// Stepper3.C

// Global Variables
const unsigned char MSG[16] = "Stepper4.C      ";
unsigned char TABLE[4] = {1, 2, 4, 8};
int REF, 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) REF = 200;
      if (RB3) REF = 150;
      if (RB2) REF = 100;
      if (RB1) REF =  50;
      if (RB0) REF =   0;

      N = (N + 1) % 20;
      if (N == 0) {
         if (STEP < REF) STEP += 1;
         if (STEP > REF) STEP -= 1;
         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;
   REF  = 0;
   
   LCD_Init();
   LCD_Move(0,0);
   for (i=0; i<16; i++) LCD_Write(MSG[i]);
   Wait_ms(1000);
   LCD_Inst(0x01);

// initialize Timer2

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

   GIE = 1;

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