Heartrate monitor Bluetooth

// Compiler: Keil, Target Chip AT89S52 or similar 
sbit SENSOR = P3^7; //sensor is connected to this pin, can be any other pin also 
unsigned int beatms; //Calculate time between two high going pulses in ms 
float bpm; // Beats per minute calculated from beatms variable above 
/*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- 
Delay x Milisecond 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/ 
void delay_ms(unsigned int x) // delays x msec (at fosc=11.0592MHz) 
{ 
 unsigned char j=0; 
while(x-- > 0) 
 { 
 for (j=0; j<125; j++){;} 
 } 
} 
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= 
// -=-=-=-=- Main Program -=-=-=-=-=-=-= 
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= 
void main() 
{ 
// -=-=- Intialize variables -=-=-= 
beatms=0; // will store duration between two pulses 
 
// -=-=- Program Loop -=-=-= 
while(1) 
{ 
while(SENSOR==0);// wait for high pulse from sensor 
delay_ms(10); // 10ms delay so that it does not listen to any noise 
beatms = 10; // start counting beatms from 10ms since we have delay above 
 
while(SENSOR==1)// wait until signal is high 
{ 
delay_ms(1); //wait 1msec 
beatms++; //keep incrementing counter each 1ms 
} 
 
while(SENSOR==0) //keep looping till signal goes back high, wait for next 
{ 
delay_ms(1); //wait 1msec 
beatms++; //keep incrementing counter each 1ms 
} 
// beatms variable will now have time in ms between two high edge pulse 
bpm = (float)60000/beatms; // see document of #1181 for this calculation 
 
if(bpm > 200) 
{ 
// Invalid, Wait for next cycle 
} else { 
// Display reading in BPM, print variable BPM to LCD Display or Serial port. 
} 
} 
}