Motion module doesn’t work on iPod touch

[Ivoah]

I’m using the latest TestFlight Pythonista beta (311016) on iOS 11.2.1.

After calling motion.start_updates() any motion.get_ function just returns (0.0, 0.0, 0.0).

[Phuket2]

@Ivoah, I am using same beta and iOS as you. I am on latest iPad Pro 12.9' The below works for me

import ui
import motion


class MyClass(ui.View):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.make_view()
        self.update_interval = 1

    def make_view(self):
        motion.start_updates()

    def will_close(self):
        motion.stop_updates()

    def update(self):
        print(motion.get_gravity()) 

if __name__ == '__main__':
    f = (0, 0, 300, 400)
    v = MyClass(frame=f)
    v.present(style='sheet', animated=False)

[omz]

I think the problem may be that the iPod touch doesn't have a magnetometer. At least that's what this StackOverflow post is suggesting, and it makes sense to me.

[dgelessus]

@omz But the accelerometer and gyroscope should still be usable, right? As I understand it, currently all the functions are returning zeros, not just the one for the magnetic field.

[omz]

@dgelessus Core Motion combines the data of different sensors. The culprit seems to be the reference frame that is used for initializing the motion manager.

[francois-baptiste]

@omz It would be nice to have this bug fixed. I especially bought an ipod touch 6 to enjoy pythonista... Until then, as little consolation we can use objc_util module to get discrete device orientation... https://github.com/njmcn/Pythonista/blob/master/facedown.py