Speed Calculation using 8051 uC

[talal]

Hello everybody, 

I am trying to measure the speed of a machine using IR sensor interfaced with the 8051 microcontroller. I am using proteus for simulation. While running the simulation, when I provide external interrupt using push button, the value displayed on LCD is in thousands while I am only using a counter to increment once for each external interrupt so that I can know the distance through number of interrutions and divede it with time(using a timer for this purpose) to calculate the speed. I don't seem to understand the problem. It is probably due to the reason that external interrupt duration should be only for a few microseconds !! 

Need your help on this. Here is the code:

 

 

 

#include <reg51.h>

#include <stdio.h>

 

 sfr  output= 0x90;

 sbit RS= P2^0;

 sbit RW= P2^1;

 sbit EN= P2^2;   

 sbit test= P1^7;

 

 int timer;

 int counter;

 void InitializeLCD(void);

 void datadisplay(unsigned char value);

 void command(unsigned char num);

 void ready(void);

 void delay(void);

 

 

void func_ext_intr() interrupt 2{

counter = counter + 1;

}

 

 

void timer0(void) interrupt 1{

  TF0 = 0;

  TH0 = 0x00;

  TL0 = 0x00;

  TR0 = 1;

  timer = timer + 1;

  if (timer == 420){

  timer = 0;

  }

  }

 

 

 

 

//////////////////////////////Main Routine////////////////////////////////

 

 int main(void)

  {

   int i=0;

   unsigned int count=0;

   unsigned int speed=0;

   unsigned int test;

   

   char onscreen[]="SPEED";

   char value[6];

   IE = 0x8E;   

 

 ////////////////////////////STARTING TIMER///////////////////////////////

 

    TMOD = 0x21; // setting timer 1 for serial communication and timer 0 for time

    TH0 = 0x00;  

    TL0 = 0x00;

    TR0 = 1;   

 

 

   InitializeLCD();

   

   

   for(i=0;onscreen!='';i++ )

 {

  datadisplay(onscreen);

 }

 

   

   while(1)

{

 

 

for(i=5;i>=0;i–)

   {

    value=(timer%10)+0x30;

    timer= timer/10;

   }

command(0x86);

 

       for(i=0;i<6;i++)

         {

    datadisplay(value);

 

   }

command(0x8D);

 

//////////////////////////////for 2nd row////////////////////////

 

command(0xC0);

command(0xC6);

 

for(i=5;i>=0;i–)

   {

    value=(counter%10)+0x30;

    counter=counter/10;

   }

 

     command(0xC6);

     for(i=0;i<6;i++)

        {

    datadisplay(value);

 }

 

command(0xCD);

 

speed = (counter)/(timer);

 

 

///////////////////////////for third row////////////////////

 

command(0x90);

command(0x96);

 

for(i=5;i>=0;i–)

   {

    value=(speed%10)+0x30;

    speed=speed/10;

   }

 

     for(i=0;i<6;i++)

        {

    datadisplay(value);

 }

   }

 

    return 0;

  }

///////////////////////////LCD initializing Routine//////////////////////

 

 void InitializeLCD(void)

  {

   command(0x38);

   command(0x01);

   command(0x80);

   command(0x0F);

   command(0x06);

   

  } 

 

/////////////////////////LCD Interfacing Routines/////////////////////////

 

 void command( unsigned char num )

  {

   ready();

   output= num;

   RS=0;

   RW=0;

   EN=1;

   delay();

   EN=0;

   return;

  }

 

 void datadisplay(unsigned char value)

  {

   ready();

   output= value;

   RS=1;

   RW=0;

   EN=1;

   delay();

   EN=0;

   return;

  } 

 

 void ready(void)

  {

   test=1;

   RS=0;

   RW=1;

   while(test==1)

{

EN=0;

delay();

EN=1;

}

return;

  }

    

   void delay(void)

  {

    unsigned int i,j;

for(i=0;i<=8;i++)

{

for(j=0;j<=1275;j++);

}

return;

  }

 

 

[Ramkrishna]

Bro can you give me detail about the ckt diagram of this project? I’m making this project and i need your help.

[Ashutosh Bhatt]

provide some delay in your interrupt subroutine. delay of around 100-200 ms.

[Ramkrishna]

#A.M. Bhatt

Hello sir, can you please help me in this project, i do not get the circuit diagram through this code. Can you give me some detail about the ckt diagram according to this code. I’ll be thankful to you. It is my major project and i’ve no idea how will i complete. My Email id is [email protected].

[Ashutosh Bhatt]

sorry i dont have circuit. search for circuit diagram on this site or on google

[Author]

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