDRC |= (1<<PC0)|(1<<PC1)|(1<<PC2);
    while(1){

    }
}

ISR(TIMER1_COMPA_vect)
{
    odczytajCzasOdPCF();
        //ponizej jesli nie uzywamy RTC
        /*sekunda++;

        if (sekunda > 59){
            sekunda = 0;
            minuta++;
        }
        else
        if (minuta > 59){
            minuta = 0;
            godzina++;
        }
        else
        if (godzina >23)
            godzina = 0;
*/
}
//multiplekser
volatile char stan = 1;
ISR(TIMER0_OVF_vect){
    TCNT0 = 240;
    stan++;
    if (stan >1 && stan < 3){
        PORTD = 0xff;
        PORTD = ~godzina;
        zapalGodziny();
    }
    else
    if (stan > 4 && stan < 6){
        PORTD = 0xff;
        PORTD = ~minuta;
        zapalMinuty();
    }
    else
    if (stan > 7 && stan < 9){
        PORTD = 0xff;
        PORTD = ~sekunda;
        zapalSekundy();
    }
    else
    if (stan > 10) {
        PORTD = 0xff;
        stan = 0;
    }

}