#include <avr/io.h>


void display_on(int);
void decode(int, int);
void delay_1ms();
char get_button();

// Button
int pressed = 1;
 
 int main(void)
 {
   DDRB = 0xFF; // Cathode (4)
   DDRD = 0xFF; // Anode
   DDRC = 0b11110000; // 4 Buttons
   // Numbers
   // Indicate the mode of the clock
   // 1: Increase
   // 2: Decrease
   int mode = 1;
   
   // Numbers
   int DIP[4] = {0,0,0,0};
   int DOT[4] = {0,0,1,0}; 
	  
   int display = 0;
   int value_display = 0;
   int count = 0;
   int increment = 1;
   
   // Set blink
   int stack_blink = 0;
   int set = 0;
   int BLINK_CONSTANT = 100; // 0.5s encendido 0.5s apagado
   int blink_counter = BLINK_CONSTANT;
   // Blink stop
   int stop_blink = 0;
   int BLINK_STOP = 2*5*BLINK_CONSTANT*4;
   int stop_counter = BLINK_STOP; // 5s
   int display_out = 1;	// Out on
   
   // Digit set
   int digit = 0;
   
   // Stop: 0
   // Start: 1
   int status = 0;
   char button = ' ';
   while(1)
   {
     // Get button
	   button = get_button();
	   // Stop/Start
	   if (button=='S' && pressed==1){
		   stack_blink = 0;
		   if (status==1 && set==0){
			   status = 0;
		   }
		   // Start
		   else{
			   status = 1;
			   set = 0;
		   }
		   pressed = 0;
	   }
	   // Reset
	   else if (button=='R' && pressed==1){
      mode = 1;
			stack_blink = 0;
			set = 0;
			value_display = 0;
			status = 0;
			pressed = 0;
		}
		// Set
		else if (button=='T' && pressed==1){
			mode = 2;
			status = 0;
			blink_counter = BLINK_CONSTANT;
			if (set==0){
				set = 1;
				stack_blink = 0;
			}
			else{
				stack_blink += 1;	
				if (stack_blink==4){
					stack_blink = 0;
				}			
			}
			pressed = 0;
		}
		// Increase
		else if (button=='I' && pressed==1 && set==1){
			digit = (int)(value_display/pow(10, stack_blink))%10;
			
			if (digit==9){
				value_display -= 9*pow(10, stack_blink);
			}
			else{
				value_display += pow(10, stack_blink);	
			}	
			
			pressed = 0;
		}
	   	// Counter 0-999.9
	   // 1ms
	   if (status==1){
		   if (count==90){
			   value_display += increment;
			   count = 0;
		   }		   
		   //Add 1 to counter
		   count += 1;
	   }
	   if (mode==1){
		   increment = 1;
		   if (value_display>=10000){
			   value_display = 0;
			   // Stop cronometer
			   status = 0;
		   }
		   
	   }
	   else{
		   increment = -1;
		   if (value_display==-1){
			   value_display = 0;
			   // Stop cronometer
			   status = 0;
			   mode = 1;
			   // Animation 5 seconds
				stop_blink = 1;
				stop_counter = BLINK_STOP; // 5seconds
				blink_counter = BLINK_CONSTANT*4;
		   }
	   }

	   DIP[3] = value_display%10;
	   DIP[2] = (int)(value_display/10)%10;
	   DIP[1] = (int)(value_display/100)%10;
	   DIP[0] = (int)(value_display/1000)%10;


	   
     // Off anode
     decode(-1, 0);
     if (set==1 && abs(display-3)==stack_blink){
		   blink_counter -= 1;
		   if (blink_counter==-1){
				blink_counter = BLINK_CONSTANT;
		   }
		   
		   if (blink_counter>=BLINK_CONSTANT/2){
				display_on(-1);
		   }
		   else{
			   display_on(display);
		   }
	   }
	   else if (set==0 && (stop_blink==1)){
		   
		   stop_counter -= 1;
		   if (stop_counter==-1){
			   stop_blink = 0;
		   }
		   
		   // Counter blink
		   blink_counter -= 1;
		   if (blink_counter==-1){
			   blink_counter = BLINK_CONSTANT*2;
			   if (display_out==1){
					display_out = 0;
			   }
			   else{
				   display_out = 1;
			   }
		   }
		   
			if (display_out){
				display_on(display);
			}
			else{
				display_on(-1);
			}
			   
	   }
	   else{
			display_on(display);   
	   }
     decode(DIP[display], DOT[display]);
	   
	   // Multiplexing
	   display += 1;
	   if (display==5){
		   display = 0;
	   }
	   
	   delay_1ms();
	   
   }
 }
 
 void delay_1ms(){
	 //TCNT1H = 0XE0; //TEMP = 0x85
	 //TCNT1L = 0xC1;
	 
	 TCNT1H = 0xC1; //TEMP = 0x85
	 TCNT1L = 0x81;
   //TCNT1H = 0x0B; //TEMP = 0x85
	 //TCNT1L = 0xDD;
	 TCCR1A = 0x00; //Normal mode
	 TCCR1B = 0x01; //Normal mode, 1:256 prescaler
	 while ((TIFR1&(0x1<<TOV1))==0); //wait for TF0 to roll over
	 TCCR1B = 0;
	 TIFR1 = 0x1<<TOV1; //clear TOV1
 }

char get_button(){
	char mask_C = PINC&0b00001111;
	
	// Start/Stop
	if (mask_C==0b00001110){
		return 'S';
	}
	// Reset
	else if (mask_C==0b00001101){
		return 'R';
	}
	// Set
	else if (mask_C==0b00001011){
		return 'T';
	}
	// Increase
	else if (mask_C==0b00000111){
		return 'I';
	}
	else if (mask_C==0b00001111){
		pressed = 1;
		return ' ';
	}
}
 
 void display_on(int number){
   switch (number){
     case 0:
       PORTB = ~0x01;
	   break;
     case 1:
       PORTB = ~0x02;
	   break;
     case 2:
       PORTB = ~0x04;
	   break;
     case 3:
       PORTB = ~0x08;
	   break;
     default:
       PORTB = 0xFF;
	   break;
   }
 }
 
 void decode(int number, int dot){
   switch (number){
     case 0:
       PORTD = 0b00111111;
	   break;
     case 1:
       PORTD = 0b00000110;
	   break;
     case 2:
       PORTD = 0b01011011;
	   break;
     case 3:
       PORTD = 0b01001111;
	   break;
     case 4:
       PORTD = 0b01100110;
	   break;
     case 5:
       PORTD = 0b01101101;
	   break;
     case 6:
       PORTD = 0b01111101;
	   break;
     case 7:
       PORTD = 0b00000111;
	   break;
     case 8:
       PORTD = 0b01111111;
	   break;
     case 9:
       PORTD = 0b01101111;
	   break;
     default:
       PORTD = 0x00;
   }
   PORTD |= (dot<<7);
 }