Specifications

BMA180
Preliminary data sheet
Bosch Sensortec
Rev. 1.0 Page 40 / - proprietary information - 06 March 2009
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Specifications within this document are preliminary and subject to change without notice. Document is not intended for publication.
If latch_INT=0, the interrupt is not a latched interrupt (as in figure 6) and then it is reset as soon
as High_thresh criteria becomes false. When an interrupt occurs, the interrupt counter is reset.
7.9.6 Slope interrupt (any motion interrupt)
7.9.6.1 General explanation
BMA180 is providing a possibility to detect slope/any motion events of a device (e. g. tumbling).
Functionality is basically as follows (see figure below): the sensor is measuring successive
accelerations, the data of which is stored internally. Slope d(acc_*)/dt is determined and
compared to a preconfigured any motion threshold. Interrupt or slope alert can be generated
when absolute value of measured slope is higher than the programmed threshold for long
enough duration. If slope is below any-motion-thresh-hold, Interrupt is reset. Slope interrupt is
performed, if at least 1 axis is leading to an interrupt (OR-connection).
Due to different devices (cell-phone, PND, lap-top, etc.) with different internal mechanical
constructions and placements of the sensor on a Printed-Circuit-Board (PBC), the sensor is
providing different parameters, the configuration of which is enabling device manufacturers to
optimize slope detection.
Figure 7: any motion detection with interrupt generation (schematic view)