/* filename ******* Motor.C ******************* 
   demonstration of the DC motor, incremental control

   This example accompanies the book
     "Embedded Microcomputer Systems: Real Time Interfacing", Brooks-Cole, copyright (c) 2000,
      Jonathan W. Valvano 5/4/99

   Interface between the TExaS simulator running a MC68HC11 EVB
      with ICC11 freeware compiler 
   TExaS Copyright 1999 by Jonathan W. Valvano 
   for more information about ICC11 
      see http://www.imagecraft.com
   You may use this file without restrictions

   PortB connected to 8-bit D/A delivers power to motor
   PE2 8 bit A/D reads speed from tachometer */

#include "HC11.h"
unsigned char power,speed;
#define SetPoint 128
void main(void){  
  power=0;
  OPTION=0x80;  /* turn on A/D power */
  while(1){
    PORTB=power; /* output to actuator */
    ADCTL=2;     /* 4 conversions on channel 2 */
    while((ADCTL&0x80)==0){};
    speed=ADR1;
    if(speed<SetPoint){ /* too slow */
    	if(power<255) power++;
    }
    else{  /* too fast */
    	if(power>1) power--;
    }
  }
}
void resetVectors(void){
/* not really a function,  but this must be last */
  asm(" org $FFFE");
  asm(" FDB __start");
  asm(" org $FC00"); /* puts rts in a harmless place */
/* string constants also placed here */
/* the value FC00 means you can have up to 1000 characters of strings  */
}