/************************************************************************
                                                                      
                        Drehgeber   
					                        
                    
                                                                      
              Author: ing. Richard Szymanski                          

              target: ATmega48, -88, -168  
			  
			  Frequenz: intern 8 MHz
			                                       
************************************************************************/


#define 	F_CPU 8000000UL

#include <stdlib.h> 
#include <avr/io.h>

#include <util/delay.h>

#include <avr/interrupt.h>

#include "HD44780.c"

char str1[20];

int count;

//------------------------------------------------------------------------------------------------------------------------------
//------------------------------------------------------------------------------------------------------------------------------

void EXT_INT_0_1_init(void)
{
	DDRD = 0b11110011;                                     // Set PD2;3 = Input, Others Output
	EIMSK |= (1<<INT1)|(1<<INT0);                          //enable external interrupt 0 and 1
}

//-------------------------------------------------------------------------------------------------------------


//                  ENC_A u -B sind die beiden Encoder Eingänge  
    
//      (  3 Pin's ... Mitte an GND  und die 2 Pins mit 100 nF auch an GND wegen ENTPRELLUNG ! ! ! ...)


#define ENC_A (PIND & 1<<PIND2)  // PIND.2
#define ENC_B (PIND & 1<<PIND3)  // PIND.3


// Interrupt-Routine 1  -------------------------------------------------------------------
ISR(INT0_vect)
{
	//external interupt on INT0
			
		switch (ENC_A + ENC_B)
	{
	  case 0:   if (EICRA==0x0E) count--; else count++;  
	          break; 
	}
	
	EICRA  = 0x0A;	
}



// Interrupt-Routine 2  --------------------------------------------------------------------
ISR(INT1_vect)
{
	//external interupt on INT1
	
	switch (ENC_A + ENC_B)
	{
	case 0:  if (EICRA==0x0A) count++; else count--;                  
	     break;	 	
	}
		
	EICRA  = 0x0E;	
}


int main( void ) 
{
	
	count = 0;
	
	EXT_INT_0_1_init();
	
 	LCD_Initialize();

	
sei();


for(;;)
   {
	
	dtostrf(count,3,0,str1);
	
	LCD_GoTo(0,0);               // LCD Ausgabe in 1-te Zeile
	LCD_WriteText("Encoder-Impuls :");
	LCD_GoTo(0,1);               // LCD Ausgabe in 2-te Zeile
	LCD_WriteText("                ");

	LCD_GoTo(5,1);               // Go to Second Line
	LCD_WriteText(str1);

   _delay_ms(50);

	}	
		
}