KXTIK-1004 Datasheet, PDF (41/54 Pages) List of Unclassifed Manufacturers – 2g/4g/8g Tri-axis Digital Accelerometer Specifications

± 2g / 4g / 8g Tri-axis Digital
Accelerometer Specifications
PART NUMBER:
KXTIK-1004
Rev. 2
Dec-2011
orientation change. When the device orientation angle approaches 0° (device is flat on a desk or table), a_x =
a_y = 0g, a_z = +1g, and there is no way to determine which way the screen should be oriented, the internal
algorithm determines that the device is in either the face-up or face-down orientation, depending on the sign of
the z-axis. The KXTIK will only change the screen orientation when the orientation angle is above the factory-
defaulted/user-defined threshold set in the TILT_ANGLE register. Equation 2 can be used to determine what
value to write to the TILT_ANGLE register to set the device orientation angle.
TILT_ANGLE (counts) = sin θ * (32 (counts/g))
Equation 2. Tilt Angle Threshold
Tilt Timer
The 8-bit register, TILT_TIMER can be used to qualify changes in orientation. The KXTIK does this by
incrementing a counter with a size that is specified by the value in TILT_TIMER for each set of
acceleration samples to verify that a change to a new orientation state is maintained. A user defined
output data rate (ODR) determines the time period for each sample. Equation 3 shows how to
calculate the TILT_TIMER register value for a desired delay time.
TILT_TIMER (counts) = Delay Time (sec) x ODR (Hz)
Equation 3. Tilt Position Delay Time
Motion Interrupt Feature Description
The Motion interrupt feature of the KXTIK reports qualified changes in the high-pass filtered acceleration
based on the Wake Up (WUF) threshold. If the high-pass filtered acceleration on any axis is greater than the
user-defined wake up threshold (WUF_THRESH), the device has transitioned from an inactive state to an
active state. When configured in the unlatched mode, the KXTIK will report when the motion event finished
and the device has returned to an inactive state. Equation 4 shows how to calculate the WUF_THRESH
register value for a desired wake up threshold. Note that this calculation varies based on the configured g-
range of the part.
WUF_THRESH (counts) = Wake Up Threshold (g) x Sensitivity (counts/g)
Equation 4. Wake Up Threshold
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