122-28029 Parallax Inc, 122-28029 Datasheet - Page 244

• 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 232 · Smart Sensors and Applications
measurements were acquired with DatalogAcceleration.bs2 from Activity #4. After
displaying them in the Debug Terminal, they were shaded, copied and pasted into
Windows Notepad. From there, they were imported into the Microsoft Excel spreadsheet
program and then graphed.
The reason the forward acceleration is negative is because the y
to the back of the RC car as shown in Figure 6-6. So, as the car is accelerating forward,
the acceleration is negative.
backwards. This is shown in Figure 6-5. First, the car accelerated forward, then it
applied the brakes and slowed down (decelerated). The y measurement was positive, so
acceleration was negative. After a brief stop, the car accelerated backwards. Notice that
the y is again positive. Then, when it slows down (decelerates) from its backwards speed
to stop again, the car is, in effect, accelerating forward, and the y measurement is
negative again.
Decelerate
-10
-20
-30
-40
30
20
10
Accelerate
0
Forward
0
50
RC Car Forw ard and Backw ard
100
Stop
seconds/30
150
Decelerate
200
Accelerate
Backward
When a car slows down, it is actually accelerating
250
300
Figure 6-5
RC Car Accelerometer Y-
Axis Measurements
m
sensing axis is pointing