/**
 * Written by Brent Strysko for Team 1672
 * http://www.brentstrysko.com
 * http://www.team1672.com
 * All Rights Reserved
 *
 * PC5 - Relay 1
 * PC4 - Relay 2
 * PC3 - Relay 3
 * PC2 - Relay 4
 *
 * PB0 - 7 Segment 1 A
 * PB1 - 7 Segment 1 B
 * PB2 - 7 Segment 1 C
 * PB3 - 7 Segment 1 D
 *
 * PB4 - 7 Segment 2 A
 * PB5 - 7 Segment 2 B
 * PB6 - 7 Segment 2 C
 * PB7 - 7 Segment 2 D
 */
 
#define F_CPU 1000000
 
#include <avr/io.h>
#include <util/delay.h>
 
//update 7 Segment displays in respect to the time
void updateClock(unsigned char timeRemaining)
{
	unsigned char digitH = timeRemaining / 10;
	unsigned char digitL = timeRemaining % 10;
 
	PORTB = (digitH << 4) | (digitL);
}
 
//update relays in respect to the time
void updateRelays(unsigned char timeRemaining)
{
	if( (90 < timeRemaining) && (timeRemaining <= 120)) //lights strobe to the left
	{
		if(PORTC & 0x04)  //if it reached the lowest pin(Pin 2)
		{
			PORTC = (1 << PC5); //turn highest pin on
		}
		else
		{
			unsigned char temp = PORTC;
			PORTC = temp >> 1; //turn pin off and the one lower on
		}
 
	}
	else if(timeRemaining == 90)
	{
		PORTC = 1 << PC2;
	}
	else if((30 < timeRemaining) && (timeRemaining < 90)) //lights strobe to the right
	{
		if(PORTC & 0x20)  //if it reached the highest pin(Pin 5)
		{
			PORTC = (1 << PC2); //turn low pin on
		}
		else
		{
			unsigned char temp = PORTC;
			PORTC = temp << 1; //turn one pin off and the one higher on
		}
	}
	else if(timeRemaining == 30)
	{
		PORTC = 0xFF; //turn all pins on
	}
	else
	{
		PORTC = ~PORTC; //strobe the pins
	}
}
 
int main(void)
{
	//make pins on PORTS B and C outputs
	DDRB = (1 << DDB0) | (1 << DDB1) | (1 << DDB2) | (1 << DDB3) | (1 << DDB4) | (1 << DDB5) | (1 << DDB6) | (1 << DDB7);
	DDRC = (1 << DDC2) | (1 << DDC3) | (1 << DDC4) | (1 << DDC5); 
 
	PORTC = (1 << PC5);
	PORTB = 0xAA;
 
	unsigned char timeRemaining = 120;
	unsigned char counter = 0;
 
	while(1)
	{
		while(counter < 25)
		{
			if(counter == 24)
			{
				updateRelays(timeRemaining);
			}
			if(timeRemaining <= 90)
			{
				updateClock(timeRemaining);
			}
			_delay_ms(40);
			counter++;
		}
		timeRemaining--;
		counter = 0;
		if(timeRemaining == 0)
		{
			updateClock(0);
			return 0;
		}
	}
 
    return 0;
}