2D Input for Virtual Reality Enclosures with Magnetic Field Sensing

Virtual Reality enclosures are inexpensive devices that create a virtual reality experience using a mobile phone. For example, Google Cardboard lets a user put their phone inside the device and is made from cardboard, some simple lens and a magnet. Because the phone is encased, there is no way to interact with the touch screen. Cardboard uses its magnet, the phone's magnetometer and an algorithm to create a binary input [10]. In this paper, we extend the capabilities of these devices to provide continuous 2D input. In particular, we use magnetic field sensing to track the magnet in 2D on the side of the enclosure. We provide background on magnetic field sensing and show how it can apply to a VR enclosure. We examine several parameters that impact calculating the magnet's position and we focus on the challenge of dealing with the ambient geomagnetic field. Finally, we present a solution which uses the phone's inertial sensors and some user interactions that take advantage of 2D input with the magnet.