#include <mega128.h>
#include <stdlib.h>  
#include <delay.h>
#include <stdio.h> 
#include <spi.h>



// Alphanumeric LCD Module functions
#asm
   .equ __lcd_port=0x1B ;PORTA

#endasm
#include <lcd.h>

char data_out,data,citac_1s;
char lcd_buffer[33];


void timer1 ()            
{ 
  TIFR=0x00;              //vynulovani priznaku preteceni Timeru 1
  TIMSK=0x45;             //zapne interrupt overflow na Timeru 1 --- zapne citani
  TCNT1H=0xF8;            // prednastavi horni polovinu bytu
  TCNT1L=0x30;            // prednastavi dolni polovinu bytu
  //PORTC.7=1;             
}       



// Timer 1 overflow interrupt service routine
interrupt [TIM1_OVF] void timer1_ovf_isr(void)
{

TIMSK=0x45;                                        // vypne citani Timer 1
TCNT1H=0xF8;                                       // prednastavi horni polovinu bytu
TCNT1L=0x30;                                       // prednastavi dolni polovinu bytu

}

void timer0 ()            //casovac0    
{ 
  TIFR=0x00;              //vynulovani priznaku preteceni Timeru 0
  TIMSK=0x45;             //zapne interrupt overflow na Timeru 1 --- zapne citani
  TCNT0 = 0xFF;
  PORTC.6=1;              
}       



// Timer 0 overflow interrupt service routine    
interrupt [TIM0_OVF] void timer0_ovf_isr(void)
{

TIMSK=0x45;                                        
TCNT0 = 0xFF;

if(++citac_1s == 32){  
                        PORTC.6=!PORTC.6;     // blikani led
                        citac_1s = 0;
                      
                                                                  
  }
  }

void timer2 ()            //        casovac pro detekci stisknuti tlacitka
{ 
  TIFR=0x00;              //vynulovani priznaku preteceni 
  TIMSK=0x45;             //zapne interrupt overflow na Timeru 
  TCNT2=0x00;
  PORTC.7=1;              
}       



// Timer 2 overflow interrupt service routine    
interrupt [TIM2_OVF] void timer2_ovf_isr(void)
{

  TIMSK=0x45;             
  TCNT2=0x00;
   
    }           
  
   


//--------Read single byte from SPI1 bus.
unsigned char read_spi( void )
{

  PORTB.0 = 0x01;    // nastav pin do log 1 aktivuj CE u RTC
  SPDR = 0x00;                  // initiate bus cycle
  while(!(SPSR & (1<<SPIF)));    // wait until cycle complete
  return (SPDR);              // return with byte read 
  delay_us(200); // počkej aby se dokoncil prevod 
  PORTB.0 = 0x00;    // nastav pin do log 0    deaktivuj CE u RTC

}


void write_spi(unsigned char data_out)
{
PORTB.0 = 0x01;    // nastav pin do log 1 aktivuj CE u RTC

/* Start transmission */
SPDR = data_out;
/* Wait for transmission complete */
while(!(SPSR & (1<<SPIF)));
PORTB.0 = 0x00;    // nastav pin do log 0   deaktivuj CE u RTC
delay_us(200); // počkej aby se dokoncil prevod
} 






void init_rtc(void) {
 
  write_spi(0x8F);   // zavolej adresu  control regisrtu RTC
  delay_us(200); // počkej 
  write_spi(0x00); // vloz data do control registru   povol oscilator a write protect
  delay_us(200); // počkej 
 
  write_spi(0x80); // zavolej adresu sekund
  delay_us(200); // počkej 
  write_spi(0x01); // vloz hodnotu sekund 1 
  delay_us(200); // počkej 
  
  }



void main(void)
{

PORTA=0x00;
DDRA=0x00;   // in

// Port B initialization
// Func7=In Func6=In Func5=In Func4=In Func3=In Func2=Out Func1=Out Func0=Out 
// State7=T State6=T State5=T State4=T State3=T State2=0 State1=0 State0=0 
PORTB=0x00;   
DDRB=0x07;

PORTD=0x00;   
DDRD=0x00;   //   in

PORTE=0x00;
DDRE=0x00;   // in 

PORTC=0xFF;
DDRC=0xFF;     // out

PORTG=0x00;  // 
DDRG=0x00;    // nastav jako vstupni pro krystal 32768Hz

// Timer/Counter 0 initialization
// Clock source: System Clock
// Clock value: Timer 0 Stopped
// Mode: Normal top=FFh
// OC0 output: Disconnected
ASSR=0x08;
TCCR0=0x07;
TCNT0 = 0xFF;
OCR0=0x00;

// Timer/Counter 1 initialization
// Clock source: System Clock
// Clock value: 3,906 kHz
// Mode: Normal top=FFFFh
// OC1A output: Discon.
// OC1B output: Discon.
// OC1C output: Discon.
// Noise Canceler: Off
// Input Capture on Falling Edge
// Timer 1 Overflow Interrupt: On
// Input Capture Interrupt: Off
// Compare A Match Interrupt: Off
// Compare B Match Interrupt: Off
// Compare C Match Interrupt: Off
TCCR1A=0x00;
TCCR1B=0x03;       // fosc / 64     
TCNT1H=0xF8;
TCNT1L=0x30;
ICR1H=0x00;
ICR1L=0x00;
OCR1AH=0x00;
OCR1AL=0x00;
OCR1BH=0x00;
OCR1BL=0x00;
OCR1CH=0x00;
OCR1CL=0x00;

// Timer/Counter 2 initialization
// Clock source: System Clock
// Clock value: Timer2 Stopped
// Mode: Normal top=FFh
// OC2 output: Disconnected
TCCR2=0x04;   // fosc / 256
TCNT2=0x00;
OCR2=0x00;



// Timer(s)/Counter(s) Interrupt(s) initialization
TIMSK=0x45;   // enable timer 0 1 2
ETIMSK=0x00;


// Analog Comparator initialization
// Analog Comparator: Off
// Analog Comparator Input Capture by Timer/Counter 1: Off
ACSR=0x80;
SFIOR=0x00;

// SPI initialization
// SPI Type: Master
// SPI Clock Rate: 1000,000 kHz
// SPI Clock Phase: Cycle Half
// SPI Clock Polarity: Low
// SPI Data Order: MSB First
SPCR=0x54;
SPSR=0x00;

timer1 ();
timer0 ();
timer2 ();
init_rtc();

// LCD module initialization
lcd_init(40);
lcd_gotoxy(0,0);
//lcd_putsf("hodiny");
//lcd_gotoxy(0,1);
//lcd_putsf("dnes je:");



citac_1s = 0;
data = 0x00;
data_out = 0x00;

// Global enable interrupts
#asm("sei")

 

while (1) {
  delay_ms(500); // počkej aby se zicializoval system

  write_spi(0x00);
  delay_us(200); // počkej aby se dokoncil prevod
  data = read_spi();
  delay_us(200); // počkej aby se dokoncil prevod
  
  sprintf(lcd_buffer,"%03d",data);    // uloz do buffer jako dekadicke cislo 
  lcd_puts(lcd_buffer);  // vypis na display  
  

}  
}