MBED Ticker doesn't attach interrupt

Question

I have a class:

#ifndef _BUTTON_LISTENER_H_
#define _BUTTON_LISTENER_H_

#include <iostream>
#include <vector>
#include "mbed.h"
#include "Buttons/MenuButton.h"
#include "MenuNavigator.h"

class MenuNavigator;

class ButtonListener
{
    public: 
        ButtonListener(MenuNavigator* navigator, unsigned int samplePeriod_us,
            MenuButton* select, MenuButton* down, 
            MenuButton* up, MenuButton* cancel);
        vector<MenuButton*> getButtons();
        MenuNavigator* getNavigator();
    protected:
        void init();
        void isr();
        vector<MenuButton*> buttons;
        MenuNavigator* navigator;
        unsigned int samplePeriod_us;
        Ticker ticker;
};

#endif

And its implementation:

#include "ButtonListener.h"
#include "Buttons/MenuButton.h"

ButtonListener::ButtonListener(MenuNavigator* navigator, 
    unsigned int samplePeriod, MenuButton* s, MenuButton* d, 
    MenuButton* u, MenuButton* c) : 
    navigator(navigator), 
    samplePeriod_us(samplePeriod_us)
{
    buttons.push_back(s);
    buttons.push_back(d);
    buttons.push_back(u);
    buttons.push_back(c);
    init();
}

void ButtonListener::init()
{
    ticker.attach_us(callback(this, &ButtonListener::isr), 500000);
}

void ButtonListener::isr()
{
    printf("in isr\n");
}

I'm attaching isr() method to create an interrupt so that it sends the text to the terminal window. But for some reason, it doesn't work.

If I put printf() statement before or after the init() method in the constructor, the text of printf() gets printed, but the text in the isr() doesn't.

Any help?

Answer 1

Accidentally found the solution. I have MyClass that instantiates ButtonListener . In this class, I declared ButtonListener as a pointer:

ButtonListener* blistener; .

In the constructor of the MyClass , I had ButtonListener buttonListener = new ButtonListener(args...) . After I changed it to just buttonListener = new ButtonListener(args...) things worked out.

Hope it's going to be helpful to someone else.