BMA253
Data sheet
Page 35
For each orientation mode the (0x0C) orient bits have a different meaning as shown in Table 14
to Table 16:
Table 14: Meaning of the (0x0C) orient bits in symmetrical mode
(0x0C)
orient
Name
Angle
Condition
|acc_y| < |acc_x| - ‘hyst’
and acc_x - ‘hyst’’ ≥ 0
x00
portrait upright
portrait upside down
landscape left
315° < < 45°
135° < < 225°
45° < < 135°
225° < < 315°
|acc_y| < |acc_x| - ‘hyst’
and acc_x + ‘hyst’ < 0
x01
x10
x11
|acc_y| ≥ |acc_x| + ‘hyst’
and acc_y < 0
|acc_y| ≥ |acc_x| + ‘hyst’
and acc_y ≥ 0
landscape right
Table 15: Meaning of the (0x0C) orient bits in high-asymmetrical mode
(0x0C)
orient
Name
Angle
Condition
|acc_y| < 2∙|acc_x| - ‘hyst’
and acc_x - ‘hyst’ ≥ 0
x00
x01
x10
x11
portrait upright
portrait upside down
landscape left
297° < < 63°
117° < < 243°
63° < < 117°
243° < < 297°
|acc_y| < 2∙|acc_x| - ‘hyst’
and acc_x + ‘hyst’ < 0
|acc_y| ≥ 2∙|acc_x| + ‘hyst’
and acc_y < 0
|acc_y| ≥ 2∙|acc_x| + ‘hyst’
and acc_y ≥ 0
landscape right
Table 16: Meaning of the (0x0C) orient bits in low-asymmetrical mode
(0x0C)
orient
Name
Angle
Condition
|acc_y| < 0.5∙|acc_x| - ‘hyst’
and acc_x - ‘hyst’ ≥ 0
x00
x01
x10
x11
portrait upright
portrait upside down
landscape left
333° < < 27°
153° < < 207°
27° < < 153°
207° < < 333°
|acc_y| < 0.5∙|acc_x| - ‘hyst’
and acc_x + ‘hyst’ < 0
|acc_y| ≥ 0.5∙|acc_x| + ‘hyst’
and acc_y < 0
|acc_y| ≥ 0.5∙|acc_x| + ‘hyst’
landscape right
and acc_y ≥ 0
In the preceding tables, the parameter ‘hyst’ stands for a hysteresis, which can be selected by
setting the (0x2C) orient_hyst bits. 1 LSB of (0x2C) orient_hyst always corresponds to 62.5 mg,
in any g-range (i.e. increment is independent from g-range setting). It is important to note that
by using a hysteresis ≠ 0 the actual switching angles become different from the angles given in
the tables since there is an overlap between the different orientations.
The most significant bit of the (0x0C) orient bits (which is displayed as an ´x´ in the above given
tables) contains information about the direction of the z-axis. It is set to ´0´ (´1´) if acc_z ≥ 0
(acc_z < 0).
BST-BMA253-DS000-01 | Revision 1.0 | August 2015
Bosch Sensortec
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Note: Specifications within this document are subject to change without notice.
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