check for DeviceMotionEvent Javascript

Question

I am making an interactive web-app that needs to check if there is a gyroscope present on the current device. I need to do this check once before all the other javascript is loaded.

I found the following article on how to do this.

But when i try this code see below always get there is no gyroscope.. both on iphone and desktop and laptop and tablet. Why is this happening? Is there a solution to this problem or is this not possible?

See my code i have tried so far:

if (window.DeviceMotionEvent) {
    console.log("yes "+window.DeviceMotionEvent);
    gyroscope = true;
    followMouse = false;
    current_interaction_mode = 'gyroscope_option';
}else{
    console.log("no "+ window.DeviceMotionEvent);
    followMouse = true;
    gyroscope = false;
    current_interaction_mode = 'followMouse_option';
}

$(document).ready(function(){
    //all the other code to be executed...
});

if something is missing or unclear pls let me know :)
Thanks for all the help in advance.