f_10_6_root.c

* Use 10 MHz crystal frequency. * Use Timer0 for ten millisecond looptime. * Blink "Alive" LED e

#include "delay.h"

// In Hyperterminal, use File->Properties->Settings->AscII setup
// and ensure that line delay and character delay are 0 milliseconds


#include "config.h"

#include "math.h"  // for sqrt function

#include "serial.c"

/* 

This program reads decimal number, computes the 
floating point square root, and prints it out.

*/
char getch (void);
void putch (char c);
void pcrlf (void);
char getche (void);

void pcrlf (void)
{
  putch(0x0a);  putch(0x0d);
}



void putch (char c)
{
  /* wait until transmit reg empty */
  while (!TXIF);
  TXREG = c;
}

// use -lf option when compiling this program

char getch (void){
 // check RCIF bit
 while (!RCIF);
 return(RCREG);
}

// needed by scanf library call,
// get character and echo
char getche (void){
  char c;
  c = getch();
  putch(c);
  return(c);
}

#if defined(__18CXX)
void my_gets (char *s);
//return a string from the console
void my_gets (char *s){
 char c;
 
 do {
  c = getche();
  *s = c;
  s++;
  } while (c != '\r');
}
#endif


unsigned int ivalue, root;
float temp_fp, root_fp;

void main(void){
  // 19200 in HSPLL mode, crystal = 7.3728 MHz 
  serial_init(95,1); 
  printf("No buffering.");  pcrlf();
  printf("Hit any key to start..."); pcrlf();
  getch();
  while(1) {
#if defined(HI_TECH_C)
    // read integer for input using scanf 
    scanf("%d",&ivalue); 
#endif
#if defined(__18CXX)
    {// MCC18 does not have scanf, just get string from console, use atoi
	  char buf[30];
	  my_gets(buf);  // get a string from console
	  ivalue = atoi(buf);  // convert string to integer
	}
#endif
    // convert integer to floating point value
    temp_fp = ivalue; 
    // use library routine to compute floating point square root
    root_fp = sqrt(temp_fp);
    //convert to nearest integer as demo compiler does not support
    // floats in printf() statements.
    root = (unsigned int)root_fp;  
    printf("Square root of %d is: %d ",ivalue,root); pcrlf();
    DelayMs(5); // tuneable delay for USART overrun
  }
}