N900 accelerometer

Revision as of 13:46, 6 January 2010

The accelerometer in the phone is a LIS302DL.

It features:

  • Low power consumption
  • Dynamically selectable 2/8G fullscale.
  • Programmable multiple interrupt generator
    • Click and double click recognition
    • Zero G detection

The click and double click functionality are not implemented in the current software.

The absolute resolution is poor - 18mg (at 2g sensitivity) typical. This is fine for detecting the orientation of the phone, but makes most uses that would attempt to integrate the accelleration for detection of position useless.

For example - with a 9mg error - there is an accelleration error of 9 centimeters per meter per second.

This means that after 10 seconds, the velocity may be anywhere within a 1.8m/s (around 4MPH) band, and the position inaccurate by 4.5m. After 100s, the position inaccuracy is up to 450m. (this assumes the orientation of the phone is known exactly)

Retrieved from "http://wiki.maemo.org/N900_accelerometer"