Compass¶

# ... imports
Hardware = autoclass('org.renpy.android.Hardware')

class CompassApp(App):

    needle_angle = NumericProperty(0)

    def build(self):
        self._anim = None
        Hardware.magneticFieldSensorEnable(True)
        Clock.schedule_interval(self.update_compass, 1 / 10.)

    def update_compass(self, *args):
        # read the magnetic sensor from the Hardware class
        (x, y, z) = Hardware.magneticFieldSensorReading()

        # calculate the angle
        needle_angle = Vector(x , y).angle((0, 1)) + 90.

        # animate the needle
        if self._anim:
            self._anim.stop(self)
        self._anim = Animation(needle_angle=needle_angle, d=.2, t='out_quad')
        self._anim.start(self)

    def on_pause(self):
        # when you are going on pause, don't forget to stop the sensor
        Hardware.magneticFieldSensorEnable(False)
        return True

    def on_resume(self):
        # reactivate the sensor when you are back to the app
        Hardware.magneticFieldSensorEnable(True)

if __name__ == '__main__':
    CompassApp().run()