BMA222 Bosch Sensortec, BMA222 Datasheet - Page 31

• Manufacturer Part Number: BMA222
• Description: 3-AXIS ACCELEROMETER DIGITAL SMD
• Manufacturer: Bosch Sensortec

Specifications of BMA222

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 828-1025-2

BMA222
Bosch Sensortec
Data sheet
In the preceding tables, the parameter
‘hyst’
stands for a hysteresis, which can be selected by
setting the (0x0C) orient_hyst bits. 1 LSB of (0x0C) 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).
Figure 9 shows the typical switching conditions between the four different orientations for the
symmetrical mode (i.e. without hysteresis):
Figure 9: Typical orientation switching conditions w/o hysteresis
The orientation interrupt is enabled (disabled) by writing ´1´ (´0´) to bit (0x16) orient_en. The
interrupt is generated if the value of (0x0C) orient has changed. It is automatically cleared after
one stable period of the (0x0C) orient value. The interrupt status is stored in the (0x09)
orient_int bit.
If temporary or latched interrupt mode is used, after the generation of the interrupt the changed
(0x0C) orient value is kept fixed as long as the interrupt persists (e. g. until the latch time
expires or the interrupt is reset). After clearing the interrupt, the (0x0C) orient is only updated
with the next following value change (i.e. with the next occurring interrupt). In order to ensure
the continuous availability of up-to-date orientation data it is therefore optimal to use the non-
latched interrupt. It is strongly advised against using latched interrupt mode or temporary
interrupt mode with latch times above 50 ms for orient recognition.
Rev. 1.0
Page 31
07 March 2011
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Note: Specifications within this document are subject to change without notice.