// Stepper3.C

// Global Variables
const unsigned char MSG[16] = "Stepper3.C      ";
unsigned char TABLE[4] = {1, 2, 4, 8};
int DIR, SPEED, STEP, N, TIME;

// Subroutine Declarations
#include <pic18.h>
#include "LCD_PortD.C"

// High-priority service
void interrupt IntServe(void)
{
   if (TMR2IF) {
      TIME = TIME + 1;
      if (RB4) { DIR = 1;  SPEED =  20; }
      if (RB3) { DIR = 1;  SPEED = 100; }
      if (RB2) { DIR = 0;  SPEED = 100; }
      if (RB1) { DIR =-1;  SPEED = 100; }
      if (RB0) { DIR =-1;  SPEED =  20; }

      N = (N + 1) % SPEED;
      if (N == 0) {
         STEP = STEP + DIR;
         PORTC = TABLE[STEP %  4];
         }
      TMR2IF = 0;
      }
   }



        
// Main Routine

void main(void)
{
   int i;

   TRISA = 0;
   TRISB = 0xFF;
   TRISC = 0;
   TRISD = 0;
   TRISE = 0;
   ADCON1 = 0x0F;

   STEP = 0;
   DIR = 1;
   SPEED = 100;

   LCD_Init();
   LCD_Move(0,0);
   for (i=0; i<16; i++) LCD_Write(MSG[i]);
   Wait_ms(100);

// initialize Timer2

   T2CON = 0x4D;
   PR2 = 249;
   TMR2ON = 1;
   TMR2IE = 1;
   PEIE = 1;

   GIE = 1;

   while(1) {
      LCD_Move(1,0);   LCD_Out(TIME,3, 5);
      LCD_Move(1,8);   LCD_Out(STEP,0, 5);
      }
  
 }