/*
 * rotaryEncoder.c
 *
 * Created: 16/12/2021 16:34:05
 *  Author: n0x
 */ 

#include "rotaryEncoder.h"

#define ROTA PORTC7
#define ROTB PORTC6
#define ROTBUTTON PORTC5

/* enums */
enum{
	S2, S3, S4, S5, S6, S7,
	INIT, WAIT
	} RotaryState = INIT; /* Emus for the stoplight task (task 3) */

int16_t count;

void 
drehgeber_init(void)
{
	DDRC &= ~(7<<DDC5);			/* Set bit 5-7 of Data Direction Register C as input */
	PORTC |= (7<<PORTC5);		/* Initialize bit 5-7 of PORTC as for pull up resistor */
	
	/* With Timer */
// 	TCCR2A |= (1<<WGM21);
// 	TCCR2B |= (3<<CS20);
// 	TIMSK2 |= (1<<OCIE2A);
// 	OCR2A = 250 - 1;
	
	/* With external interrupt */
	PCICR |= (1<<PCIE2);
	PCMSK2 |= (1<<PCINT23)|(1<<PCINT22);
}

// ISR(TIMER2_COMPA_vect)
// {
// 	drehgeber_process();
// }

ISR(PCINT2_vect)
{
	drehgeber_process();
}

void 
drehgeber_process(void)
{	
	uint8_t a,b, enc;
	a = ((PINC & (1<<ROTA)) == 0);
	b = ((PINC & (1<<ROTB)) == 0)<<1;
	enc=a+b;
	
	switch(RotaryState)
	{
		case INIT:
		RotaryState = WAIT;
		break;
		
		case WAIT:
		if(enc == 1)
		{
			RotaryState = S2;
		}
		if(enc == 2)
		{
			RotaryState = S5;
		}
		break;
		
		case S2:
		if(enc == 3)
		{
			RotaryState = S3;
		}
		if(enc == 0)
		{
			RotaryState = WAIT;
		}
		break;
		
		case S3:
		if(enc == 2)
		{
			RotaryState = S4;
		}
		if(enc == 1)
		{
			RotaryState = S2;
		}
		break;
		
		case S4:
		if(enc == 0)
		{
			count++;
			RotaryState = WAIT;
		}
		if(enc == 3)
		{
			RotaryState = S3;
		}
		break;
		
		case S5:
		if(enc == 3)
		{
			RotaryState = S6;
		}
		if(enc == 0)
		{
			RotaryState = WAIT;
		}
		break;
				
		case S6:
		if(enc == 1)
		{
			RotaryState = S7;
		}
		if(enc == 2)
		{
			RotaryState = S5;
		}
		break;
		
				
		case S7:
		if(enc == 0)
		{
			count--;
			RotaryState = WAIT;
		}
		if(enc == 3)
		{
			RotaryState = S6;
		}
		break;
	}
}

int16_t drehgeber_get(void)
{
	return count;
}