You have to not only obtain your service, but also register your event listener.
See for example the following section from the ApiDemos project of the (legacy) SDK Samples:
mSensorManager.registerListener(mGraphView,
SensorManager.SENSOR_ACCELEROMETER |
SensorManager.SENSOR_MAGNETIC_FIELD |
SensorManager.SENSOR_ORIENTATION,
SensorManager.SENSOR_DELAY_FASTEST);
In your case it is your MyInput class itself which implements the event listener, so you would pass your instance of that instead.