/*                       ATmega32 - 40 PIN DIP LAYOUT FOR LCD- 
                                      _______________________
                                      [ 1]PB0         PA0[40] 
                                      [ 2]PB1         PA1[39]
                                      [ 3]PB2         PA2[38] 
                                      [ 4]PB3         PA3[37] 
                                      [ 5]PB4         PA4[36] 
                                      [ 6]PB5         PA5[35] 
                                      [ 7]PB6         PA6[34] 
                                      [ 8]PB7         PA7[33] 
                             RESET -> [ 9]RST        AREF[32] <- +5V VCC
                            5V VCC -> [10]VCC         GND[31] <- GROUND
                            GROUND -> [11]GND        AVCC[30] <- +5V VCC
                       16 MHZ XTAL -> [12]XTAL1       PC7[29] -> LCD DATA 7
                       16 MHZ XTAL -> [13]XTAL2       PC6[28] -> LCD DATA 6
                                      [14]PD0         PC5[27] -> LCD DATA 5
                                      [15]PD1         PC4[26] -> LCD DATA 4
                     encoder 1        [16]PD2         PC3[25] -> LCD E  
                     encoder 2        [17]PD3         PC2[24] -> LCD RS 
                                      [18]PD4         PC1[23] -> LCD RW 
                                      [19]PD5         PC0[22]    not connected 
                                      [20]PD6         PD7[21]  
                                      ______________________                         */

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/signal.h>
#include "global.h"
#include "rprintf.h"
#include "lcd.h"
#include "timer.h"
 
void setupEncoder(void);
void updatePos(void);
int position;           // note that this is signed
unsigned char oldstate; // for quadrature decoding

int main(void)  {
        // initialize the timer system
        timerInit();
	// initialize LCD on PortC
	lcdInit();
	// direct printf output to LCD
	rprintfInit(lcdDataWrite);
 	lcdClear();
	setupEncoder();
	sei();
 
	while (1) {
//	PORTA = position >> 8; // example use of the result 
                            // try sending it to an lcd!
	lcdGotoXY(0,1);
	rprintf("Pos - %d ",position);   
	}
}
 
void setupEncoder() {
 
  // clear position
  position = 0; 
 
  // we need to set up int0 and int1 to 
  // trigger interrupts on both edges
  MCUCR = (1<<ISC10) | (1<<ISC00);
 
  // then enable them.
  GICR  = (1<<INT0) | (1<<INT1);
 
  // don't forget to turn on interrupts!
}
 
#define ERROR 0
signed char offsets[] = {
/* 0000 */   0,
/* 0001 */  +1,
/* 0010 */  -1,
/* 0011 */   ERROR,
/* 0100 */  -1,
/* 0101 */   0,
/* 0110 */   ERROR,
/* 0111 */  +1,
/* 1000 */  +1,
/* 1001 */   ERROR,
/* 1010 */   0,
/* 1011 */  -1,
/* 1100 */   ERROR,
/* 1101 */  -1,
/* 1110 */  +1,
/* 1111 */   0
   };
 
SIGNAL (SIG_INTERRUPT0) {  // fix this signal name!!! INT0
  updatePos();
}
 
SIGNAL (SIG_INTERRUPT1) { // fix this signal name!!! INT1
  updatePos();
}
 
 
void updatePos() {
 unsigned char temp;
/* get the bits        PIND     = XXXXiiXX
   clear space       & 0x0C     = 0000ii00
   or in old status  | oldstate = XX00iijj
   clean up          & 0x0F     = 0000iijj  */  
 
 temp = ((PIND & 0x0C) | oldstate) & 0x0F;
 oldstate = (temp >> 2);                     // update oldstate
 position += offsets[temp];                  // update position
	if (position == 2016) position = 0; 
	if (position == -1) position = 2016;
//	if (position == 2016) position = 0;  //rues first thought
//	if (position == 16384) position = 2016; 

}