____________________________________MAIN_____________________________________________________________

#define F_CPU 1000000UL  // standard integrated oscillator
#include <avr/io.h>
#include <util/delay.h>
#include <move.h>

#define PORT_ON(port,pin) port |= (1<<pin)
#define PORT_OFF(port,pin) port &= ~(1<<pin)

void ioinit(void);
void lightseeker(void);
void RGB(int Red, int Green, int Blue);

int analogRead(int Pin);


int leftval = 0;
int rightval = 0;

int mode = 0; // mode == 0 : lightseeker

//======================
int main (void)
{
	ioinit(); //Setup IO pins and defaults
	
	while(bit_is_set(PIND, 5));
	
	while(1){
		if (mode == 0){
			RGB(1,0,0);
			_delay_ms(500);
			while (bit_is_set(PIND, 5)){
				lightseeker();
			}
			mode++;
		}else if (mode == 1){
			RGB(0,1,0);
			_delay_ms(500);
			while  (bit_is_set(PIND, 5)){
				
			}
			mode++;
		}else if (mode == 2){
			RGB(0,0,1);
			_delay_ms(500);
			while  (bit_is_set(PIND, 5)){
				
			}
			mode++;
		}
		
		if (mode == 3){
			mode = 0;
		}
	}
}

void ioinit (void)
{           //76543210  PINS
	DDRD =  0b00011111;                           //set inputs/outputs
	DDRB =  0b11000000;
	PORTD = 0b00100000;                           //enable internal pullup
	
	RGB(1,0,0);
	_delay_ms(500);
	RGB(0,1,0);
	_delay_ms(500);
	RGB(0,0,1);
	_delay_ms(500);
	RGB(0,0,0);
}

void RGB(int Red, int Green, int Blue){   //Status LED not added yet coming soon
	if (Red == 1){
		PORT_ON(PORTD, 4);
	}else{
		PORT_OFF(PORTD, 4);
	}

    if (Green == 1){
	    PORT_ON(PORTB, 6);
	}else{
	    PORT_OFF(PORTB, 6);
    }
	
	if (Blue == 1){
		PORT_ON(PORTB, 7);
    }else{
		PORT_OFF(PORTB, 7);
	}
}



int analogRead(int Pin){

	unsigned int adc_value; // Variable to hold ADC result

	ADCSRA = (1<<ADPS1) | (1<<ADPS0); // prescaler
	ADCSRA |= (1<<ADEN);
	
	if (Pin == 5){
		ADMUX = 0x05;
		}else if (Pin == 4){
		ADMUX = 0x04;
	}

	ADCSRA |= (1<<ADSC); // Start conversion
	while (ADCSRA & (1<<ADSC)); // wait for conversion to complete
	adc_value = ADCW; //Store ADC value
	
	return adc_value;
}

void lightseeker(void){
	leftval = analogRead(5);                 //checking the LDR's
	rightval = analogRead(4);
	if ( ((leftval + 7) > rightval && (leftval - 7) < rightval) | ((rightval + 7) > leftval && (rightval - 7) < leftval) ){
		forward();
		}else if (leftval < rightval){
		right();
		}else if (leftval > rightval){       // decide the way
		left();
	}
}

___________________________________________________________move.h___________________________________________________________

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

void motor1_f(void);
void motor1_b(void);
void motor2_f(void);
void motor2_b(void);

void forward(void);
void backward(void);
void left(void);
void right(void);
void turnleft(void);
void turnright(void);
void stop(void);

void motor1_b(void)
{
	PORTD |= _BV(PD0);
}

void motor1_f(void)
{
	PORTD |= _BV(PD1);
}

void motor2_b(void)
{
	PORTD |= _BV(PD2);
}

void motor2_f(void)
{
	PORTD |= _BV(PD3);
}

void forward(void)
{
	motor1_f();
	motor2_f();
	_delay_ms(1);
	PORTD &= ~_BV(PD1);
	PORTD &= ~_BV(PD3);
}

void backward(void)
{
	motor1_b();
	motor2_b();
	_delay_ms(10);
	PORTD &= ~_BV(PD0);
	PORTD &= ~_BV(PD2);
}

void left(void)
{
	motor2_f();
	_delay_ms(1);
	PORTD &= ~_BV(PD3);
}

void right(void)
{
	motor1_f();
	_delay_ms(1);
	PORTD &= ~_BV(PD1);
}

void turnleft(void)
{
	motor1_b();
	motor2_f();
	_delay_ms(10);
	PORTD &= ~_BV(PD0);
	PORTD &= ~_BV(PD3);
}

void turnright(void)
{
	motor1_f();
	motor2_b();
	_delay_ms(10);
	PORTD &= ~_BV(PD1);
	PORTD &= ~_BV(PD2);
}
void stop(void)
{
	PORTD &= ~_BV(PD0);
	PORTD &= ~_BV(PD1);
	PORTD &= ~_BV(PD2);
	PORTD &= ~_BV(PD3);
}