This is a multi-part message in MIME format.

------=_NextPart_000_00BB_01C131A3.6911F7A0
Content-Type: text/plain;
        charset="iso-8859-1"
Content-Transfer-Encoding: 7bit

Hi all,
well, after my brief success with my timer I am kinda stuck again. I am
running the attached code through the MPLAB simulator, and it keeps
resetting half way through the DelayMs routine in servo.c. If I comment this
out it fails in the DelayUs routine immediately below it. I know these delay
routines are ok coz they work in different programs.

Can anybody help me out with what might be causing this behavour?

Thanks very much
regards
James Fitzsimons

------=_NextPart_000_00BB_01C131A3.6911F7A0
Content-Type: application/octet-stream;
        name="servo.c"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
        filename="servo.c"

/**********************************************************************
 *
 * Filename:    servo.c
 *
 * Description: servo-related functionality.
 *
 * Notes:       The constants in this file are specific to PIC 16F84
 *                              hardware.
 *
 * Written by James Fitzsimons for PIC hardware
 * 10/8/01
 *
 *
 **********************************************************************/

#include <pic.h>
#include "delay.h"


/**********************************************************************
 *
 * Function:    driveServo(int driveValue, unsigned char port)
 *
 * Description: Drives a hobby servo.
 *
 * Notes:       This function is specific to PIC 16F84.
 *
 * Returns:     None defined.
 *
 **********************************************************************/
void
driveServo(int driveValue, unsigned char port)
{

        int delay_remainder = 0;
        int delay_times = 0;
        int delay_amount = 0;

        delay_amount = driveValue - 1000;
        delay_times = delay_amount / 255;
        delay_remainder = delay_amount % delay_times;


        //set output port high
        port = 1;

        //delay for the pulse length
        DelayMs(1);
        do
        {
                DelayUs(driveValue);
        } while(--delay_times);
        DelayUs(delay_remainder);

        //set output port low
        port = 0;

}   /* driveServo() */

------=_NextPart_000_00BB_01C131A3.6911F7A0
Content-Type: application/octet-stream;
        name="delay.h"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: attachment;
        filename="delay.h"

/*=0A=
 *      Delay functions for HI-TECH C on the PIC=0A=
 *=0A=
 *      Functions available:=0A=
 *              DelayUs(x)      Delay specified number of microseconds=0A=
 *              DelayMs(x)      Delay specified number of milliseconds=0A=
 *=0A=
 *      Note that there are range limits: x must not exceed 255 - for xtal=0A=
 *      frequencies > 12MHz the range for DelayUs is even smaller.=0A=
 *      To use DelayUs it is only necessary to include this file; to use=0A=
 *      DelayMs you must include delay.c in your project.=0A=
 *=0A=
 */=0A=
=0A=
/*      Set the crystal frequency in the CPP predefined symbols list in=0A=
        HPDPIC, or on the PICC commmand line, e.g.=0A=
        picc -DXTAL_FREQ=3D4MHZ=0A=
        =0A=
        or=0A=
        picc -DXTAL_FREQ=3D100KHZ=0A=
        =0A=
        Note that this is the crystal frequency, the CPU clock is=0A=
        divided by 4.=0A=
=0A=
 *      MAKE SURE this code is compiled with full optimization!!!=0A=
        =0A=
 */=0A=
=0A=
#ifndef DELAY_ROUTINE       //-- Check if already loaded!!!=0A=
=0A=
#define DELAY_ROUTINE      //-- MAKE SURE CANNOT RELOAD =0A=
#ifndef XTAL_FREQ=0A=
//#error NO XTAL_FREQ DEFINED - Is Required for DelayUs!=0A=
#define XTAL_FREQ       4MHZ            /* Crystal frequency in MHz */=0A=
#endif=0A=
=0A=
#define MHZ     *1000                   /* number of kHz in a MHz */=0A=
#define KHZ     *1                      /* number of kHz in a kHz */=0A=
=0A=
#if     XTAL_FREQ >=3D 12MHZ=0A=
#define DelayUs(x)      { unsigned char _dcnt; \=0A=
                  _dcnt =3D (x)*((XTAL_FREQ)/(12MHZ)); \=0A=
                  while(--_dcnt !=3D 0) \=0A=
                          continue; }=0A=
#else=0A=
=0A=
#define DelayUs(x)      { unsigned char _dcnt; \=0A=
                  _dcnt =3D (x)/(12MHZ/(XTAL_FREQ))|1; \=0A=
                  while(--_dcnt !=3D 0) \=0A=
                          continue; }=0A=
#endif=0A=
=0A=
 extern void DelayMs(unsigned char);=0A=
#endif=0A=
=0A=
=0A=

------=_NextPart_000_00BB_01C131A3.6911F7A0
Content-Type: application/octet-stream;
        name="Delay.c"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: attachment;
        filename="Delay.c"

/*=0A=
 *      Delay functions=0A=
 *      See delay.h for details=0A=
 *=0A=
 *      Make sure this code is compiled with full optimization!!!=0A=
 */=0A=
=0A=
#include        "delay.h"=0A=
=0A=
void=0A=
DelayMs(unsigned char cnt)=0A=
{=0A=
#if     XTAL_FREQ <=3D 2MHZ=0A=
        do {=0A=
                DelayUs(996);=0A=
        } while(--cnt);=0A=
#endif=0A=
=0A=
#if    XTAL_FREQ > 2MHZ =0A=
        unsigned char   i;=0A=
        do {=0A=
                i =3D 4;=0A=
                do {=0A=
                        DelayUs(250);=0A=
                } while(--i);=0A=
        } while(--cnt);=0A=
#endif=0A=
}=0A=

------=_NextPart_000_00BB_01C131A3.6911F7A0--

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads