AN3182 Datasheet, PDF (1/18 Pages) STMicroelectronics – This application note describes the methods and techniques for measuring

AN3182
Application note
Tilt measurement using a low-g 3-axis accelerometer
Introduction
This application note describes the methods and techniques for measuring tilt angles from a
low-g 3-axis accelerometer. The LIS331DLH 3-axis digital accelerometer is used as an
example in this document. Other 3-axis analog or digital accelerometers may also be
applied to the tilt angle measurement procedures described here, depending on their
respective specifications.
The ultra-low power LIS331DLH digital accelerometer is housed in a 3 x 3 x 1 mm LGA-16
package. It has an I²C / SPI digital serial interface for 3-axis acceleration outputs, so no
external ADC chip is required. It also features a dynamically user-selectable full-scale
measurement range of ±2 g / ±4 g / ±8 g, with output data rates from 0.5 Hz to 1 kHz.
Section 1 of this application note introduces the terminology and parameters related to the
accelerometer, while Section 2 presents the accelerometer calibration techniques. Section 3
describes the tilt sensing theory and the methods of determining tilt angle measurement.
April 2010
Doc ID 17289 Rev 1
1/18
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