/*
 * i2c_test_attiny85.c
 *
 * Created: 12/11/2021 15:26:38
 * Author : 40008304
 */ 

#include <avr/io.h>
#define F_CPU 1000000
#include <util/delay.h>

#define FRONT	0x51
#define RIGHT	0x52
#define LEFT	0x53
#define NOTHING	0x54
#define ERROR	0xF0
#define VOLTMIN	1

void led1_init(void);
void led2_init(void);
void led1_stop(void);
void led2_stop(void);
void ADC_init(void);
char ADC_read_value(void);
float ADC_averaging(void);
float measureLed1(void);
float measureLed2(void);
char compareLed(void);

int main(void)
{
    DDRB |= (1<<PB0);
	DDRB |= (1<<PB2);
	led2_init();
	led1_init();
	ADC_init();
	char sendingData;
    while (1) 
    {
		sendingData = compareLed();
		switch(sendingData)
		{
			case NOTHING:
				PORTB |= (1<<PINB0);	//les deux sont eteintes
				PORTB |= (1<<PINB2);
				break;
			case FRONT:
				PORTB &= ~(1<<PINB0);	//les deux sont allumees
				PORTB &= ~(1<<PINB2);
				break;
			case RIGHT:
				PORTB &= ~(1<<PINB0);	//a droite allumee (led0)
				PORTB |= (1<<PINB2);
				break;
			case LEFT:
				PORTB |= (1<<PINB0);	//a gauche allumee (led1)
				PORTB &= ~(1<<PINB2);
				break;
			default:
				break;
		};
    };
}

void led1_init(void)
{
	DDRB |= (1<<PB1);
	TCCR1|=(1<<CTC1)|(1<<COM1A0);		//on active le mode CTC en comparant OCR1C, COM1A1 � 1 pour desactiver /OC1A
	OCR1C=16;							//d'apres retroingenieurie OCR1C=16
	TCCR1|=(1<<CS10);					//on active la clock avec CS10 = 1, pas de prediv (plus precis pour haute freq)
}

void led2_init(void)
{
	DDRB |= (1<<PB4);
	GTCCR|=(1<<COM1B0);					//COM1B0 a 1 pour desactiver /OC1A
	OCR1B=16;							//d'apres retroingenieurie OCR1B=16
	TCCR1|=(1<<CS10);					//on active la clock avec CS10 = 1, pas de prediv (plus precis pour haute freq)
}

void led1_stop(void)
{
	TCCR1 &= ~(1<<COM1A0);
}

void led2_stop(void)
{
	GTCCR &= ~(1<<COM1B0);
}

void ADC_init(void)
{
	DDRB &=~(1<<PB3);										//Pin B3 en entree
	ADMUX |= (1<<MUX1)|(1<<MUX0)|(1<<ADLAR);				//MUX = 0010 donc sortie PB4 et ADLAR a 1 pour avoir les bits de poids fort en premier
	ADCSRA |= (1<<ADEN)|(1<<ADPS2);							//On divise 1Mhz par 16 (62.5 KHz) < 200 KHz, ADEN conversion autorisee
};

char ADC_read_value(void)
{
	ADCSRA|=(1<<ADSC);
	while(ADCSRA & (1<<ADSC));
	return ADCH;
};

float ADC_averaging(void)
{
	float valeur_finale=0;
	char precision;
	for(precision = 75; precision > 0 ; precision --)
	{
		valeur_finale = valeur_finale +(((ADC_read_value() * 0.01961) - valeur_finale) / 15);
	}
	return valeur_finale;
};

float measureLed1(void)
{
	float adcLed;
	led2_stop();
	led1_init();
	_delay_ms(250);
	adcLed=ADC_averaging();
	_delay_ms(250);
	return adcLed;
};

float measureLed2(void)
{
	float adcLed;
	led1_stop();
	led2_init();
	_delay_ms(250);
	adcLed=ADC_averaging();
	_delay_ms(250);
	return adcLed;
};

char compareLed(void)
{
	float adcLed1 = measureLed1();
	float adcLed2 = measureLed2();
	float adcCompare = adcLed1 - adcLed2;
    if (adcCompare < -VOLTMIN)	// adcLed2 > adcLed1
	{
		return LEFT;
	}
	else if (adcCompare > VOLTMIN)
	{
		return RIGHT;
	}
	else
	{
		if((adcLed1 > VOLTMIN) && (adcLed2 > VOLTMIN))
		{
            return FRONT;
		}
		else
		{
            return NOTHING;
		};
	};
};