The problems with motion sensing in the iPhone 5s
are indeed connected to hardware, suggests RealityCap CEO Eagle Jones. Jones notes that whereas previous iPhones were based on STMicroelectronics accelerometers, the 5s uses a Bosch Sensortech part. Both sensors have similar variance, but the Bosch part has higher bias, noted
to be consistent with the inaccuracies people are seeing in iPhone apps. Jones estimates an offset of +/-5 degrees, versus just +/-1 degree for the STM accelerometer.