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MMA865xFC Sensor Toolbox User’s Guide, Rev. 0
56
Freescale Semiconductor, Inc.
The elements of this shake-detection screen are described in the following table.
Table 17. Full-System Evaluation – Transient Detection screen
Screen
frame
Element
Description
Transient
Detection
Settings
Note
:
Before
configuring
the
settings,
the Default
Transient
settings
checkbox
must be
unchecked.
Default Transient
Settings
Restores all transient-detection settings to the factory default values.
Bypass HPF
HPF = High-Pass Filter
Directs the application to use the raw accelerometer data before it (the raw data) has
been passed through the HPF. The Bypass HPF setting should normally be disabled.
• Enable X Flag
• Enable Y Flag
• Enable Z Flag
Allows shakes along these axes to trigger the “Event Detected” Indicator on the Demo
Screen.
Enable Latch
Causes any triggered event to remain until the Status register is read. If the Enable
Latch checkbox is not enabled, then the interrupt will only last as long as the event,
and the Status register will represent the most-recent event.
Threshold
slider
Sets the threshold for the minimum g force required for a shake event to be detected.
Shakes at a smaller g-force than this value are filtered out.
• To move the Threshold slider, the Reset button must be clicked.
• After moving the Threshold slider, click the Set button to change the setting.
Debounce
slider
Sets the minimum time that a shake must last, for a shake event to be detected.
Set
After changing the Debounce slider, click Set to register the new settings with the
device.
Reset
Before configuring the Debounce slider, click Reset to enable the new configuration.
Decrement
Debounce
Causes the Debounce timer to be decremented, for each time that an event fails to
reach the debounce time.
Clear Debounce
Causes the timer set by the Debounce slider to reset, for each time that an event fails
to reach the debounce time.
Transient
Detection
Indicator
(Read only)
• X Direction X
• Y Direction Y
• Z Direction Z
The indicator(s) switch from red to green when an event is detected along the
specified axis or axes.
Event Detected
This indicator switches from red to green if a transient event is detected.
LPF / HPF
Data Plot
This frame’s label displays Low-Pass Filter Data Out or High-Pass Filter Data Out, depending on whether
the HP Filter option button has been enabled on the Full-System Evaluation demo’s Operation Mode
screen.
• X-Axis
• Y-Axis
• Z-Axis
Each checkbox enables the collection of data along the selected axis or axes.
(Graph)
Displays the data acquired by the accelerometer.
• X-Axis
• Y-Axis
• Z-Axis
These graph-legend entries give the line color for the respective axes. (Read only)