How to generat counter-INT in the RTX-Tiny?

Your message is unclear. What is INT in your context? Can you describe your problem with a program example?

Your message is unclear. What is INT in your context? Can you describe your problem with a program example?

Hi Reinhard,

I explain better. Excuse my bad English OK.

I'm using the RTX-Tiny, making the project a speedmeter and odometer for the final university project.
In calculating the distance using a wheel of 2 meters long, I am using a sensor for a resolution of 2 pulses / meter.

For resolution of the 100 meters, 2 pulses/meter * 100 meters = 200 pulses.

Timer1 set up as the counter for counter of pulses by external border, with auto-reload of 8 bits. The T/C1, count 200 pulses at that time it generates an interruption (INT1) for 8051, get an increment for the variable and return to the swith tasks.

The 8051 is losing interruptions, and can not count the number of interruptions in the correct time, example:
90 km/h = 1.5 km/minute = 25 meters/second
(25 meters/second)* 2 pulses/meter = 50 pulses/second = 50 Hz.

To go 100 meters at 90 km/h, spends 4 seconds, and genereting 50 pulses/second * 4 second = 200 pulses = 1 interrupt = 100 meters.

The number of pulses at 1 minute = 50 * 60 = 3000 pulses = 3000 / 200 = 15 interrupts

But, generating with signal generator at pin P3^5 of the 8051, signal of the 50 Hz for 4 seconds, the RTX-Tiny don't count 1 interrupt. And generating 50 Hz for interval of 1 minute, have count 14 interrupts!!!

The time-ticks for RTX is default.

Bellow the software

The result for count interrupt for T/C1 is being placed on the port P2.
The LED2 blinking for the work the OS.

#include <REG52.h>
#include <rtx51tny.h>
#include <stdio.h>

//***** DEFINES DAS TASKS
#define INICIO 0
#define PISCA 1

// define pinos
sbit LED2 = P1^7;

#define Porta_contagem P2

static conta_int = 0x00;

#define MAX_CONT1 255
#define PULSOS 200

sbit VEL_IN = P3^5;

// **** Start Program

static void trata_timer2 (void) interrupt 3 using 2
{

conta_int++; P2 = conta_int;

}

void init (void) _task_ INICIO
{

unsigned int pulsos = (MAX_CONT1 - PULSOS);

VEL_IN=1;

TR1=TF1=0;

EA=1;

ES = 0;

ET1 = 1;

EX1 = 0;

ET0 = 1;

EX0 = 0; TMOD = (TMOD&0xFF)|0x60;

TCON=0x10;

TH1 = TL1 = pulsos;

while (1)

{

P0=P1=P2=P3=0XFF;

P2 = 0X00;

TR1 = 1;

os_create_task ( PISCA );

os_delete_task ( INICIO );

}

}

void pisca (void) _task_ PISCA

{

while (1)

{

LED2 = ~LED2; os_wait (K_TMO,5000,0);

}

}

I using xtal of the 24MHz for de clock AT89s52.

In others tests, the interrupt occur beging 5 seconds, for counter 200 pulses or 1 pulse in the timer1 for overflow...?

Thanks