// main.c

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

// numero di stati
#define STATI_MAX 4

// debounce milliseconds
#define DEB_MSEC 20

// blinking period
#define BLINK_PERIOD 1000

// configurazione LED
#define LED2_PORT PORTC
#define LED2_DDR  DDRC
#define LED2_PP   (1<<PC4)

#define LED3_PORT PORTD
#define LED3_DDR  DDRD
#define LED3_PP   (1<<PD4)

#define LED4_PORT PORTD
#define LED4_DDR  DDRD
#define LED4_PP   (1<<PD5)

#define LED5_PORT PORTD
#define LED5_DDR  DDRD
#define LED5_PP   (1<<PD6)


// configurazione tasti
#define KEY_UP_PIN PIND
#define KEY_UP_PP  (1<<PD2)

#define KEY_DN_PIN PIND
#define KEY_DN_PP  (1<<PD3)

// macros LED
#define LED2_INIT() LED2_DDR|=LED2_PP
#define LED2_ON()   LED2_PORT|=LED2_PP
#define LED2_OFF()  LED2_PORT&=~LED2_PP

#define LED3_INIT() LED3_DDR|=LED3_PP
#define LED3_ON()   LED3_PORT|=LED3_PP
#define LED3_OFF()  LED3_PORT&=~LED3_PP

#define LED4_INIT() LED4_DDR|=LED4_PP
#define LED4_ON()   LED4_PORT|=LED4_PP
#define LED4_OFF()  LED4_PORT&=~LED4_PP

#define LED5_INIT() LED5_DDR|=LED5_PP
#define LED5_ON()   LED5_PORT|=LED5_PP
#define LED5_OFF()  LED5_PORT&=~LED5_PP


// macros bottone
#define key_up_prsd() ((KEY_UP_PIN&KEY_UP_PP) == 0)
#define key_up_rlsd() ((KEY_UP_PIN&KEY_UP_PP) != 0)
#define key_dn_prsd() ((KEY_DN_PIN&KEY_DN_PP) == 0)
#define key_dn_rlsd() ((KEY_DN_PIN&KEY_DN_PP) != 0)

// stato translazione LED
inline void LED_out(uint8_t input)
{
	switch(input)
	{
	case 0:
		LED2_ON();
		LED3_OFF();
		LED4_OFF();
		LED5_OFF();
		break;
	case 1:
		LED2_OFF();
		LED3_ON();
		LED4_OFF();
		LED5_OFF();
		break;
	case 2:
		LED2_OFF();
		LED3_OFF();
		LED4_ON();
		LED5_OFF();
		break;
	case 3:
	default:
		LED2_OFF();
		LED3_OFF();
		LED4_OFF();
		LED5_ON();
		break;
	}
}

// funzione principale
int main(void)
{
	uint8_t stato = 0;

	// inizializzare LED
	LED2_INIT();
	LED3_INIT();
	LED4_INIT();
	LED5_INIT();

	// LED lampeggiano 3x
	LED2_ON();
	LED3_ON();
	LED4_ON();
	LED5_ON();
	_delay_ms(BLINK_PERIOD);
	LED2_OFF();
	LED3_OFF();
	LED4_OFF();
	LED5_OFF();
	_delay_ms(BLINK_PERIOD); //1x
	LED2_ON();
	LED3_ON();
	LED4_ON();
	LED5_ON();
	_delay_ms(BLINK_PERIOD);
	LED2_OFF();
	LED3_OFF();
	LED4_OFF();
	LED5_OFF();
	_delay_ms(BLINK_PERIOD); // 2x
	LED2_ON();
	LED3_ON();
	LED4_ON();
	LED5_ON();
	_delay_ms(BLINK_PERIOD);
	LED2_OFF();
	LED3_OFF();
	LED4_OFF();
	LED5_OFF();
	_delay_ms(BLINK_PERIOD); // 3x

	// ciclo eterno
    for(;;)
    {
    	// premato "su"?
    	if(key_up_prsd())
    	{
    		// incrementare se inferiore
    		if(stato < (STATI_MAX - 1))
    		{
    			stato++;
    		}

    		_delay_ms(DEB_MSEC);

    		while(key_up_prsd())
    		{
    			// attesa relascio
    		}

    		_delay_ms(DEB_MSEC);
    	}

    	// premato "giu"?
    	if(key_dn_prsd())
    	{
    		// decremento si maggiore
    		if(stato > 0)
    		{
    			stato--;
    		}

    		_delay_ms(DEB_MSEC);

    		while(key_dn_prsd())
    	    {
    			// attesa relascio
    	   	}

    		_delay_ms(DEB_MSEC);
    	}

    	// uscita
    	LED_out(stato);
    }

    return(0); // mai raggiunto
}

// eof main.c