Declare of global variable

Mbed OS
1

Please share sample code for AN EXTERNAL INTRRUPT Digital INPUT WHICH YOU USE TO COUNT THE NUMBER OF INPUT PULSES AND STORE THE COUNT IN A GLOBAL VARIABLE

Thanks

2

Hello,

#include "mbed.h"

InterruptIn button(BUTTON1); // like an external source of pulses

/* in some cases may be necessary use also keyword volatile 
for avoid compiler optimization */
volatile int counter = 0; 

void pressed(){
    counter++; 
}

int main()
{
    printf("Interrupt counter example\n");
    // fall or rise
    button.fall(callback(&pressed)); 
    //button.rise(callback(&pressed)); 
    while (true) {
        thread_sleep_for(1000);
        printf("Current counter value is %d\n",counter);
    }
}

BR, Jan