File content as of revision 2:a8ab43d7fa70:

 #include "mbed.h"
 #include "LPC17xx.h"
#include "TextLCD.h"
 TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD16x2);
Serial pc (USBTX, USBRX);
PwmOut speaker(p21);
 
 Timer timer;
 DigitalOut led(LED1);
 int begin, end;
 int beats=0;
 int b=0;
 int hr=0;
 int samplerate=10;
 
 int main() {
     timer.start();
     
     while (1){
         b=timer.read();
     
     hr = (b * 60)/samplerate;
     lcd.locate(0,1);
        lcd.printf("Beats %d" ,b);
     if (hr<100) 
     {
         
         lcd.locate(0,0);
        lcd.printf("heart fine "); 
        }
        
     if (hr>=100)
     {
         lcd.cls(); 
         //lcd.locate(0,0);
        //lcd.printf("Alarm %d", hr);
        speaker.period(1.0/500.0); // 500hz period
        speaker =0.5;
        timer.reset();
     }    
         speaker=0.0; // turn off audio

     }
     
     //begin = timer.read_us();
     led = !led;
     //end = timer.read_us();
     //printf("Toggle the led takes %d us", end - begin);
 }