[51] Delay between two pulses

[yogendra82]

Hi want to generate two Pulses with 1 Hz frequency but one pulse is 14 msec is high and rest 986 msec is low. Second pulse will begin just before 14 mesc of first pulse, 5 msec is high and rest 995 mesc is low.

I written a source code in Kiel compiler for AT59C52:

#include<reg52.h>  // special function register declarations  
                   // for the intended 8051 derivative       

#include<stdio.h>  // prototype declarations for I/O functions

#define PORTP1^0 
#define PORTP1^1

void Delay();     // Function prototype declaration

void main (void) 
{
    while(1)                //infinite loop 
    {
       P1^0 = 0xFF;
	   P1^1 = 0x00;
       Delay(14);
	   P1^0 = 0x00;
	   Delay (981);
	   P1^1 = 0xFF;
       Delay(5);
    }
}

void Delay()
{
    int j;
    int i;
    for(i=0;i<10;i++)
    {
        for(j=0;j<10000;j++)
        {
        }
    }
}

that code is not working. compiler shows syntax error.

please modify to this code for fullfill to above mention purpose.

 

[FvM]

Do you want us to guess what the syntax error is? Cool.

 

[xenos]

Definitely wrong:

#define PORTP1^0 
#define PORTP1^1

What is your intension on writing something like that:

P1^1 = 0xFF;

 

[bigdogguru]

Firstly, what compiler toolsuite are you using?

Besides the meaningless #define's mentioned by xenos, one issue is your delay() routine and its associated prototype are incorrectly defined.

You are passing presumably a msec value to the Delay() routine, however the routine and the prototype are defined to accept no parameters:

#include<reg52.h>  // special function register declarations  
                   // for the intended 8051 derivative       

#include<stdio.h>  // prototype declarations for I/O functions

#define PORTP1^0 
#define PORTP1^1

[COLOR="#FF0000"]void Delay();[/COLOR]     // Function prototype declaration

void main (void) 
{
    while(1)                //infinite loop 
    {
       P1^0 = 0xFF;
	   P1^1 = 0x00;
       Delay([COLOR="#FF0000"]14[/COLOR]);
	   P1^0 = 0x00;
	   Delay ([COLOR="#FF0000"]981[/COLOR]);
	   P1^1 = 0xFF;
       Delay([COLOR="#FF0000"]5[/COLOR]);
    }
}

[COLOR="#FF0000"]void Delay()[/COLOR]
{
    int j;
    int i;
    for(i=0;i<10;i++)
    {
        for(j=0;j<10000;j++)
        {
        }
    }
}

Also, if you are utilizing an AT89C52, include the AT89X52.H header, if available.

Utilizing a timer interrupt and ISR is certainly a preferable method over utilizing software delays to generate two different pulse trains.

The use of software delays where accurate time is concerned is plagued with possible problems.

BigDog