Heart Beat Rate Meter

I'm planning to design a Heart rate meter.. Need an idea to start with
Is the following logic correct?

1.Start the timer and count for 20seconds
2.check for pulses from input port
3.for each pulse; increment a variable
4.when t=20seconds;stop timer
5.multiply the current value of assigned variable by 3(to get value for 60seconds\per min)
6.display the obtained result value

Need some idea about using the Timer in 8051..
Ajay, Majoka please guide...

as we always say, generate a smaller tick e.g. 50ms with a 12Mhz crystal using timer, keep a counter that counts for how much time you want the delay.

say if its 1sec, then counter will go upto 20 (20x50 = 1000ms)
if 20sec counter will go upto 400 (400 x 50 = 20000ms)

got it? try it once.

nice... where you want to use this buddy?

Hehe really nice project. I was trying to make such metter too, but coudnt get nice clear discrete signal of heart beat.

C code for Heart Rate Meter:

//******************************************************//
8051 Based Heart Rate Meter Main Program
//*****************************************************//

#include <reg51.h>
  // using ride 6.1.6 IDE ,Keil also use
#include <lcd.h>

sbit gg =P1^2;


// unsigned char bt=0,sec=0,sec100=0,min=0,r,t1,t2;

// unsigned char val[] = {’0′,’1′,’2′,’3′,’4′,’5′,’6′,’7′,’8′,’9′};

void extrint (void) interrupt 0
{
bt++;

}
void timer0 (void) interrupt 1 using 1
{
TH0 = 0xdc;
sec100++;
if(sec100>
=10)
{
sec++;
sec100=0;
if(sec>
=6)
{
min++;
sec=0;
}
}
}

void disp(unsigned char n)
{
LCD_putc(val[n/100]);
LCD_putc(val[(n/10)%10]);
LCD_putc(val[n%10]);
}

void main()
{
EA = 1;
TMOD = 0×02;
IT0 = 1;
EX0 = 1;
ET0 = 1;
TR0 = 1;

LCD_delay(100);
LCD_init();
LCD_delay(100);
LCD_row1();
LCD_delay(100);
LCD_puts(”Welcome to H.R.M. “);
LCD_delay(100);
t1=0;t2=0;

while(1)
{

if(min>
=1)
{
LCD_command(0xc0);
LCD_delay(100);
LCD_putc((bt/100)+48);
r=bt%100;
LCD_putc((r/10)+48);
LCD_putc((r%10)+48);
LCD_delay(100);
bt=0;
min=0;
}
}
}
/ /***********************************************//
LCD Header File Routines
//************************************************//

#include<string.h>

#include<stdio.h>

#define LCD_clear() LCD_command(0×1) /* Clear display LCD */
#define LCD_origin() LCD_command(0×2) /* Set to origin LCD */
#define LCD_row1() LCD_command(0×80) /* Begin at Line 1 */
#define LCD_row2() LCD_command(0xC0)

sbit rs = P2^5;
sbit en = P2^6;

void lcd_en ()
{
en = 1; en = 1; en = 1;
en = 0; en = 0;
}
void LCD_delay(unsigned char ms)
{
unsigned char n;
unsigned int i;
for (n=0; n
{
for (i=0; i<1535; i++); /* For 1 ms */
}

}

void LCD_command(unsigned char command)
{
rs=0; rs = 0;
P0 = command;
lcd_en ();
LCD_delay(1);

}

void LCD_init()
{
LCD_command(0×38);
LCD_command(0×06);
LCD_command(0×0c);
LCD_command(0×01);
LCD_delay(256);
}

void LCD_putc(unsigned char ascii)
{
rs=1;
P0 = ascii;
lcd_en ();
LCD_delay(2);
LCD_command(0×0C);
}

void LCD_puts(unsigned char *lcd_string)
{
while (*lcd_string)
{
LCD_putc(*lcd_string++);
}
}

see this link and attached PDF...

Heart Beat Meter using 8051

coolmirza143 thanks for sharing this

Thanks for sharing Mirza
Here is some pictures of Heart Beat sensor PCB with the above circuit

My friends you all are welcome

Enjoy measuring your beats...

@Kartikdm nice pics but low resolution try sharing these in high quality with PCB layout file and your code after making your own design....

sorry for the resolution..Those pics are taken from my mobile camera
will publish the code after trying...