File content as of revision 4:86fd8725e198:

#include "mbed.h"

// Labs 2: Example program for using an interrupt (or callback)
// -----------------------------------------------------------
// A callback function (corresponding to an ISR) is called when a button 
//    is pressed
// The callback uses a shared variable to signal another thread

InterruptIn button(PTD0);
InterruptIn button2(PTD5);
DigitalOut led(LED_RED);
DigitalOut led2(LED_BLUE);

volatile int pressEvent = 0 ;
volatile int pressEvent2 = 0 ;
volatile int x;
volatile int z;
// This function is invoked when then interrupt occurs
//   Signal that the button has been pressed
//   Note: bounce may occur 
void buttonCallback(){
    pressEvent = 1 ;
}
void button2Callback(){
    pressEvent2 = 1 ;
}
/*  ---- Main function (default thread) ----
    Note that if this thread completes, nothing else works
 */
int main() {
    button.mode(PullUp);             // Ensure button i/p has pull up
    button.fall(&buttonCallback) ;   // Attach function to falling edge

    button2.mode(PullUp);             // Ensure button i/p has pull up
    button2.fall(&button2Callback) ;   // Attach function to falling edge
    while(true) {
        // Toggle the LED every time the button is pressed
        if (pressEvent) {
           
           x=!x;
           if (x==1){
           //led=!led;
           }
            pressEvent = 0 ; // Clear the event variable
        }
        if (x==0){
        led = !led;}
        // led2 = !led2 ;
        if (pressEvent2) {
           z=!z;
           if (z==1){
           //led2=!led2;
           }
            pressEvent2 = 0 ; // Clear the event variable
        }
        if (z==0){
        led2 = !led2;}
        Thread::wait(500) ;
    }
}