BMA250 Bosch Sensortec, BMA250 Datasheet - Page 30

• Manufacturer Part Number: BMA250
• Description: 3-AXIS ACCELEROMETER DIGITAL I/F
• Manufacturer: Bosch Sensortec
• Series: -r

Specifications of BMA250

• Featured Product: BMA250 - Digital, Triaxial Acceleration Sensor
• Axis: X, Y, Z
• Acceleration Range: ±2g, 4g, 8g, 16g
• Sensitivity: 256LSB/g, 128LSB/g, 64LSB/g, 16LSB/g
• Voltage - Supply: 1.62 V ~ 3.6 V
• Output Type: I²C™, SPI™
• Bandwidth: 8Hz ~ 1kHz
• Interface: I²C, SPI
• Mounting Type: Surface Mount
• Package / Case: 12-VQFN
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With: 828-1024 - BMA250 DAUGHTERCARD FOR DEV KIT
• Other names: 828-1023-2

Depending on the magnitudes of the acceleration vectors the orientation of the device in the
space is determined and stored in the three (0x0C) orient bits. These bits may not be reset in
the sleep phase of low-power mode. There are three orientation calculation modes with different
thresholds for switching between different orientations: symmetrical, high-asymmetrical, and
low-asymmetrical. The mode is selected by setting the (0x2C) orient_mode bits as given in table
17.
For each orientation mode the (0x0C) orient bits have a different meaning as shown in table 18
to table 20:
Rev. 1.0
© Bosch Sensortec GmbH reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
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.
Table 18: Meaning of the (0x0C) orient bits in symmetrical mode
Table 19: Meaning of the (0x0C) orient bits in high-asymmetrical mode
(0x0C)
(0x0C)
orient
orient
x00
x01
x10
x11
x00
x01
x10
x11
portrait upside down
portrait upside down
landscape right
landscape right
portrait upright
portrait upright
landscape left
landscape left
orient_mode
Name
Name
(0x2C)
Table 17: Orientation mode settings
00b
01b
10b
11b
Page 30 / not for publishing
Data sheet
135° <  < 225°
225° <  < 315°
117° <  < 243°
243° <  < 297°
BMA250
315° <  < 45°
45° <  < 135°
297° <  < 63°
63° <  < 117°
Angle
Angle
Orientation Mode
high-asymmetrical
low-asymmetrical
symmetrical
symmetrical
|acc_y| ≥ 2·|acc_x| +
|acc_y| ≥ 2·|acc_x| +
|acc_y| < 2·|acc_x| -
|acc_y| < 2·|acc_x| -
|acc_y| ≥ |acc_x| +
|acc_y| ≥ |acc_x| +
|acc_y| < |acc_x| -
|acc_y| < |acc_x| -
and acc_x -
and acc_x +
and acc_x +
and acc_x -
and acc_y < 0
and acc_y ≥ 0
and acc_y < 0
and acc_y ≥ 0
Condition
Condition
‘hyst’’
‘hyst’
‘hyst’
‘hyst’
Bosch Sensortec
03 March 2011
‘hyst’
‘hyst’
‘hyst’
‘hyst’
≥ 0
≥ 0
< 0
< 0
‘hyst’
‘hyst’
‘hyst’
‘hyst’