//Toggling PE2 to activate the Relay for Dragon12 Plus Trainer Board 
//PE2 of PORTE is connected to Relay on Dragon12+ board
//This program toggles PE2 to turn on and off the Relay(you hear click sound closing and opening the relay)   
//For Relay See Chapter 15 of HCS12 book by Mazidi & Causey
//If you use this relay to control an external device such as horn and lamp use external power as shown in chapter 15.  


#include <hidef.h>      /* common defines and macros */
#include "derivative.h"      /* derivative-specific definitions */


void MSDelay(unsigned int);
void main(void) 
{
  /* put your own code here */
  
       
    DDRE = DDRE | 0b00000100;    // PE2 as output 
     
    for (;;) 			
      {
       PORTE = PORTE | 0b00000100;     //make PE2=1 to turn on relay
       MSDelay(500);         //change the delay size to see what happens
       PORTE = PORTE & 0b11111011;      //Make PE2=0 to turn off relay
      MSDelay(500);         //change delay size....

      }

}

void MSDelay(unsigned int itime)  //msec delay
  {
    unsigned int i; unsigned int j;
    for(i=0;i<itime;i++)
      for(j=0;j<4000;j++);
  }