122-28029 Parallax Inc, 122-28029 Datasheet - Page 104

• Manufacturer Part Number: 122-28029
• Description: GUIDE STUDENT SMART SENSORS
• Manufacturer: Parallax Inc

Specifications of 122-28029

• Accessory Type: Manual
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Smart Sensors
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

Page 92 · Smart Sensors and Applications
Measuring Tilt Angle On the Vertical Plane
The angle of your board's clockwise rotation in the vertical plane (θ) is the arctangent of
the gravity's effect on the MX2125's y-axis (A
shown in Figure 3-20.
Here are a few examples of what the accelerometer detects and how it relates to the
arctangent of the ratio of A
the 0° mark. If θ is 0°, then A
0/1 is 0°.
Figure 3-21: Accelerometer Rotated 0°
When the accelerometer is rotated 30° clockwise, as shown in Figure 3-22, the
component of gravity acting on the accelerometer's x-axis is approximately √3/2 g. The
tan
−
1
⎛
⎜
⎝
0
1
⎞
⎟
⎠
=
0
°
y
to A
y
senses 0-gravity (g), and A
x
. Figure 3-21 shows what the accelerometer senses at
θ
=
tan
y
−
) divided by its effect on its x-axis (A
1
⎛
⎜
⎜
⎝
A
A
Y
X
⎞
⎟
⎟
⎠
x
senses 1 g, the arctangent of
Figure 3-20
Clockwise Vertical
Rotation
x
), as