Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
If you only have one controller, a more flexible approach would be to take the first value returned by the QGamepadManager rather than hard coding it like that. It's not guaranteed that you will have the same value each time.
Might be a silly question but what if you reset the configuration of the device ?