Magnets!

Connection to extensions to hardware that does not alter the smartphone device per se. The MagGetz approach of using magnetic components coupled with the smartphone magnetometers sounds pretty interesting. I hadn’t learned much about magnetic extensions to smartphones, but they sound like a great technical possibility, which I’ll definitely try out. Besides the advantages outlined by the authors of the MagGetx system, I thought of the following:

  • The calibration is the key procedure. This means that a system that allows for the recognition / declaration of the widgets can definitely support a whole variety of customizable inputs.
  • As the magnetic sensor does not require power or wireless connections, it would be pretty great for embedded controls. It would also be easy to embed in wearable and fabric-based projects.
  • As for DIY, magnets are somewhat cheap and easily available or re-used. If I can find ways to calibrate and gesture-recognize them, they can be great tools for quick prototyping and experimental designs.

Future readings on this topic

On the use of magnets for smartphone interaction (from MagGetz paper)

  • Ketabdar, H., Haji-Abolhassani, A., Yüksel, K.A., Kehribar, I., Ercil, A., Digital Music Performance for Mobile Devices Based on Magnetic Interaction, IEEE Transactions on Instrumentation and Measurement, (2011), vol.60, no.11, 3524-3533.

  • Harrison, C., Hudson, S. E., Abracadabra: wireless, high-precision, and unpowered finger input for very small mobile devices. In Proc. of UIST, (2009), 121-

  • Ketabdar, H., Roshandel, M., Yüksel, K.A., MagiWrite: towards touchless digit entry using 3D space around mobile devices. In Proc. of MobileHCI, (2010), 443-446.

  • Ketabdar, H., Yüksel, K., A., Roshandel, M., MagiTact: interaction with mobile devices based on compass (magnetic) sensor. In Proc. of IUI, (2010), 413-414.

  • Shirazi, A.S., Moghadam, P., Ketabdar, H., Schmidt, A., Assessing the vulnerability of magnetic gestural authentication to video-based shoulder surfing attacks. In Proc. of CHI, (2012), 2045-2048.

On malleable interfaces:

  • Villar, N., Gellersen, H., A Malleable Control Structure for Softwired User Interfaces. In Proc. of TEI, (2007), 49-56.

Unity and Android sensors, again

  • downloaded new version
  • found a super recent open source plugin that seems to be exactly what i need
  • I will test re-implementing the shellphone example with this plugin before adding the new controls
  • I just found out that my phone has no gyroscope! The horror!
  • Unity still creates an aggregate gyroscope out of the existing sensors, so I can use the vanilla Input API for that.
  • Now I’ll test if it works as some kind of interface for the magnetometer too. Ok, it seems that magnetic fields do not affect the Unity gyroscope.
  • So far, it seems I’ll need to combine the plugin and the native input system to get the most out of the Android sensors.

Sensors overview - Android docs Sensor values explanation - Android docs

Shellphone 2.0

I will now start work on the second version of the Shellphone prototype. I’ll start a new log for that.