#include	<stdint.h>
#include 	<avr/io.h>
#include 	<avr/interrupt.h>

#define		F_CPU 12000000	//CPU-Takt
#include	<util/delay.h>	
#define		BAUD 9600		//Bautrate
#define 	UART_BAUD_RATE	((F_CPU/16/BAUD)-1)				//Werte für Baudregister berechnen
#define 	BAUD_REAL	(F_CPU/(16*(UART_BAUD_RATE+1)))		//Reale Baudrate
#define 	BAUD_ERROR	( (BAUD_REAL*1000)/BAUD)			//Fehler in Promille

//Falls Baudrate falsch berechnet oder ähnliches->Fehler ausgeben
#if		((BAUD_ERROR < 990)	||	(BAUD_ERROR > 1010))
	#error 	Fehler Baudrate größer 1% !
#endif


#define		K_Port		PORTC	//Nachkommastelle entweder 0 oder 5
#define		Komma0		PC4
#define		Komma5		PC5

#define		LED_Port	PORTD	//Leds
#define		LED_rot		PD4
#define		LED_gruen	PD3

#define		T_Port		PIND	//Taster
#define		Taster_h	PD7	//Spannung hoch
#define		Taster_r	PD6	//Spannung runter
#define		Taster_b	PD5	//bestätigen

#define		Z1_Port		PORTB	//erste Zahl an PortB
#define		Z2_Port		PORTC	//zweite Zahl an PortC


/************************************************
*	Funktionsprototypen
*************************************************/


//AVR initialisieren
void 	Init_AVR(void);


//***********************************************
//USART initialisieren
void	USART_Init(void);


//***********************************************
//Daten über USART senden
void	USART_Transmit(unsigned char data);


//***********************************************
//Taster abfragen
uint8_t	Taster_Check(void);


//***********************************************
//Spannung auf 7-Segment ausgeben
void	Display_V(uint16_t Voltage);


//***********************************************
//Taster entprellen
inline uint8_t debounce(volatile uint8_t *port, uint8_t pin)
{
	if (!(*port & (1<<pin)) )
	{
		//Pin wurde auf Masse gezogen, x ms warten
		_delay_ms(50);
		//_delay_ms(50);
		if (*port & (1<<pin) )
		{
			//Zeit zum loslassen geben
			_delay_ms(50);
			//_delay_ms(50);
			return 1;
		}
	}
	return 0;
}


/************************************************
*	Hauptprogramm
*************************************************/


volatile uint16_t V_set = 140;		//eingestellte Spannung
uint8_t Taster = 0;

int main(void)
{

	Init_AVR();

	//USART_Init();

	while(1)		//Hauptschleife
	{
		Taster	=	Taster_Check();		//Taster abfragen

		switch (Taster){

		//Taster hoch wurde gedrückt
		case 1:	if (V_set == 205)
				{
					V_set = 208;
				}
				else
				{
					if (V_set < 205)
					{
						V_set += 5;
					}
				}

				break;

		//Taster runter wurde gedrückt
		case 2: if (V_set == 208)
				{
					V_set = 205;
				}
				else
				{
					if (V_set > 80)
					{
						V_set -= 5;
					}
				}

				break;

		//Spannung über RS232 senden
		case 3: //rote LED ausschalten
				LED_Port	&=	~(1<<LED_rot);
				//senden

				//grüne LED einschalten
				LED_Port	|=	(1<<LED_gruen);

				break;
		}

		//Spannung ausgeben
		Display_V(V_set);

	}

return 0;
}

/************************************************
*	Unterfunktionen
*************************************************/


//AVR initialisieren
void Init_AVR(void){
	//Ports definieren

	//PB1..PB4 Ausgang
	DDRB	=	0xFF;
	//PORTB	&=	~(	(1<<PB1)	|	(1<<PB2)	|	(1<<PB3)	|	(1<<PB4)	);
	PORTB	= 	0x00;

	//PC0..PC5 Ausgang
	DDRC	=	0xFF;
	//PORTC	&=	~(	(1<<PC0)	|	(1<<PC1)	|	(1<<PC2)	|	(1<<PC3)	|	(1<<PC4)	|	(1<<PC5)	);
	PORTC	=	0x00;

	//PD3..PD4 Ausgang, PD5..PD7 Eingang
	DDRD	= 	0xFF;
	DDRD	&=	~(	(1<<PD5)	|	(1<<PD6)	|	(1<<PD7)	);
	PORTD	= 	0x00;
	//DDRD	=	0x18;
	//PORTD	&=	~(	(1<<PD3)	|	(1<<PD4)	);
	
	//PD5..PD7 Eingang
	//DDRB	&=	~(	(1<<PD5)	|(1<<PD6)	|	(1<<PD7)	);
	
	//Interrupts erlauben
	//sei();	
}


//***********************************************
//UART initialisieren
void USART_Init(void){
	//Set Baudrate
	UBRR0H	=	(unsigned char) (UART_BAUD_RATE>>8);
	UBRR0L	= 	(unsigned char) (UART_BAUD_RATE);

	//Enable Receiver und Transmitter und Receive-Complete-Interrupt
	UCSR0B	|=	(1<<RXEN0)	|	(1<<TXEN0)	|	(1<<RXCIE0);

	//Format: 8 Daten-Bit, 2 Stop-Bit
	UCSR0C	|=	(1<<USBS0)	|	(3<<UCSZ00);

	//laut Datenblatt
	UCSR0A	|=	(1<<RXC0);
}


//***********************************************
//UART Transmit
void USART_Transmit(unsigned char data){
	//warten, dass Sende-Puffer leer ist
	while (!(UCSR0A & (1<<UDRE0)) );

	//Daten in Puffer
	UDR0	=	data;
}


//***********************************************
//Taster abfragen
uint8_t	Taster_Check(void){

volatile uint8_t taster = 0;

	if (debounce(&T_Port,Taster_h))
	{
		taster = 1;
		//grüne LED aus, rote ein
		LED_Port	&=	~(1<<LED_gruen);
		LED_Port	|=	(1<<LED_rot);
	}
	
	if (debounce(&T_Port,Taster_r))
	{
		taster = 2;
		//grüne LED aus, rote ein
		LED_Port	&=	~(1<<LED_gruen);
		LED_Port	|=	(1<<LED_rot);
	}

	if (debounce(&T_Port,Taster_b))
	{
		taster = 3;
	}

	return taster;
}


//***********************************************
//Spannung auf 7-Segment ausgeben
void	Display_V(uint16_t Voltage){

	K_Port	&=	~((1<<Komma0)	|	(1<<Komma5)	);
	Z1_Port	= 0;
	Z2_Port = 0;

	switch (Voltage){
		
		case 80:	Z1_Port = 0;
					Z2_Port	= 8;
					K_Port	|=	(1<<Komma0);

				break;

		case 85:	Z1_Port = 0;
					Z2_Port	= 8;
					K_Port	|=	(1<<Komma5);

				break;

		case 90:	Z1_Port = 0;
					Z2_Port	= 9;
					K_Port	|=	(1<<Komma0);

				break;

		case 95:	Z1_Port = 0;
					Z2_Port	= 9;
					K_Port	|=	(1<<Komma5);

				break;

		case 100:	Z1_Port = 2;
					Z2_Port	= 0;
					K_Port	|=	(1<<Komma0);

				break;

		case 105:	Z1_Port = 2;
					Z2_Port	= 0;
					K_Port	|=	(1<<Komma5);

				break;

		case 110:	Z1_Port = 2;
					Z2_Port	= 1;
					K_Port	|=	(1<<Komma0);

				break;

		case 115:	Z1_Port = 2;
					Z2_Port	= 1;
					K_Port	|=	(1<<Komma5);

				break;

		case 120:	Z1_Port = 2;
					Z2_Port	= 2;
					K_Port	|=	(1<<Komma0);

				break;

		case 125:	Z1_Port = 2;
					Z2_Port	= 2;
					K_Port	|=	(1<<Komma5);

				break;

		case 130:	Z1_Port = 2;
					Z2_Port	= 3;
					K_Port	|=	(1<<Komma0);

				break;

		case 135:	Z1_Port = 2;
					Z2_Port	= 3;
					K_Port	|=	(1<<Komma5);

				break;

		case 140:	Z1_Port = 2;
					Z2_Port	= 4;
					K_Port	|=	(1<<Komma0);

				break;

		case 145:	Z1_Port = 2;
					Z2_Port	= 4;
					K_Port	|=	(1<<Komma5);

				break;
		
		case 150:	Z1_Port = 2;
					Z2_Port	= 5;
					K_Port	|=	(1<<Komma0);

				break;

		case 155:	Z1_Port = 2;
					Z2_Port	= 5;
					K_Port	|=	(1<<Komma5);

				break;

		case 160:	Z1_Port = 2;
					Z2_Port	= 6;
					K_Port	|=	(1<<Komma0);

				break;

		case 165:	Z1_Port = 2;
					Z2_Port	= 6;
					K_Port	|=	(1<<Komma5);

				break;

		case 170:	Z1_Port = 2;
					Z2_Port	= 7;
					K_Port	|=	(1<<Komma0);

				break;

		case 175:	Z1_Port = 2;
					Z2_Port	= 7;
					K_Port	|=	(1<<Komma5);

				break;

		case 180:	Z1_Port = 2;
					Z2_Port	= 8;
					K_Port	|=	(1<<Komma0);

				break;

		case 185:	Z1_Port = 2;
					Z2_Port	= 8;
					K_Port	|=	(1<<Komma5);

				break;

		case 190:	Z1_Port = 2;
					Z2_Port	= 9;
					K_Port	|=	(1<<Komma0);

				break;

		case 195:	Z1_Port = 2;
					Z2_Port	= 9;
					K_Port	|=	(1<<Komma5);

				break;

		case 200:	Z1_Port = 4;
					Z2_Port	= 0;
					K_Port	|=	(1<<Komma0);

				break;

		case 205:	Z1_Port = 4;
					Z2_Port	= 0;
					K_Port	|=	(1<<Komma5);

				break;

		case 208:	Z1_Port = 4;
					Z2_Port	= 0;
					K_Port	|=	((1<<Komma5)	|	(1<<Komma0));

				break;

		default:	break;
	}
}