As far as I know about hardware, the accelerometer chip is the Bosch
Sensortec's 3-axis BMA150 and the digital compass is Asahi Kasei's
AK8973 (similar to iPhone). I am not sure about the accuracy of each
sensor but the digital compass seems to function fairly well in the
Here's the spec and brochure.
Additional digital filtering is possible to improve S/N ratio (down to 25Hz bandwidth). Typical noise level and quantization lead to a resolution of 4mg.
Gulf Coast Data Concepts, LLC sells USB Accelerometer.
It seems that HTC G1 phone has accelerometer AK8976A. According to this post, it's
That said, it might not actually deliver that kind of performance, as I came across some posts on Android dev forums about the sensor in the G1 (AKM AK8976A - 3-axis accelerometer + digital compass) being very inconsistent, with sampling rates varying from 5-125 Hz and a high degree of error, thus requiring additional processing in apps (Kalman filters, etc.) to clean up the input data.
Which is much worse than iPhone's BMA-150 :( I'm using Sensor Insider Pro app to monitor the accelerometer, and it seems to be very noisy. The sampling rate is ~ 20ms.