28029 Parallax Inc, 28029 Datasheet - Page 97

• Manufacturer Part Number: 28029
• Description: KIT PARTS SMART SENSORS W/TEXT
• Manufacturer: Parallax Inc

Specifications of 28029

• Accessory Type: Parts Kit
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: BASIC Stamp® or Javelin Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 28029PAR

ACTIVITY #5: MEASURING 360° VERTICAL ROTATION
The MX2125 has a built-in feature that allows you to use both the x and y axis tilt
measurements to calculate the accelerometer's angle of rotation in the vertical plane, as
shown in Figure 3-15. There are lots of applications where vertical tilt is useful,
including virtual steering wheels for video games and counting bicycle wheel revolutions.
This activity demonstrates how to calculate tilt on the vertical plane with the PBASIC
ATN
Calculating Arctangent with PBASIC
The tangent of an angle theta (θ) in a right triangle is the ratio of the opposite side of a
right triangle (y) divided by the adjacent side (x). If you know the values of x and y, you
can use the inverse tangent or arctangent to figure out the angle θ. The most common
notations for arctangent are tan
√
√
√
√
√
operator.
Open SimpleTilt.bs2 from Activity #1 and save it as CentigravityTilt.bs2
Follow the steps for scaling from Activity #3 and determine the
scale constants.
Add lines of code to the program that scale the x and y values down to g/100.
Modify the display so that it shows in the Debug Terminal.
Test according to Figure 3-14 and troubleshoot if necessary.
−1
and arctan.
Chapter 3: Tilt with the Memsic Accelerometer · Page 85
Figure 3-15
Tilt on the Vertical Plane
**
operation