File content as of revision 0:48f4880c730b:

#include "mbed.h"
#include "PinDetect.h"
#include "TextLCD.h"
// must import Cookbook PinDetct library into project
// URL: http://mbed.org/users/AjK/libraries/PinDetect/lkyxpw
 
DigitalOut myled(LED1);
DigitalOut myled2(LED2);
DigitalOut myled3(LED3);
DigitalOut myled4(LED4);
Timer t;
TextLCD lcd(p36, p34, p9, p10, p15, p16); // rs, e, d0-d3
 
PinDetect pb1(p18);
PinDetect pb2(p19);
// SPST Pushbutton debounced count demo using interrupts and callback
// no external PullUp resistor needed
// Pushbutton from P8 to GND.
// Second Pushbutton from P7 to GND.
// A pb hit generates an interrupt and activates the callback function
// after the switch is debounced
 
// Global count variable
int volatile count=0;
int volatile resetcnt=0;
 
// Callback routine is interrupt activated by a debounced pb1 hit
void pb1_hit_callback (void) {
    count++;
    myled4 = count & 0x01;
    myled3 = (count & 0x02)>>1;
    myled2 = (count & 0x04)>>2;
    t.start();
    if (resetcnt==1) {
        t.reset();
        resetcnt=0;
       } 
}
// Callback routine is interrupt activated by a debounced pb2 hit
void pb2_hit_callback (void) {
    count--;
    myled4 = count & 0x01;
    myled3 = (count & 0x02)>>1;
    myled2 = (count & 0x04)>>2;
    t.stop();
    resetcnt=resetcnt++;
}
int main() {
 
    // Use internal pullups for pushbutton
    //pb1.mode(PullUp);    
    //pb2.mode(PullUp);
    // Delay for initial pullup to take effect
    //wait(.01);
    // Setup Interrupt callback functions for a pb hit
    pb1.attach_deasserted(&pb1_hit_callback);
    pb2.attach_deasserted(&pb2_hit_callback);
    // Start sampling pb inputs using interrupts
    pb1.setSampleFrequency();
    pb2.setSampleFrequency();
    //Blink myled in main routine forever while responding to pb changes
    // via interrupts that activate the callback counter function
    while (1) {
        myled = !myled;
        
                lcd.printf("Timer\n");
                lcd.printf(" %4.2f sec\n", t.read());
                
                
        wait(.01);
        lcd.cls();
        resetcnt=1;
        
    }
 
}