#include	<pic.h>
#include  <conio.h>
#include <ctype.h>
#include  <stdio.h>
#include  <stdlib.h>     /* must include for atoi */



#define DATA_EEMEM_PROTECT_DISABLE 0x0100
#define XT_OSC 0x0001
#define DISABLE_DEBUG 0x0800

#define CP0		0x1010
#define CP1		0x2020

/* CP0,CP1  code protect off*/
/* other bits zero which means WDT disabled
  Low Voltage prm disabled, brownout disabled
  power up timer enabled */

__CONFIG((CP1 | CP0) | DATA_EEMEM_PROTECT_DISABLE  | XT_OSC | DISABLE_DEBUG);



#define bitset(var,bitno) ((var) |= (1 << (bitno)))
#define bitclr(var,bitno) ((var) &= ~(1 << (bitno)))
#define bittst(var,bitno) (var & (1 << (bitno)))

/* use Capture mode to measure the pulse width of a switch */


/* return 8 bit char from Recieve port */
char getch ()
{
  unsigned char c;

  /* while (!RCIF) */
  while (!bittst(PIR1,5));  /* check RCIF bit */
	 
  c = RCREG;
  return(c);
}

/* send 8 bit char to Recieve port */
void putch (c)
  char c;

{
  /* wait until transmit reg empty */
  /* while (!TXIF) */
  while (!bittst(PIR1,4));  /* check RCIF bit */
  TXREG = c;
}

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


unsigned int last_capture;
unsigned int this_capture;
unsigned int delta;

unsigned char capture_flag;
unsigned char edge_type;


void interrupt
timer_isr(void)
{

  bitclr(PIR1,2);   // 	CCP1IF = 0; clear capture interrupt flag
  this_capture = CCPR1H << 8 ;
  this_capture =  this_capture | CCPR1L ;
  if (edge_type == 0) {
      last_capture = this_capture;
  } else {
    /* compute delta */
    if (this_capture > last_capture) {
      delta = this_capture - last_capture;
    } else {
      /* this is timer overflow case */
      delta = this_capture + ~last_capture + 1;
    }
  }
  capture_flag = 1;
}



main(void)
{

  unsigned char i;
  
  /* setup Async communication */
  bitclr(TXSTA, 6); /* 8-bit transmit */
  bitset(TXSTA, 5); /* transmit enable*/
  bitclr(TXSTA, 4); /* async mode */
  bitset(TXSTA, 2); /* high speed mode */


  bitset(TRISC, 7); /* serial port enable */
  bitset(TRISC, 6); /* serial port enable */
  bitset(RCSTA, 7); /* serial port enable */
  bitclr(RCSTA, 6); /* 8-bit reception */
  /* set baud rate */

  SPBRG = 95;  /* 9600 in high baud rate mode, crystal = 14.7456 Mhz */


  bitset(RCSTA, 4); /* enable recieve */


  // initialize timer 1
  // prescale by 8
  bitset(T1CON,5);  //	T1CKPS1	= 1;
  bitset(T1CON,4);  // T1CKPS0 = 1;

  bitclr(T1CON,3); // enable the oscillator T1OSCEN = 0;
  bitclr(T1CON,1); //choose internal FOSC/4 TMR1CS = 0;             
  bitset(T1CON,0); // enable oscillator   TMR1ON 	= 1;  

  /* set up capture

  /* set CCP1 input */
  bitset(TRISC,2);

  /* capture every falling edge 0100 */
  bitclr(CCP1CON, 3);
  bitset(CCP1CON, 2);
  bitclr(CCP1CON, 1);
  bitclr(CCP1CON, 0);

  // enable interrupts 
  bitclr(PIR1,2);   // 	CCP1IF = 0; clear capture interrupt flag
  bitset(PIE1, 2) ;  // enable capture interrupt CCP1IE = 1;
  bitset(INTCON,6); /* enable peripheral interrupts, PEIE */
  bitset(INTCON,7); /* enable global interrupts, GIE */

  printf("Ready for button mashing!");
  pcrlf();
  for(;;) {
    CCP1CON = 0;  /* turn off when changing modes */
    CCP1CON = 0x4; /* capture every falling edge */
    edge_type = 0; /* looking for falling edge */
    capture_flag = 0;
    while(!capture_flag);
    capture_flag = 0;
    CCP1CON = 0;  /* turn off when changing modes */
    CCP1CON = 0x5; /* capture every rising edge */
    edge_type = 1; /* looking for rising edge */
    while(!capture_flag);
    printf ("Switch pressed, timer ticks: %u",
	    delta);
    pcrlf();
  }
}

<div align="center"><br /><script type="text/javascript"><!--
google_ad_client = "pub-7293844627074885";
//468x60, Created at 07. 11. 25
google_ad_slot = "8619794253";
google_ad_width = 468;
google_ad_height = 60;
//--></script>
<script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script><br />&nbsp;</div>