/***************************************************************************/
/* Stepper Motor Driver                                                    */
/*                                                                         */
/* Stepper.c                                                               */
/*                                                                         */
/*  Version :   1.0                                                        */
/*                                                                         */
/*       By :   Julian Winpenny                                            */
/*                                                                         */
/*     Date :   25/6/2000                                                  */
/*                                                                         */
/*  Purpose :   Illustrate Driving a Stepper Motor                         */
/*              Runs Clockwise slow then Anticlockwise fast                */
/*                                                                         */
/*     Notes:   Stepper motor driving transistors                          */
/*              connected to 4 bits Port B                                 */
/*                                                                         */
/*              Add a Photo switch to detect                               */
/*              position.                                                  */
/*                                                                         */
/***************************************************************************/


void StepIt( char Direction, char Speed );


char stepper[] = {5,9,10,6};
char cPos;


#define Clockwise 0;
#define AntiClockwise 3;


void main(void)
{

int x;

// Set up the PIC ports etc.

   set_bit(STATUS, RP0);
   set_tris_b(0);
   clear_bit(STATUS, RP0);



   while(1)
   {

        for ( x=0; x < 100 ; x++ )
        {

           StepIt( Clockwise, 50 );
      
        }   
     
        delay_s(2);
   
        for ( x=0; x < 200 ; x++ )
        {

           StepIt( AntiClockwise, 10 );
      
        }   
   
   
   }  




}


/******************************/
/* Move the Motor             */
/*                            */
/*                            */
/******************************/
void StepIt( char Direction, char Speed )
{

 // Initialise if needed
 
 if (  cPos > 3  ) cPos = 0;
 
   
          // Do each step sequence
          output_port_b(stepper[cPos]);

          // Set speed
          delay_ms( Speed );
          
          switch ( Direction )
          {

                 case Clockwise: 
                 
                                  if( cPos++ == 4 ) cPos = 0; 
                                  break;
             
          
              case AntiClockwise: 
              
                                  if( cPos-- == 0 ) cPos = 3; 
              
                                  break;
           
          }                   


}