MMA8652FC datasheet(17/65 Pages) NXP

17 / 65 page

MMA8652FC

Sensors

Freescale Semiconductor, Inc.

Figure 7. Landscape-to-Portrait transition trip angles

The MMA8652FC orientation detection algorithm confirms the reliability of the function with a configurable Z-lockout angle.

Based on the known functionality of linear accelerometers, it is not possible to rotate the device about the Z-axis, to detect change

in acceleration at slow angular speeds. The angle at which the device no longer detects the orientation change is referred to as

the “Z-lockout angle” (see Figure 8). The device operates down to 14° from the flat position.

Figure 8. Z-Tilt angle lockout transition

PORTRAIT

Landscape-to-Portrait

Trip Angle = Midpoint + hysterisis value

0° Landscape

PORTRAIT

Portrait-to-Landscape

Trip Angle = midpoint - hysteresis value

0° Landscape

UPRIGHT

NORMAL

Z-LOCK

0° FLAT

DETECTION

REGION

LOCKOUT

REGION

When lifting the device upright from the

flat position, orientation detection will be

active for orientation angles greater than

a user-configurable value.

The default angle is 29° from flat, but the

angle can be set as low as 14°.

MMA8652FC Datasheet(PDF) 17 Page - NXP Semiconductors