File content as of revision 0:7fa8f6402b51:

#include "mbed.h"
#include "XNucleo53L0A1.h"
#include <stdio.h>

#define VL53L0_I2C_SDA   D14 
#define VL53L0_I2C_SCL   D15 

static XNucleo53L0A1 *board=NULL;

DigitalOut led1(LED1);

InterruptIn button1(USER_BUTTON);
volatile bool button1_pressed = false; // Used in the main loop
volatile bool button1_enabled = true; // Used for debouncing
Timeout button1_timeout; // Used for debouncing

// Enables button when bouncing is over
void button1_enabled_cb(void)
{
    button1_enabled = true;
}

// ISR handling button pressed event
void button1_onpressed_cb(void)
{
    if (button1_enabled) { // Disabled while the button is bouncing
        button1_enabled = false;
        button1_pressed = true; // To be read by the main loop
        button1_timeout.attach(callback(button1_enabled_cb), 0.3); // Debounce time 300 ms
    }
}

int main()
{
    
    //button1.mode(PullUp); // Activate pull-up
    button1.fall(callback(button1_onpressed_cb)); // Attach ISR to handle button press event

    int idx = 0; // Just for printf below
    int status;
   uint32_t distance;

    DevI2C *device_i2c = new DevI2C(VL53L0_I2C_SDA, VL53L0_I2C_SCL);
    
    /* creates the 53L0A1 expansion board singleton obj */
    board = XNucleo53L0A1::instance(device_i2c, A2, D8, D2);

    /* init the 53L0A1 expansion board with default values */
    status = board->init_board();
    if (status) {
        printf("Failed to init board!\r\n");
        return 0;
    }

   while (1) {
        status = board->sensor_centre->get_distance(&distance);
        if (status == VL53L0X_ERROR_NONE) {
           printf("Distance : %ld\r\n", distance);
        }
        if (button1_pressed) { // Set when button is pressed
            button1_pressed = false;
            printf("Button pressed %d\n", idx++);
            led1 = !led1;
        }
   }
}