#define F_CPU 128000UL

#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>


#define MOSIPIN PB5
#define REGPIN PB4
#define CLK_PIN PB7

volatile int sekunde = 0;
volatile int intteruptCount = 0;
volatile int i=0;

void startUP() {
    cli();  //Disable Interrupts

    TIMSK   |= (1<<OCIE0A) | (1<<TOIE0);        //Enable OCIE0A: Timer/Counter0 Output Compare Match A Interrupt Enable

    DDRB    = 0xFF;
    PORTB   = 0x00;

    DDRD    = 0xFF;
    PORTD   = 0x00;

    DDRB |= (1<<PB5);
    DDRB &= ~(1<<PB6);



    CLKPR = 0x80;   //Ukljuci prescale originalnog takta


    TCCR0A  |= (1 << WGM01);                // Configure Timer 0 for CTC mode
    TCCR0B  |= (1 << CS02) | (1 << CS00);   //Prescaling the timer (1024)

    OCR0A   = 0xF9;                         // Set CTC compare value to 1Hz AVR clock, with pre-scaler of 1024
    TCNT0   = 0x06;                         //Podesi brojac odakle da pocne da broji



    sei();  //Enable Interrupts
}


unsigned char SPI_SR(unsigned char data)
{
    USIDR = data;
    USISR = (1<<USIOIF); // clear IRQ
    while ((USISR & (1<<USIOIF)) == 0)// send 8 bits
    {
        // Positive edge SCK clock strobe
        USICR = (1<<USIWM0)|(1<<USICS1)|(1<<USICLK)|(1<<USITC);
    }
    return USIDR;
}

void RegisterCLK() {

    PORTB &= ~(1<<REGPIN);
    _delay_ms(10);
    PORTB |= (1<<REGPIN);
    _delay_ms(10);
    PORTB &= ~(1<<REGPIN);
    _delay_ms(10);
}


//Timer0 Interrupt funkcija
ISR(TIMER0_COMPA_vect)
{
    //PORTD ^= 0xFF;
    //PORTB ^= 0xFF;
}

int main(void)
{

    startUP();
    RegisterCLK();


    while(1)
    {
        PORTB &= ~(1<<MOSIPIN);
        _delay_ms(10);
        for(i=0; i<8; i++) {
            PORTB &= ~(1<<CLK_PIN);
            _delay_ms(10);
            PORTB |= (1<<CLK_PIN);
            _delay_ms(10);
        }
        RegisterCLK();

        _delay_ms(1000);

        PORTB |= (1<<MOSIPIN);
        _delay_ms(10);
        for(i=0; i<8; i++) {
            PORTB &= ~(1<<CLK_PIN);
            _delay_ms(10);
            PORTB |= (1<<CLK_PIN);
            _delay_ms(10);
        }
        RegisterCLK();
        _delay_ms(1000);
    }
}