BMA220 datasheet(24/60 Pages) BOSCH

24 / 60 page

BMA220

Data sheet

Bosch Sensortec

Rev. 1.10

Page 24

13 April 2011

as copying and passing on to third parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.

Note: Specifications within this document are subject to change without notice. Document is not intended for publication.

5.6 Orientation recognition

The orientation recognition feature informs on an orientation change of the sensor with respect

to the gravitational field vector g. The measured acceleration vector components with respect to

the gravitational field look as follows.

Figure 8: Definition of acceleration-vector components





[with respect to graviational field vector g (black dot = pin 1 identifier) ]

acc_x = 1g·sin·cos

acc_y = −1g·sin·sin

acc_z = 1g·cos

→ acc_y/acc_x = −tan

The output register is called orient and defined in the following way:

‘

0xx’ upward looking (z>0):

‘

000’ portrait upright (315°<

<45°)

→ |acc_y/acc_x|<1 && acc_x>0

‘

001’ portrait upside down (135°<

<225°)

→ |acc_y/acc_x|<1 && acc_x<0

‘

010’ landscape left (45°<

<135°)

→ |acc_y/acc_x|>1 && acc_y<0

‘

011’ landscape right (225°<

<315°)

→ |acc_y/acc_x|>1 && acc_y>0

‘

1xx’ downward looking (z<0), xx as before

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