Question??
Who can text the fastest?
We want to test 2 students to find out who can text the fastest using the Lego Mindstorm brick and
2 touch sensors.
Name: _____________________________________________
Last
First
Name: _____________________________________________
Last
First
Background info:
What information might be useful to obtain an answer to the question? If you need to do research,
do so and include the references below.
Student 1: How much do you text? Do you use all fingers, 2 thumbs, or 1 finger to text?
Student 2: How much do you text? Do you use all fingers, 2 thumbs, or 1 finger to text?
Hypothesis:
We think there will be a tie. Both students are frequent text-ers and use all fingers to text.
Experimental design:
Experiment:
Touch Sensor Sound Sensor Light Sensor
Ultrasonic
Rotation
Temperature
Sensors Used 2 sensors-1
Sensor
Sensor
Sensor
(circle
for each
appropriate)
student
Port Used (1-4, A-C:numbered ports are inputs, lettered ports are output like running a motor) 1,2
1
Experimental Description:
(what and how will you measure?)
Experimental setup:
(draw a picture of your experimental setup)
Construct a device that can be used to
measure how many times each of you (2
students) can click the pushbutton in a set
length of time.
Some things to consider:
 Remote or real time?
 How frequently will you sample data?
 How long will you collect samples?
 How many data sets will you collect?
 How will you analyze your data?
Write the steps you will take to perform your
experiment:
1. Setup: Construct a device that can be
used to measure how many times you
and your partner can click a
pushbutton. Draw a picture of your
experimental setup in the next column.
2. We will use 2 touch sensors connected to ports 1 and 2 but to test our set up before
starting our actual experiment we will perform an experiment to record just 1 touch
sensor to see what happens. If our dataset with 1 sensor looks reasonable we will
then test with 2 students/2 touch sensors.
3. We will record in real time.
4. We will record data at 25 samples per second over 5 seconds.
5. We will perform our test at least 3 times.
6. We will start a new experiment each time so each data set is on a different
graph.
7. In analyzing our data we will make each person’s graph a different color.
8. We will fill in the below table to show the results of all datasets:
Dataset Student
1
touches
1
2
3
Total
Student
2
touches
Winner
Touches/second
9. We will count the number of touches for each student for each dataset and
record in our table.
10. We will determine which student has more touches for each data set (winner!)
11. We will decide if we can come to a conclusion based on our data; if not we
may need to do more experiments.
2
Read over your steps; be sure they will enable you to answer your hypothesis. If your
steps are accurate, do your experiments!
Observations:
Were you able to be consistent in the # of presses of the sensor over the 5 seconds?
Did you tire from the first dataset to the last dataset?
We only counted the # of touches; do you think the duration each “touch” affected the #
of touches/second?
Copy an example of one of your data logging graphs below. You can annotate your
graph to label each student’s data so that it will help answer your hypothesis.
Conclusion:
Was your hypothesis true or false?
3
Summary:
Chapter 2:
Touch Sensor Experiments
The Touch Sensor is capable of detecting whether it is pressed
in or not. This property can be used in several ways, most
commonly to count the number of times a specific event has
occurred.
Try it out!
Turn on the NXT. The initial display will show the ‘My Files’ menu. Navigate either left
or right until you locate the ‘View’ menu. Pressing the Orange ‘Select’ button on the
NXT will show the different sensors you can view.
Choose the ‘Touch Sensor’ and make sure it is plugged into ‘Port 1’. Any input port can
be used (1-4) providing the correct port is also chosen on the NXT screen.
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19
Touch Sensor Experiments
If you now press the Touch Sensor, you should find that it registers a ‘1’
when pressed and ‘0’ when released.
Press the dark grey ‘Exit’ button to move back up to the main menu.
Remember that a complete button press is defined as the button being
pressed in and then released. On the graph you will see the data go up
to ‘1’ when pressed and back to ‘0’ when released.
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