How to use time0 as event counter on AT89S52 ?

[bianchi77]

Guys,

How can I use timer0 on AT89S52 as event counter ?
Is it related with interrupt ?

I have made some configuration but it doesn't work yet ?
Is my input voltage too low ?
I got 1.7V for high level on it...

Any ideas will be appreaciated,

Thanks a lot

 

[tpetar]

Maybe to start with reading of this :

Part 4: Interrupts, timers and counters
**broken link removed**


Best regards,
Peter

 

[errakeshpillai]

A few counter examples from ATMEL's website will help you.

 

[vinothksr08]

Guys,

How can I use timer0 on AT89S52 as event counter ?
Is it related with interrupt ?

I have made some configuration but it doesn't work yet ?
Is my input voltage too low ?
I got 1.7V for high level on it...

Any ideas will be appreaciated,

Thanks a lot

hai there,

I uploaded your code with correction with proteus design, check with that

thank you,

 

[bianchi77]

A few counter examples from ATMEL's website will help you.

Thanks for very usefull information......

 

[bianchi77]

I did :

sbit counter_input=P3^4;	 //input pulse from op-amp

void init_timer()
{
	TL0=0x00;
	counter_input = 1; //set it as input to read a pulse from op-amp
	counter_input = 0x00; //clear the counter
	TMOD=0x05;
	P0=0x00;
}

void main() //main program

{ 
unsigned char serial_char;

unsigned int counter=0,d1,d2,d3,dx,dy,dz,x;
  lcd_ini(); //init LCD
  init_timer();//init timer0
  TR0=1;
   while (1)
    {
		counter=TL0;
		P0=TL0;
		x=counter/10;
		d1=counter%10;
		d2=x%10;
		d3=x/10;
		
		dx=d1+48;
		dy=d2+48;
		dz=d3+48;
		lcd_data(dx); lcd_data(dy); lcd_data(dz);
	}

It's displaying a value alredy on LCD, but it's not synchronized with the input P3.4, do I missing something here ?
I want to display per second and then per minute ? Do I need interrupt for it ? how to use it ?

Thanks

 

[bianchi77]

update :
Guys,

I'm trying to count a pulse from T0 input on P3.4,

Here's the code :
sbit counter_input=P3^4; //input pulse from op-amp

 void init_timer()
{
   TL0=0x00;
   //TH0=0x00;

   counter_input = 1; //set it as input to read a pulse from op-amp
   counter_input = 0x00; //clear the counter
   
   TMOD=0x05;
   P0=0x00;
}
main :
.
.
.
unsigned int counter=0,d1,d2,d3,dx,dy,dz,x;
  lcd_ini(); //init LCD
  init_timer();//init timer0
  TR0=1;
 
   while (1)
    {
      counter=TL0;
      P0=TL0;
      x=counter/10;
      d1=counter%10;
      d2=x%10;
      d3=x/10;
      
      dx=d1+48;
      dy=d2+48;
      dz=d3+48;
   lcd_data(dx); lcd_data(dy);     lcd_data(dz);   

}

I got the output already, but it's not consistent yet,
781, 881,321, 050...etc,
I tested with putting input to the sensor it's responding on the display according to the input, but...it's not yet displaying for example 000, 030, 050,090, etc...

Any ideas on this case ?
I'm abit confuse on using timer and counter ....

Thanks for the ideas