122-28029 Parallax Inc, 122-28029 Datasheet - Page 249

• 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

1.4 g for a little over 2 seconds. Then it rested for about 1 second. After that, it
accelerated backward, and then decelerated (accelerated forward) to a second stop.
Figure 6-10: Acceleration Graph Modified with Positive Acceleration Indicating Forward
A column with an equation was added to the spreadsheet that calculates the change in
velocity for each acceleration measurement. The equation for velocity in a straight line is
v = v0 + at. That's the initial velocity (v0) plus the product of the acceleration (a) and the
duration of that acceleration (t). Adding a column to the spreadsheet that recalculates
velocity between each acceleration measurement makes it possible to graph the velocity
as shown in Figure 6-11. As expected, when the car accelerates forward, its velocity
increases. Then, when it slows down, its velocity decreases. As it accelerates backward,
its velocity decreases further (increases in the negative direction). Then, as it slows its
backward motion, its velocity returns to almost zero.
Selecting Data to Graph. Right-click the line in the plot with the title "RC Car Acceleration
for Forward and Backward.” Then choose source data and click the Series tab. Note that
the series being plotted is from F229 to F492. This is the second of two forward/backward
tests that were performed during the datalogging session. The same applies to the Velocity
and Position graphs.
Chapter 6: Accelerometer Projects · Page 237