Magnetic input for mobile virtual reality

Modern smartphones can create compelling virtual reality (VR) experiences through the use of VR enclosures, devices that encase the phone and project stereoscopic renderings through lenses into the user's eyes. Since the touch screen in such designs is typically hidden inside an enclosure, the main interaction mechanism of the device is not accessible. We present a new magnetic input mechanism for mobile VR devices which is wireless, unpowered, inexpensive, provides physical feedback, requires no calibration, and works reliably on the majority of modern smartphones. This is the main input mechanism for Google Cardboard, of which there are over one million units. We show robust gesture recognition, at an accuracy of greater than 95% across smartphones and assess the capabilities, accuracy and limitations of our technique through a user study.