Application Note
BlueBox Demo-Board for the digital sensors
SMB365 (acceleration) and SMD500 (pressure)
Bosch Sensortec
AN18002
Rev. 1.0
Page 39
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7211RB11.
• Select any acceleration range [21]
• Select independent interrupt mode [22]
• Put in Hysteresis and Threshold digits for X, Y and Z axis [23]
• Start data acquisition [8]
• accelerate, roll or tilt the TriBox board while watching the interrupt LED [25]
For Interrupt operation as a function of Threshold and Hysteresis the same as shown in chapter
4.3.2 before applies with one exception. Threshold and Hysteresis can be selected individually
for each axis. For Hysteresis set = Zero, the following logic applies, e.g.:
LED [25] = 1 if LSB
X
> Threshold
X
OR LSB
Y
> Threshold
Y
OR LSB
Z
> Threshold
Z
LED [25] = 0 if LSB
X
< Threshold
X
AND LSB
Y
< Threshold
Y
AND LSB
Z
< Threshold
Z
For Hysteresis set ≠ Zero, the following logic applies, e.g.:
LED [25] = 1 if LSB
X
> Threshold
X
OR LSB
Y
> Threshold
Y
OR LSB
Z
> Threshold
Z
LED [25] = 0 if LSB
X
< Hysteresis
X
AND LSB
Y
< Hysteresis
Y
AND LSB
Z
< Hysteresis
Z
The following example shows how to set up the axis specific Threshold and Hysteresis. The
calculation corresponds to the low g operation mode:
Threshold:
gmgLSBLSBd 28.16420320162020 =⋅∝=⋅=
Hysteresis:
gmggLSBLSBLSBd 02.1256128.12566413201 =⋅−∝=⋅−=
If Hysteresis is equal or above Threshold (LSB values), the interrupt functionality will be
disabled. For a total reset of the sensor internal interrupt information just switch to standby
mode [20] and continue.
