Call a function every x seconds until button pressed

Hey there guys, maybe it´s a simple task but it´s driving me a little bit crazy, especially QTime.
I´m learning minute by minute but sometimes I just need to ask something as I really need help.

What I would like to do is:
1- Press START button and every ´x´ seconds the MAIN FUNCTION is called, exactly like I would do in a for cycle and it must stop when I click STOP.
2- Press STOP button and I exit the loop;

Right now I have this:

Code:

---

void MainWindow::on_pushButton_START_clicked()
{
    ... here is the button that I want to use to START the loop of the main function. Every ´x´ seconds MAIN FUNCTION loops.     
}
 
void MainWindow::on_pushButton_STOP_clicked()
{
    ... here is the button that I want to use to STOP the loop of the main function...
}
 
void MainWindow::on_pushButton_MAIN_FUNCTION_clicked()
{
    ... here is the function I want to loop...
}

---

QTimer
For 1. call QTimer::start()
For 2. call QTimer::stop()
connect the slot or signal you want to call periodically to QTimer::timeout() signal.

Thank you so much! The start function is working!

But how do I use the timer->stop() inside the STOP function in order to stop the timer that was created inside the START function ?

Code:

---

void MainWindow::on_pushButton_START_clicked()
{
 
    QTimer *timer = new QTimer(this);
 
    connect(timer, SIGNAL(timeout()), this, SLOT(on_pushButton_MAIN_FUNCTION_clicked()));
    timer->start(1000);
 
}
 
void MainWindow::on_pushButton_STOP_clicked()
{
 
    ...
 
}
 
 
void MainWindow::on_pushButton_MAIN_FUNCTION_clicked()
{
    ... here is the function I want to loop...
}

---

Keep the "timer" as member of MainWindow class.