We have published a tutorial and firmware which allows to put together a low-cost Attitude and Heading Reference System (AHRS) that can be used as a head-tracker for virtual acoustics. A wired version of the tracker (connected via USB), as well as a wireless version (using Bluetooth) can be realized quite simple using comercially available hardware. The tracker is based on the Arduino-compatible “9DOF Razor IMU” board by SparkFun, which contains a 3-axis gyroscope/accelerometer/magnetometer and a microcontroller to do the sensor fusion.
Open source AHRS / head-tracking using SparkFun 9DOF Razor IMU (via USB or Bluetooth) from Spatial Audio Research on Vimeo.
The next release of the SoundScape Renderer (SSR) will support the tracker.