Datasheet

Data Sheet
BMA456
Page 42
BST-BMA456-DS000-01 | Version 1.1 | October 2017 Bosch Sensortec
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Note: Specifications within this document are subject to change without notice.
No Motion Detection:
The interrupt engine can also be configured as a No-motion interrupt, when register
FEATURES_IN.any_motion.settings_1.nomotion_sel is set.
No-motion is generated when the slope on all selected axis remains smaller than a programmable
FEATURES_IN.any_motion.settings_1.threshold for a programmable time. The signals and timings
relevant to the no-motion interrupt functionality are depicted in the figure below.
Register FEATURES_IN.any_motion.settings_2.duration defines the number of consecutive slope
data points of the selected axis which must exceed the threshold for an interrupt to be asserted.
Configuration settings:
1. FEATURES_IN.any_motion.settings_2.duration – the number of consecutive data points for
which the threshold condition must be respected, for interrupt assertion.
2. FEATURES_IN.any_motion.settings_1.threshold – the slope threshold.
3. FEATURES_IN.any_motion.settings_2.en_x – indicates if this feature is enabled for x axis
4. FEATURES_IN.any_motion.settings_2.en_y – indicates if this feature is enabled for y axis
5. FEATURES_IN.any_motion.settings_2.en_z –indicates if this feature is enabled for z axis
6. FEATURES_IN.any_motion.settings_1.nomotion_sel – indicates if No-motion (1) or Any-
motion (0) is selected.
acceleration
slo_no_mot_th
-slo_no_mot_th
slope
time
axis x, y, or z
axis x, y, or z
slo_no_mot_dur
timer
INT
slope(t
0
+Δt)= acc(t
0
+Δt) - acc(t
0
)
acc(t
0
+Δt)
acc(t
0
)
Figure 1 Signal timings No-motion interrupt