MMA8653FC datasheet(15/56 Pages) FREESCALE

15 / 56 page

MMA8653FC

Sensors

Freescale Semiconductor, Inc.

The motion configuration has the option of enabling or disabling a high-pass filter to eliminate tilt data (static offset); the freefall

configuration does not use the high-pass filter.

MMA8653FC has an interrupt architecture for detecting a Freefall.

•

Freefall can be enabled where the set threshold must be less than the configured threshold.

The freefall configuration does not use a high-pass filter.

5.5.1

Freefall detection

The detection of “Freefall” involves the monitoring of the X, Y, and Z axes for the condition where the acceleration magnitude is

below a user-specified threshold for a user-definable amount of time. The usable threshold ranges are normally between

±100 mg and ±500 mg.

5.6

Orientation detection

The MMA8653FC incorporates an advanced algorithm for orientation detection (ability to detect all 6 orientations), with one

default trip point setting. The transition from portrait to landscape is at a fixed 45° threshold angle and at a fixed ±15° hysteresis

angle. This allows for smooth transition from portrait to landscape at approximately 30°, and then from landscape to portrait at

approximately 60°.

The MMA8653FC 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”. The device operates at a fixed 29° angle from the flat position, with an accuracy of ± 2°.

•

Figure 7 shows the definition of the orientations (PU, PD, LL, LR, BACK, FRONT).

•

Figure 8 shows the definitions of the trip angles, going from landscape to portrait and then from portrait to landscape.

Figure 7. Landscape/Portrait orientation

Top View

Earth Gravity

Pin 1

X @ 0g

Y @ -1g

Z @ 0g

Xout @ 1g

Yout @ 0g

Zout @ 0g

Xout @ 0g

Yout @ 1g

Zout @ 0g

Xout @ -1g

Yout @ 0g

Zout @ 0g

Side View

FRONT

Xout @ 0g

Yout @ 0g

Zout @ 1g

BACK

Xout @ 0g

Yout @ 0g

Zout @ -1g

MMA8653FC датащи(PDF) 15 Page - Freescale Semiconductor, Inc

MMA8653FC датащи(HTML) 15 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56

датащи скачать

ссылки URL