//Stepper Motor control using the H-Bridge on Dragon12 
//Dragon12 board comes with TI's 754410 H-bridge driver which can be used to drive stepper motor and DC motor(Google for data sheet and study it)
//On Dragon12 , PORTB and PORTP are used to control BOTH 754410 chip and 7-seg LEDs
//WE CANNOT USE BOTH 7-SEG LEDs and 754410 AT THE SAME TIME.
//J24 (on left side of CPU) is used to provide power to 7-seg LEDs driver 
//and J18 (at the bottom left side of the board by the buzzer) is used to provide power to H-bridge driver.
//ONLY ONE OF THEM SHOULD HAVE A JUMPER
//The Dragon12 is shipped with J24 (7-Seg LEDs) power enabled and nothing on J18.
//If you want to use H-Bridge you MUST move the jumper from J24 to J18. ONLY ONE OF THEM SHOULD HAVE A JUMPER

//Examine the outputs of the H-bridge at T4 Terminal block next to Reset button. They are M1,M2,M3 and M4 
//On Dragon12 the PP0 is connected to EN12 input pin of 754410.
//PB0 is connected to 1A and PB1 to 2A input pins of the 754410. That means M1 (1Y) and M2 (2Y) outputs are controlled by PB0,PB1 and PP0.
//Also the PP1 is connected to EN34 pin of 754410.
//PB2 is connected to 3A and PB3 to 4A input pins of the 754410. That means M3 (3Y) and M4 (4Y) outputs are controlled by PB2,PB3 and PP1.


//Steps to connect and run this program to control stepper motor
//1)move jumper from J24 to J18 to power the 754410 chip
//2)Connect an external 5V-9V DC power to the COM leads of the stepper motor 
//3)Connect Mx (M1,M2,M3, and M4 on T4 Terminal block) to the stepper motor leads as follow: 
//  M1 to blue, M2 to white, M3 to yellow, and M3 to red lead
//Now, power your Dragon12 board and 
//Compile (F7), Download (F5) and run(F5), 
//This program will rotate the stepper motor counter clockwise(CCW) continuosly,

//Written and tested by M. Mazidi. 
//for stepper motor control see chapter 15 of HCS12 book by Mazidi & Causey.    

#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 */
  
  DDRB = 0x0F;      //PORTB0-PORTB3  as output 
  DDRP = 0x03;      //PORTP0 and PORTP1 as output for 12EN=1 and 34EN=1                                  ````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````
  
  PORTB=0b00000000; // start with all off
  PTP=0b00000011;   //Turn on both 12EN and 34EN Enables for 754410 chip  
 
for(;;) 
   {
  
  PORTB=0b00000011;   
  MSDelay(50);  
  PORTB=0b00000110;    
  MSDelay(50);  
  PORTB=0b00001100;    
  MSDelay(50);  
  PORTB=0b00001001;    
  MSDelay(50);  
  
  }
 
}

//millisecond delay for XTAL=8MHz, PLL=48MHz
//The HCS12 Serial Monitor is used to download and  the program.
//Serial Monitor uses PLL=48MHz

 void MSDelay(unsigned int itime)
  {
    unsigned int i; unsigned int j;
    for(i=0;i<itime;i++)
      for(j=0;j<4000;j++);    //1 msec. tested using Scope
  }