Arduino timer

gistfile1.txt

#include <avr/interrupt.h>



//COMMON CATHODE
// define the way to activate 7 Segment leds
byte segment7code[] = {
  				  		0b00111111, // 0
						0b00000110, // 1
						0b01011011, // 2
						0b01001111, // 3
						0b01100110, // 4
						0b01101101, // 5
						0b01111101, // 6
						0b00000111, // 7
						0b01111111, // 8
						0b01101111  // 9
				       };

// define the 7 Segment display to be activated to update hours, minutes, seconds
byte portB_To_segment7[] = {			//seven-segment activation codes
  							0b111110,	//from seconds to hours
  							0b111101,
  							0b111011,
  							0b110111,
  							0b101111,
  							0b011111
						   };

// initial time
int timeArray[] = {
  					0,	//seconds unit
  					0,	//seconds decimal
  					0,  //minutes unit
  					0,  //minutes decimal
  					0,  //hours   unit
  					0   //hours   decimal
				   };

int counter = 0;	//timer counter
int dataPin = 5, clockPin = 6, latchPin = 7; //74HC595 wiring


// send data to 74HC595
void shiftOutput(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val)
{
     uint8_t i;

     for (i = 0; i < 8; i++)  {
           if (bitOrder == LSBFIRST)
                 digitalWrite(dataPin, !!(val & (1 << i)));
           else      
                 digitalWrite(dataPin, !!(val & (1 << (7 - i))));
                 
           digitalWrite(clockPin, HIGH);
           digitalWrite(clockPin, LOW);            
     }
}

ISR(TIMER1_COMPA_vect)
{
  /*
  	This method is executed when timer1 match the value stored in OCR0A
  */
  
  	SREG &= (0 << SREG_I);
  	
  	counter++;
  	if(counter>=62)
    {	
      	counter = 0;
  		timeArray[0]++; //adds 1 second
    }
    
  	if (timeArray[0] > 9)	//checks second units
    {
      	timeArray[0] = 0;
      	timeArray[1]++;
      	
      	if (timeArray[1] > 5) //checks second decimals
        {	
          	timeArray[1] = 0;
          	timeArray[2]++;
          	if (timeArray[2] > 9) //checks minute units
            {
            	timeArray[2] = 0;
              	timeArray[3]++;
              	if (timeArray[3] > 5) //checks minute decimals
                {
                	timeArray[3] = 0;
                  	timeArray[4]++;
                	if (timeArray[4] > 9) //checks hour units
                	{
                      	timeArray[4] = 0;
                		timeArray[5]++;
                	}
                  	if(timeArray[5] ==  2 && timeArray[4] == 4) //checks for new day
                    {
                    	timeArray[4] = 0;
                      	timeArray[5] = 0;
                    }
                  
				}
			}
        }
	}  	  
  
	SREG |= (1 << SREG_I);
}

void setup()
{
  	DDRB = 0xFF; // 0b11111111 
  	DDRD = 0xFF; // 0b11111111 
	PORTB = 0xFF; // 0b11111111 
  	PORTD = 0x00;// 0b00000000
  
    //16 bit timer configuration attempt
   	SREG |= (1 << SREG_I); // enable global interrupt
  	TCCR1A = (1 << WGM11) | (0 << WGM10); // PWM, phase correct, 9-bit - incrementeaza si apoi decrementeaza la 0
  	OCR1A  = 0xFA00; // 64000 out of 65536
    TIMSK1 |= (1 << OCIE1A); // enable timer 1
  	sei(); // enable global interrupt, wait, why?
  	TCCR1B = (1 << CS12 ) | (0 << CS11 ) | (0 << CS10 ) ; // prescale with 256
	
  	
}

void loop()
{ 
  	
  	for (int i=0; i<=5; i++)
    {
     	PORTD = (0 << latchPin);
      	shiftOutput(dataPin, clockPin, MSBFIRST, segment7code[timeArray[i]]);
      	PORTB = portB_To_segment7[i]; // define which display to update
      	PORTD = (1 << latchPin); // "submit" the changes to 74HC595
      	delay(4);
	}
}