Developers have found new header files in a directory labeled "compass" under iPhone OS 3.0 beta 5. These files point to Japanese company Asahi Kasei’s azimuth sensor No. AK8973. The reference describes a chip otherwise known as a digital compass, or a magnetometer, that comes bundled with a master clock oscillator.
The confirmation of this additional hardware on the next-generation iPhone is exciting, to say the least. Applications that would take advantage of an azimuth sensor have only begun to develop and make a multitude of new functionality possible.
One of the new buzzwords is "augmented reality" and this is impressive to see working in practice. Essentially, since the iPhone always knows its exact position in space, it can overlay data and graphics over live video. Think about what the Terminator might see when it looks around the room.
Objects are recognized, buildings are identified, threats to the mission are... well, you get the idea. One more realistic application would be to overlay constellations on a live view of the sky.The azimuth sensor would make turn-by-turn GPS more accurate, as well as confirm the orientation of the iPhone in three dimensions. The Android G1 has already demonstrated this functionality. By simply turning the device its possible to browse Google Street View.
The Asahi Kasei azimuth sensor is a 16-pin leadless IC package measuring 4mm square and 0.7mm thick. One of the company's specialties is manufacturing liquid submersion indicators.