Robotics 9 - Hawkeye888.net

Robotics 9 - Hawkeye888.net
Classroom Activities for the Busy
Teacher: NXT
2nd Edition
Classroom Activities for the Busy Teacher: NXT
Copyright © 2011 by Damien Kee
ISBN – 978-1467920360
All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means,
physical or electronically, without the prior written permission of the author.
"LEGO, the brick configuration, and the minifigure are trademarks of The LEGO Group, which does not
sponsor, authorize, or endorse this book.”
The information in this book is distributed on an „as is‟ basis, without warranty. Although every precaution
is taken to ensure the accuracy of this information, the author assumes no liability to any person or entity
with respect to loss or damage caused, or alleged to be caused directly or indirectly, by the information in
this book.
About the Author
Dr Damien Kee holds a PhD in Robotics and a Bachelor of Electrical
Engineering, both from the University of Queensland, Australia. During
his time at the University of Queensland, Damien was the team leader of
the Humanoid Robot project that travelled to Japan to compete in
RoboCup (2002), as well as the co-team leader of the Mechanical
Engineering Student Robotic team that also travelled twice to Japan to
compete in RoboCon (1999, 2000). He has built a wide variety of
robots, from maze solving mice to humanoids, to robots that could
dispense traffic cones.
Damien has been heavily involved with the RoboCup Junior competition since 2001, initially as a judge,
and more recently as one of the QLD State competition technical organisers. In 2007, Damien was the
Chair of the Organising Committee for the 2007 RoboCup Junior Australian Open that ran successfully
with over 140 teams from 3 countries. He has been Chairman of the RoboCup Junior Australian
Committee and is the Australian representative to the RoboCup Junior International Committee.
Damien is a member of the LEGO® MINDSTORMS® Community Program, a group of approximately 50
people around the world who consult with LEGO® to make the MINDSTORMS® system a better
product. He is also editor-in-chief of the highly popular theNXTstep Blog (www.thenxtstep.com), the
leading website for LEGO® MINDSTORMS® users.
Table of Contents
Chapter 1:
Introduction .......................................................................................... 1
Chapter 2:
What is a robot? ..................................................................................... 5
Chapter 3:
Flowcharting ........................................................................................11
Chapter 4:
DomaBot Basics .................................................................................. 15
Chapter 5:
How far? .............................................................................................. 25
Chapter 6:
How fast? ............................................................................................. 29
Chapter 7:
That bot has personality! .................................................................... 35
Chapter 8:
How many sides? ................................................................................ 41
Chapter 9:
Help! I'm Stuck ................................................................................... 47
Chapter 10: Help! I'm (still) stuck ......................................................................... 53
Chapter 11: Stay Away from the Edge ................................................................... 59
Chapter 12: Did you hear that? .............................................................................. 65
Chapter 13: Mini-Golf............................................................................................. 70
Chapter 14: Dancing Robots .................................................................................. 74
Chapter 15: Robot Wave ......................................................................................... 78
Chapter 16: Robot Butler........................................................................................ 82
Chapter 17: As seen on TV! .................................................................................... 84
Chapter 18: Meet your adoring public! .................................................................. 86
Chapter 19: Student Worksheets ............................................................................ 89
Chapter 20: Building Instructions ....................................................................... 109
Chapter 1:
Introduction
This book is a guide for teachers implementing a robotics unit in the classroom. It is aimed at middle years
schooling (ages 9 - 15) but the wide range of activities can be adapted to suit older or younger students.
The book is based around a single robot, the DomaBot, which is used in all activities. This approach is
valuable in resource limited classrooms, as it allows the teacher to work with a 'standard' robot, rather than
using valuable classroom time building and breaking down robots each lesson.
It is assumed that the teacher has a basic knowledge of how to open the NXT-G programming
environment and how to download a program to the NXT unit.
The book is divided into sections that follow a 10 week plan, although this can be modified to suit the
needs of the teacher. The first 4 weeks takes students through a series of activities, progressively exposing
them to new aspects of the NXT-G programming environment. Following that, is a set of open ended
challenges from which teachers may pick and choose to suit their particular class.
All challenges include the following information:






Scenario setup + background information. Teachers are free to develop each scenario further as
they see fit.
Equipment list. Aside from the standard NXT robotics kit, all other required resources are easily
sourced within a school environment.
Teacher notes are provided on common issues that may arise with each challenge and how they are
best dealt with.
Programming examples in the NXT-G development environment.
Student worksheets to fill out (photocopy permission provided).
Extension activities.
1
Introduction
Lesson Plan
The following is a lesson structure for a 10 week unit on robotics. This plan assumes approximately 5
hours of content per week in class, although the ability of the students involved may require slightly more
or less time as needed.
Week 1: Introduction
Students are introduced to robotics in general. Their use in society and the differences between fictional
and real robots are described and the fundamental components of a robot are discussed. Students are
asked to prepare a report on robots. Student worksheet – What is a Robot? is handed out with the due
date left to the teacher‟s discretion.
Week 2: Organisation
NXT kits are sorted to ensure all pieces are accounted for. The concept of flowcharting is presented, and
backed up by worksheet - Flowcharting. During this week students will also build the DomaBot or
another equivalent robot. Students can continue to work on the previous week‟s assignment.
Week 3: DomaBot Basics
Students will learn how to use the NXT-G programming language to move their robot around the floor
using Student worksheet – DomaBot Basics. The „Move‟ block is the focal point of this week‟s challenge.
Week 4: How Far, How Fast: Data collection
Following on from the previous week, students will use their robots to learn about velocity and data
collection.
Week 5: How Many Sides?
The drawing attachment is constructed and mounted onto the robot. Students will learn about the „loop‟
structure as well as building on their knowledge of geometric shapes. Polygon properties such as internal
and external angles are discussed.
Week 6: Help! I’m Stuck! + Help! I’m Still Stuck
The concepts of sensors are introduced and the Touch Sensor and Ultrasonic Sensors are used to assist the
robot with navigation. Students give their robot the intelligence necessary to make decisions for itself.
2
Introduction
Week 7 Stay Away from the Edge + Did you Hear that?
Additional sensors are presented to round out the full complement of standard NXT sensors available.
The Light Sensor and Sound Sensor are connected and provide additional sources of information to the
robot.
Week 8: Major Project (Mini- Golf, Dancing Robots, Robot Wave or Robot Butler)
Teachers may choose one or a number of these activities for the students to undertake. They may work in
small or large teams, each with a few robots per team. Student may wish to pursue their own project, in
consultation with the teacher.
Week 9: Major Project
Students continue working on their major project.
Week 10: As Seen on TV!
Students develop a multimedia marketing presentation with which to „sell‟ their robot to consumers. This
may take on any number of media formats (website, speech, newsletter article etc.)
Resources
Extra resources that complement this book can be found on the website
http://www.damienkee.com
3
Introduction
4
Chapter 2:
What is a robot?
Overview: Discover what a robot is, and what function it performs.
Project: Students are asked about what they think a robot is, and what it does. Students research robots in
general and present a report based on one particular robot.
Equipment


Access to research materials, (Library, Internet etc)
Computer to write report
Teachers Notes
This section will cover the following concepts





Research skills
Report writing
Word Processing
Design with Multimedia
Oral presentation
Photocopy Student Handout 1 and distribute to the class. You may choose to start discussion immediately
or give the students time to perform preliminary research. Bring the group together and start to form a
class opinion of robots.
Answer the following questions as a group.





What is a robot?
Where did the term 'robot' come from?
Name some types of robots
Why do we have robots / What function do they perform in society?
What are the main components of a robot?
5
What is a robot?
There are many different interpretations of what a robot is, with some of them quite different. There is no
single definitive answer that encapsulates all the functions of a robot. The following is a list of different
dictionary definitions available.
American Heritage Dictionary
“A mechanical device that sometimes resembles a human and is capable of performing a variety of often complex
human tasks on command or by being programmed in advance.
A machine or device that operates automatically or by remote control”
Cambridge Advanced Learner's Dictionary
“a machine used to perform jobs automatically, which is controlled by a computer”
Oxford Dictionary
“a machine capable of carrying out a complex series of actions automatically, especially one programmable by a
computer.”
Keep in mind that while there is no universally accepted definition of a robot, the following points seem to
cover the vast majority of robots.




A robot is artificial. It has been manufactured and does not occur naturally.
It is controlled by a computer of some description. This may range from a full sized personal
computer to a small embedded micro-controller.
It can sense the surrounding environment
It can perform actions movements
Despite these requirements, it is still very difficult to categorise a robot. The question
can be posed to students; Is a washing machine a robot?




It is artificial
Modern washing machines are controlled by miniature computers inside them.
They can sense when the lid is open.
They perform movements by spinning the clothes back and forth.
Could railway boom gates be consider a robot?




They are artificial
They are controlled by computers
They can sense when a train is approaching
They can raise and lower the boom gates
6
What is a robot?
Why do we have Robots?
There are many reasons that robots are used in society, each one filling a particular need. This question
may also be posed as:
“What advantages are achieved by having robots in certain situations?”
Robots are generally built to serve for what is commonly known as the 3 D's; Dull, Dirty and Dangerous.
In an industrial setting, the use of robots allows repetitive tasks to be performed accurately time after time.
Robots can generally perform simple task far quicker than humans can. This leads to increased
productivity and better quality control of goods. Some types of robots, particularly those that need to pick
up and put down fragile items, are so accurate that they can stop within a human hairs width of the objects
they need to manipulate. Medical robots are reaping the benefits of such accuracy, allowing doctors to
perform surgery on patients who are in another city or on the other side of the world.
Exploratory robots and military robots are designed to keep people away from harmful situations. Robot
operators can drive a robot into an unsafe area, and use the sensors and cameras on board to gather
information. This is particularly useful for search and rescue missions in disaster areas, where the
environment may be unsafe for humans to go looking for survivors.
Entertainment robots provide a lot of fun and interest for people. They can be typically found on TV,
highlighting the fun things that robots can do. The range of sophistication goes from the very complex
humanoids such as ASIMO and QRIO, to the toys like RoboSapien and the LEGO® NXT system.
Household robots such as the vacuuming Roomba was one of the first robots to be marketed as a
domestic robot. Later versions have been developed that will also mop our floors and clean our gutters.
The dream of a robotic butler to pick up our clothes and do our chores is not far away.
Name different types of robots?
There are a variety of different categories for robots, including but not limited to:







Entertainment (ASIMO, QRIO, AiBO, animatronics, RoboSapien, LEGO®)
Domestic (Roomba, automatic lawn mowers)
Movies (C3PO, R2D2, Terminator, Johnny 5)
Industrial (welding, Pick and Place, factory automation)
Medical (remote surgery, minimally invasive surgery)
Exploratory (Mars rovers, deep sea ROV's, unassisted aerial vehicles)
Military (PackBot, bomb disposal, search and rescue)
7
What is a robot?
What are the main components of a robot?
Robots can be broken down into three distinct components; sensors, computation and actuators.
Sensors are used to 'feel' the surrounding environment. The robot uses these sensors to take in
information about where it is and what it is doing. Different sensors can be used to sense different
conditions including light and dark, temperature, bump sensors, ultrasonic, infrared… the list goes on and
on. Think about what sensors a human has, and how a robot replicates them. Sensors are classed as
inputs, that is, they take information and input it into the robot‟s brain.
The computation component consists of an onboard computer that the robot uses to process the
information coming from its sensors. This can be as small as a few computer chips right through to a full
personal computer. The level of complexity of the required tasks will dictate the amount of computational
ability needed by the robot.
The last distinct component of a robot is its actuators. Actuators are a fancy way of saying 'bits that move'.
These may be motors in the wheels, or engines that make the arms go back and forth. It could also be
hydraulic pistons or pneumatic cylinders. Actuators are a form of outputs, along with lights and speakers.
The robot brain tells these outputs to do different tasks.
Generally speaking, the sensors provide the information to the computers, which in turn tell the motors
what to do.
Sensors
information
Computation
information
Actuators
Path of information flow in a robot
Where did the term 'Robot' come from?
While the idea of artificial beings have been around for many years, the term 'robot' was first coined by
Czech writer Karel Čapek in his play R.U.R. (Rossum's Universal Robots) in 1920. The word is derived
from the Czech 'robota', which translates as 'forced work', 'slave' or 'servitude'. Čapek credits his brother
Josef as the true inventor of the word.
Robots have enjoyed the majority of their exposure through movies and science fiction writings, such Star
Wars and the Asimov series of 'Robot' books.
Robots in their presently accepted state were first developed in the 1950's, with George Devol's Unimate
robot, capable of lifting hot pieces of metal from a die casting machine and stacking them. The first
Unimate was sold to a General Motors assembly plant in New Jersey.
8
What is a robot?
Assessment
Students are to present a report on robots. This may be done as a report, PowerPoint presentation, poster
or oral report. Students will give a brief overview of robotics based on the preceding discussion and
perform a more in depth analysis of one particular robot as approved by the teacher.
The following is a good list of real world robots.




ASIMO, QRIO, AIBO, Roomba
Spirit / Opportunity
Pathfinder Sojourner
PUMA arm, SCARA arm
Decide on the format of the assignment (written, oral, multimedia) and hand out the Student Worksheet –
What is a Robot?. The due date is left to the teacher discretion.
Extension activities
Any of the following questions could be used to promote further discussion:





What are the differences between real robots and fictional robots?
What attributes of robots are still only being dreamed about?
Should robots have rights?
Does a robot have a right to be cared for and maintained?
Is there such a concept as robot abuse?
Watch the movie or read the book 'Bicentennial Man'


Should a robot be compensated for its work?
What form should payment entail? Monetary? Upgrades?
Watch the movie or read the book „I, Robot‟



Can robots be charged with a crime?
If someone is injured by a robot, is it a crime or a malfunction?
Will robots make some jobs redundant?
Robots are replacing many people who work in dull, dirty or dangerous jobs.



Will robots working in dull jobs force people to learn more complex skill sets?
Will the proliferation of robots result in more robot maintenance jobs?
What other new technologies have threatened jobs in the past? Industrial revolution etc.
Look into the RoboCup mission for 2050
"By the year 2050, develop a team of fully autonomous humanoid robots that can win against the human world
soccer champion group."
9
What is a robot?
10
Chapter 3:
Flowcharting
Overview: An introduction to flowcharting
Project: Students are introduced to the concept of flowcharting. This process will allow them to coordinate their thoughts and will make programming less difficult as they progress. A larger project is
systematically broken down into a series of more manageable tasks that are more readily completed.
Equipment


Blackboard / Whiteboard
Markers
Teachers Notes
This section will cover the following concepts


Flowcharting / storyboarding
Progression of actions
This section is best done on a whiteboard or blackboard. The concept of a flowchart should be explained
with emphasis on both the correct order of tasks and providing sufficient detail. With both these concepts
understood, generating a program for a robot becomes considerably easier.
Theory
When planning the program for a robot, it is very beneficial to go through a flow charting process. Flow
charting allows us to take the ideas we have for a robot, and start to assemble them in a logical fashion.
11
Flowcharting
As an example, let us have a look at a typical student morning. We will look at how we approach our
morning as a series of different individual tasks. First up, we need to get the order in which we do each
step the right way around. If we try and do things in the wrong order, the whole day may not work. In
addition, the amount of detail for each task is important. Each step should be sufficiently small enough, so
as it can be done as a single step. If we keep these tasks short and simple and concise, it is easier plan out
the bigger tasks. Occasionally, some steps need to be revisited and broken down further into smaller steps.
Go to School
Wake Up
Get out of Bed
Get out of Bed
Have Breakfast
Have Breakfast
Wake Up
Go to School
Wrong
order!
Correct
order
The order in which we do each task is very important. If we get the order around the
wrong way, the tasks will not make sense.
When we start programming our robots, we will also need to sketch out a flowchart of how we would like
our robot to behave. If we can break down the whole program into little tasks like we did above, it will be
easier to program our robot. Ideally, each individual task will relate directly to a single block in the NXT-G
programming environment. Once we have this sequence of tasks, we can start putting them into a
language that the robot will understand. We will be using the NXT-G programming language to make our
robot perform each of these tasks that we have defined.
It is important to remember that the first draft is not expected to be perfect. Changes will almost certainly
have to be made along the way as flaws and inconsistencies are found. It will need to be stressed that it is
vital to have a plan or road map first, before we start programming, even if that plan changes along the
way.
12
Flowcharting
Wake Up
Wake Up
Have Breakfast
Get out of Bed
Get out of Bed
Get Schoolbag
Have Breakfast
Get Dressed
Catch Bus
Go to School
Go into Kitchen
Go to School
Not enough detail
Better flowchart with more detail
How much detail we put into our flowchart is important. The one on the left has only a few broad steps.
The one on the right is far more detailed and would be easier to convert into a program.
Assessment
Photocopy and hand out Student Worksheet - Flowcharting. Lead the class in a discussion about
flowcharting and have the students complete the worksheet. Emphasise the need to have the correct order
of tasks as well as sufficient detail.
13
Flowcharting
14
Chapter 4:
DomaBot Basics
Overview: Build a robot that is capable of driving around an obstacle course.
Project: NASA is in the market for a new planetary rover to explore the recently discover planet NXTopia.
You are required to design and construct a robot that is capable of following a set of commands to explore
the planet's surface. Before the robot is deployed, it must be extensively tested to ensure it will perform as
expected. You can't fly a technician to NXTopia to reboot the robot!
Equipment required




1 NXT robot kit per group
1 computer per group
Masking tape
Tape measure
Teachers Notes
This section will cover the following topics amongst others




Basic numeracy
Decimal and fractional numbers
Relationship between diameter and circumference
Conversion between millimetres and inches
Get the students to build DomaBot robot presented in Building Instructions.
Photocopy and hand out Student Worksheet – DomaBot Basics. This worksheet gives the students a
range of different activities to follow that progressively increase in difficulty.
NXT-G Specific
To perform the programming, we will need to know about the Move block from the common palette.
The Move block as its name implies, controls the movement of up to 3 motors. The diagram below shows
the Move block and its associated properties.
15
DomaBot Basics
Move Block
Port: This selects which port the motor is connected to. The default is ports B and C which is identical to
the DomaBot design.
Direction: Is the motor going in a generally forward direction or generally backward direction or is it
stopped altogether?
Steering: The steering angle is controlled via the slider bar at the bottom of the configuration panel. This
will range from a gentle turn to a tight turn on the spot depending on how far this slider is taken. For a
student's perspective have a look at a bicycle. If we turn the handle bars a little, we get a gentle curve. The
sharper we turn the handle bars, the smaller the turning circle we will get.
Gentle Turn
Sharp Turn
The slider itself however does not control how far the robot travels. Take the analogy of the car. We can
turn the steering wheel all we want, but if we don't put our foot on the accelerator, then the car will not
move at all. The distance travelled by the car (either in a straight line or in a curve) is determined by the
'duration' that the accelerator is held down for.
16
DomaBot Basics
Power: This slider controls how fast the motor goes. Be aware that at low speeds the motor may not
have enough torque (turning force) to make the robot move. Generally speaking, power levels of 10-100
are appropriate for most robot designs.
Duration: The most important property of the configuration box. This will control how long the motor
will turn for. There are 4 options, unlimited, degrees, rotations and seconds. For the first few sections, we
will be using just the degrees and rotations options. These refer to how far the wheels of the robot turn.
Next Action: We can specify what we need the motor to do after it has completed its required duration.
The two options are brake and coast. The difference between each property is the same as in a real car. If
the brakes are applied, the motor come to a sudden stop. If it is allowed to coast, the robot is allowed to
slowly come to a stop.
Theory
The first step required is to characterise the robots performance. This means, take measurements to
determine the specifications of the robots movement. This is a good opportunity to either reinforce or
introduce the correlation between the radius of a wheel and its circumference.
Calculating the circumference can be done either mathematically or experimentally depending on the ability
of the students.
Mathematically: The circumference of a wheel can be calculated using the formulae: c=π×d
Where c= circumference, π = 3.14 (approx) and d is the diameter of the wheel.
The wheel that comes as part of the standard NXT set is 56mm (2.2 inch) in diameter which results in a
circumference of approximately 176mm (6.9 inch).
Experimentally: Take a wheel off the robot and make a mark on the tire with either chalk or masking
tape. Create a starting mark on the table and line up our tire mark with it. Now slowly roll the wheel until
the tire mark again touches the ground. Make another mark at this point and use a ruler to measure the
distance.
Circumference
17
DomaBot Basics
For the challenge where students are asked to make their robots turn 180 degrees, they will typically type in
180 degrees and download it. When they come to run the program though, they will find that their robot
will not actually turn 180 degrees but in fact, if they are using the DomaBot design, it will only turn 45
degrees.
This behaviour occurs because the move block is designed to control the wheel of the robot, not the whole
robot. If we observe the wheel, we will find that it does in fact turn exactly 180 degrees, just as it was told
to do. The angle turned by the robot however is dependent on a few different conditions such as the size
of the wheels and the distance between the wheels. To test, place a strip of tape on the floor. Start the
robot with both wheels on the tape. A perfect 180 degree turn will result in the wheels ending up back on
the tape.
Calculating the required duration to make the robot turn 180 degrees can be done either mathematically or
experimentally depending on the ability of the students.
Mathematically: The robot needs to trace out half a circle that is defined by the distance between the 2
wheels. On the DomaBot, this is 168mm (6.6 inch).
168mm / 6.6 inch
This distance can be calculated as half the circumference of a 168mm (6.6 inch) diameter circle.
18
DomaBot Basics
We know from the previous exercise that the circumference of the wheel is 176mm (6.9 inch). We know
that the wheel must travel 264mm (10.4 inch) to perform a half circle robot rotation so the duration the
wheel must turn can be calculated as follows:
Experimentally: Keep increasing the duration parameter until the robot does indeed turn 180 degrees.
Students perform trial and error with different values until an acceptable solution is found.
Why is my robot not perfect?
Using the standard DomaBot design, the wheels should be located 168mm (6.6 inch) apart. If those wheels
happen to slide along the axles shafts, this will make the wheel base slightly larger and will change how
many degrees are required to do a full 180 degree robot rotation.
Let us take the example that the wheels are 1mm further out on both sides, giving a total wheel base of
170mm. We now have a required travel distance of:
The duration required for the wheels to travel 267mm is:
Larger spacing of the wheels will result in a larger required duration.
Look out for...
Layout two strips of tape, 500mm apart as our test distance. The 180 degree turn may introduce a slight
offset, requiring a little more duration on the 3rd block to drive back to the starting point.
The duration required to go 500mm (OR 20 inch) can be calculated by dividing 500mm by the
circumference of the wheel (176mm / 6.9 inch).
19
DomaBot Basics
When running the 'figure of eight' challenge, we can leave it open ended or can specify the shape we
require. Encourage the students to draw a picture of the path they are attempting before they start
programming. Encourage them to look at each of the individual movements, and relate them back to
separate Move blocks. To create a test environment, place 2 markers down, 500mm (20 inch) apart. The
robots will need to perform their runs around these markers and are not allowed to hit or move the
markers. Robots should ideally make it back to where they start.
Here are a variety of different ways of tracing out a 'figure 8'. The digital figure of 8 is the easiest to
implement, as the students already know how to drive straight and perform 90 degree turns.
20
DomaBot Basics
Example Programs
Drive Forward for 90° of the wheels
Drive Forward for 0.25 rotations of the wheels
Program your robot to move 3 rotations and measure how far it goes.
21
DomaBot Basics
Drive Forward 540° slow, then 540° back as fast as possible
Turn the robot around 180° (The WHEEL needs 540 degrees for the ROBOT to turn 180 degrees)
22
DomaBot Basics
Drive forward for 500mm, turn around 180° and drive back to where you started
23
DomaBot Basics
24
/ How far?
Chapter 5:
How far?
Overview: Test the robot for distance characteristics
Project: In the initial construction of the robot the travelling characteristics are required. After
characterising the properties, NASA have asked that you use your data to make predictions about the
distance your robot will travel given specific time constraints.
Equipment required





1 NXT robot kit per group
1 computer per group
Masking tape
Tape measure
Stopwatch
Teachers Notes
This section does not require any additional software knowledge. All activities can be performed with the
use of just the Move block. The DomaBot is used to perform data gathering and scientific analysis.
Photocopy and hand out Student Worksheet – How Far?.
This section will cover the following topics






Data gathering
Graphing
Interpolation / Extrapolation
Decimal numbers and fractions
Averaging of data
Position and distance
25
/ How far?
Theory
This activity will look at the effect changing the time of travel of the robot has on the distance it moves. It
will become evident that the longer a robot travels, the further it travels but can the relationship between
time and distance be predicted?
Students will program their robot to travel for 1 second at a specific power level. The same experiment is
run again this time for 2 seconds at the same power level. Students should take as many measurements as
time allows with a wide variety of times. Encourage the students to take multiple runs and take the average
of all their data to reduce the impact of any experimental error.
By plotting the distance travelled (vertical axis) against the time programmed (horizontal axis) students are
able to build up a graph of their data. Students should find that there is a linear (straight line) relationship
between the time programmed and the distance travelled. The slope of this line is the velocity of the robot
(distance/time).
A random power level between 50% and 100% is assigned to each group, resulting in different results for
each group. They cannot copy another group‟s data as it would be inaccurate for their robot.
This data was taken for the standard DomaBot running at 8.2V battery power. Lower battery levels will
change the speed of the robot so ensure that all data is gathered in one session, using the same robot each
time.
26
/ How far?
Look out for...
To set up, we will need a starting line and a tape measure. Encourage the students to work out what
materials they will need and gently push them in the right direction if they miss out on anything.
If this same experiment is run on carpet, students can expect to see a decrease in the distance of the robot
due to the additional friction between the castor wheel and the carpet surface. Encourage this line of
thought and get the students to run the same experiment, the same power level on multiple surfaces.
To test that the graph is correct, place an object a random distance away from the starting line. Students
will then need to read off their graph through either interpolation (reading within the graph) or
extrapolation (reading beyond the graph) to determine the amount of time required to reach the marker.
As an added parameter, require the robots to drive up to the marker but not knock it over.
Eg. Place a drink bottle 120cm (47 inches) away. Looking at the graph above, the DomaBot robot would
require approximately 4.25 seconds to reach that distance. All groups will have constructed their graphs
with different power levels and as such all groups should have a different time requirement.
Example Programs
Make your robot drive forward for 2.5 seconds at 72% power
Adjust this number to
change the travelling time
27
/ How far?
28
Chapter 6:
How fast?
Overview: Test the robot for speed and velocity characteristics
Project: To accurately be able to command the robot, you need to understand how fast it can go and what
properties may change its performance. NASA have requested a detailed report, supported by data that
you have gathered from your robot.
Equipment required





1 NXT robot kit per group
1 computer per group
Masking tape
Tape measure
Stopwatch
Teachers Notes
This section does not require any additional software knowledge. All activities can be performed with the
use of just the Move block. The DomaBot is used to perform data gathering and scientific analysis.
Photocopy and hand out Student Worksheet – How Fast?.
This section will cover the following topics






Data gathering
Graphing
Interpolation / Extrapolation
Decimal numbers and fractions
Averaging of data
Speed and Velocity of a moving body
29
How fast?
Theory
Students will need to understand the nature of speed and velocity. The speed of the robot is given as the
distance travel within a specified time. This may take on a number of forms such as kilometres per hour,
meters per second, feet per second etc.
The speed of the robot will be dependent on the power level as well as the weight of the robot. A heavier
robot will take longer to complete the 5 rotations than a lighter robot. If we are using the DomaBot, we
should find that a duration of 5 rotations will allow the robot to move a reasonable distance to measure.
Encourage the students to take multiple runs and take the average of all their data to reduce the impact of
any experimental error.
When plotting this data, the students will find that there is not a straight line relationship between the
power level and the time taken to complete 5 rotation of the wheel. The student will have to sketch out a
curve to best fit their data. The more data points we can gather, the more accurate we will be to fit the
curve.
This data was taken for the standard DomaBot running at 8.2V battery power. Lower battery levels will
change the speed of the robot so ensure that all data is gathered in one session, using the same robot each
time.
30
How fast?
A graph of Speed against Power can be graphed by determining the distance travel over 5 rotations
(879mm OR 34.6 inches)
To determine the speed of the robot for each data point, divide the distance travelled over 5 rotations, by
the time taken over 5 rotations.
eg.
If our robot takes 8.2 seconds to travel 5 rotations, then the speed can be calculated as follows;
With this data, students should now find a straight line relationship between speed and power level.
31
How fast?
Look out for...
To set up, we will need a starting line a tape measure and a stopwatch. Encourage the students to work out
what materials they will need and gently push them in the right direction if they miss out on anything.
When working with a fixed distance as in the case of the first section, we will be able to mark out a finish
line as well as a start line. This is useful for students to visually see when the robot reaches 5 rotations
rather than stopping the timer when the robot stops.
Smart students will program their robot to drive forward for the 5 rotations, wait a few seconds then
reverse back to the start to save the operator from retrieving the robot.
Once they have calculated the speed for their robot, have them run a few tests on an untried power level
and check that they do indeed travel at their desired speed. The robot may have a small margin of error
If this same experiment is run on carpet, students can expect to see a decrease in the speed of the robot
due to the additional friction between the castor wheel and the carpet surface.
Example Programs
Make your robot drive forward for 5 rotations at 50% power
Adjust this slider to
change the power level
32
How fast?
Extension activity
Build a small platform above the robot that can support the weight of a book. The DomaBot can take up
to 2kg in weight if distributed carefully. Students will find that their robot will move considerably slower
than before. Run the same set of experiments with this new 'heavier' robot.
Run the same experiments on several different surfaces to investigate the effect of friction on the robot.
Good surfaces to test could include:




Thin carpet
Thick carpet
Polished wooded floorboard
Concrete
33
How fast?
34
That bot has personality!
Chapter 7:
That bot has personality!
Overview: Use the Sound and Display blocks to give your robot some personality.
Project: NASA are extremely happy with the progress of the project so far, but have asked if it is possible
to inject a little personality into your robot. Using the in-built sounds as well as the display screen, it will
be possible for the robot to let us know what it is up to!
Equipment Required:


1 NXT robot kit per group
1 computer per group
Teacher Notes
As well as being a lot of fun, the use of sound and display is an excellent way of „debugging‟ programs. By
making the robot say a certain phrase at a particular point in the program, students can figure out if it
reached that point, just by listening out for it. Eg. Suppose we wanted the robot to perform an elaborate
sequence of movements to reach a particular position, we might be looking at 10 or more blocks. A
mistake in any of these blocks will follow through to all the other blocks. If we put in a sound effect after
the 5th block, students can then use that as a reference point to figure out if they need to make corrections
before or after that point.
NXT-G Specific
The LEGO MINDSTORMS system is typically used for robotics and automation applications, but it can
also make a great instrument. Built into the main NXT brick is a small speaker capable of playing different
notes and sounds
Speaker Slots
35
That bot has personality!
You can also change the default sound volume by going through the main menu setting or within the
Sound configuration panel itself. A sound level of 4 is the maximum that you can set the NXT.
Setting the default volume
Turn the NXT on
Navigate to the Settings Menu
Select the Volume Menu
Set the desired Volume
In the Volume Menu, there are 4 different sound levels (1-4). It is also possible to silence the NXT brick
by setting a sound level of 0. The MINDSTORMS system is regulated by many standards, one such being
the maximum volume permitted for a toy that is used by children. As such, the inbuilt speaker is not
extremely loud, but is enough for our purposes.
36
That bot has personality!
The Sound Block
‘Sound File’ chosen
Action: Here we can choose either a pre-loaded sound file or to play an individual tone (note). If we
choose the Sound File section, these are the following options available to us.
Control: Just leave this setting on 'Play'.
Volume: Controls the volume.
Function: This asks if we wish to repeat the sound over and over again, in most instances we will leave
this unchecked.
File: This is the sound file to use. There are many sound files built into the device already such as „Good
Morning‟, „Hooray!‟ and various buzzes, beeps and clicks.
Wait: If the 'Wait for completion' option is checked, then the program will not move on to the next block
until the sound has completely finished.
We also have the ability to play just a specific tone, rather than a pre-recorded sound file. Click on the
piano keyboard to select a note and then choose how many seconds you‟d like it to play for.
‘Tone’ chosen
Sound Block Configuration panel with „Tone‟ Action set.
37
That bot has personality!
The Display Block
The Display block has two actions that we‟ll be using the most; Image and Text. The Image action will
give you a long file list of pre-drawn images. Get your students to scroll down and find the ones that are
most appropriate for their application. The Text option allows us to specify a particular phrase of our own
choosing such as „Take me to your leader!” or “Do you have any bananas?”. Use the mouse in the
„Position‟ option to move the display around.
As with the Sound block, the Display block is an excellent way for students to keep track of where in the
program their robot is current at. Eg. Have your robot display on the screen a smiley face when it is
driving forward, and a frowning face when it is driving backwards.
‘Image’ chosen
‘Text’ chosen
38
That bot has personality!
Look out for...
One of the common problems students encounter is when placing a display block right at the very end of a
program. As there is no set time for the Display to last, a Display block as the very last instruction will
show up for a fraction of a second before the program ends. By adding in a „Wait for Time‟ block we can
leave that message up for a specific length of time.
Will only be visible
for a fraction of a
second
Ensures our ‘Display’
Block remains visible
for a specific time
39
That bot has personality!
40
Chapter 8:
How many sides?
Overview: Attach a drawing device to your robot and plot out some geometric shapes.
Project: Once on NXTopia, your robot will be required to identify interesting aspects for later analysis.
Your robot will be required to mark off an area such that a passing satellite can easily identify the item in
question. Initially you will be required to draw a square, but will then move onto other shapes and designs.
Equipment required:




1 NXT robot kit per group
1 computer per group
Large marker
Large sheet of paper
Teachers Notes
Build the drawing attachment outlined at the end of the book and attach to the front of the robot.
Students will be required to draw a square, but will then move onto other shapes and designs.
This chapter will cover the following topics:


Basic geometric shapes
Internal and external angles of a polygon
To draw a square, most students will initially decide to plot out each individual step resulting in 8 blocks (4
sides and 4 corners). But if asked how they would do a hexagon or a triangle, they can be pushed towards
understanding the need to repeat sections of code ie." Drive forward and turn, then repeat a certain
number of times". This can be achieved with the Loop block.
Photocopy and hand out Student Worksheet – How Many Sides?
41
How many sides?
NXT-G Specific
Drive Forward
Drive Forward
Turn 90°
Turn 90°
Drive Forward
Drive Forward
Turn 90°
Turn 90°
Repeat 4 times
To make our robot drive in a square, we will need to program it to go forward, turn 90 degrees, go
forward, turn 90 degrees, go forward, turn 90 degrees, go forward and do a final 90 degree turn. If we look
carefully at the program, we can see that it consists of drive forward, turn 90 degrees and repeated 4 times.
Turn 90°
Drive Forward
Driving in a square. Which is easier?
We can use the Loop block to achieve this simpler form of programming. Everything within the orange
border of the Loop block will get repeated based on the values in the configuration panel.
Loop Block: This example program will play a sound file 8 times
42
How many sides?
Theory
Cumulative error becomes a factor when using the Loop block, as errors in the turn angle can build up
every time the robot performs the turn. Eg. Let us assume the robot turns 92 degrees instead of 90
degrees. To the human eye, the first turn looks fine, but as the robot progresses around the square, the 2
degree error from each turn is accumulated into an 8 degree error at the end of the square.
When progressing to the octagon, it is important to realise that the angle the robot must turn is the
external, or exterior angle of the polygon.
The following equations can be used to calculate the internal and external angles of a polygon.
Shape
Number of sides
Internal angle
External angle
Turn Angle required by
the robot*
Octagon
8
135°
45°
135°
Hexagon
6
120°
60°
180°
Triangle
3
60°
120°
360°
*Don't forget that the angle required by the robot, is not the same angle required by the wheel. If the
distance between the wheels has changed slightly, then the actual number will be slightly higher or lower
than the one indicated in the table.
Refer back to DomaBot Basics to calculate the required durations for the sides of each shape.
Look out for...
The critical component in this challenge is the angle. A robot with the correct turn will arrive exactly back
where it started. Mark the starting point with a strip of tape on the floor and measure how close each
robot finishes.
With this particular design, the marker is not located at the point from which the centre of the robot will
pivot. This will result in the follow shape.
43
How many sides?
As the marker is located in front of the wheels, the corners
will not be perfectly square as indicated in this diagram
Extension Activity
Modifying the mechanical structure of the robot is a good extension activity to run. Have the students
change the design of the robot so that it will draw precise corners. This is achieved by locating the marker
pen exactly in between the wheels. When the robot turns on the spot, the pen will not travel any distance,
and will just rotate over the corner point.
Marker pen needs to be located exactly in between the axis of rotation
of the wheels to ensure sharp corners.
44
How many sides?
Example Program
Make your Robot drive in a square
45
How many sides?
46
Chapter 9:
Help! I'm Stuck
Overview: Equip your robot with a bump sensor to help it navigate on NXTopia.
Project: Whilst on NXTpoia, your robot will undoubtedly come up against some terrain that is too difficult
for the robot to navigate. NASA is worried about a particular chasm near the drop zone where the robot
could conceivably get trapped. They have asked that you demonstrate your robots ability to detect such an
obstacle and navigate out of the chasm.
Follow the instructions in Building Instructions to construct the touch sensor attachment. Ensure the
Touch Sensor cable is connected to Port 1 on the NXT brick.
Equipment required:



1 NXT robot kit per group
1 computer per group
Chasm made from books, overturned tables or cardboard boxes
Teachers Notes
Photocopy and hand out Student Worksheet – Help, I‟m Stuck. This chapter will introduce students to
external sensors on the robot. These sensors can be used to gather information about the environment the
robot is in, and with this information the robot can perform informed choices.
Topics covered include



Complex system
Sensing and measuring conditions
Conditional statements
47
Help! I'm Stuck
Start driving forward
Wait until you bump into something
Stop your motors
Back up slightly
Turn around slightly
Flowchart outlining possible program flow to solve the Help! I’m stuck challenge
NXT-G Specific
To do this project, we will need to introduce a new set of commands, the Wait blocks. These blocks allow
us to use the various sensors to control the movement of the motors. The first block we will implement is
the Wait for Touch block.
Wait for Touch Block: Wait until the touch sensor has
been pressed before moving to the next block
It is best to think of this block as a description. “Wait at this block until the button on Port 1 is pushed.
Once the button has been pushed, continue on to the next block.”
48
Help! I'm Stuck
This activity will also introduce us to another configuration panel parameter within the Move block. We
do not want our robot to only spin for a set number of revolutions, we want it to spin indefinitely until a
bump is felt. To make this possible we will use the 'unlimited' option of the duration configuration panel.
You will notice a little infinity symbol (∞) appear on the block itself.
Turn motors B and C on at a power level of 75 percent,
unlimited duration and move directly to the next block.
The motor will now continue to spin until it is explicitly turned off by another block.
A good way to think of this is to use the analogy of our lights in our bedroom. If we walk into our room
and turn the light switch on, the lights go on. If we now walk out of the room, the lights are still on. If we
want the lights to turn off, we must explicitly turn them off. The same is true for motors, if we turn them
on with the unlimited option, later on in our program we must use another block to turn them off.
We will be using the unlimited function of the move block for this project. This property allows us to
continue driving until we are told otherwise. We may have to drive forward half a rotation it may be 10
rotations before we encounter an obstacle. We must wait until the touch sensor has been triggered before
we perform any different movements of the robot.
Theory
Senses are what makes a robot a robot, and not a glorified remote control car. With the information
gathered by these sensors, the robot can perform an informed decision as to its next movement.
Information is recorded from a physical property (ie getting bumped or registering a particular light level)
and converted into a stream of data that is meaningful to the brains of the robot.
49
Help! I'm Stuck
A conditional statement makes decisions on the flow of the program based on external information. In
this challenge, we have asked our robot to drive forward continuously until a particular condition is met.
In this case it is when the bump sensor detects a wall. Once this condition is met, the robot can then
decide to perform additional actions to deal with the information it has received, namely backing up and
turning away.
Look out for...
Students will find that if they just try and turn when they detect a wall, they will get caught up against the
wall. A more robust solution will require the robot to back up a small distance before rotating.
The chasm can be as simple as a set of books piled up, or can be built and painted by the students as part
of the creative design component of their syllabus.
Simple chasm made from NXT storage boxes
50
Help! I'm Stuck
Example program
This is a possible solution to the final activity on the worksheet
51
Help! I'm Stuck
52
Chapter 10:
Help! I'm (still) stuck
Project: Swap the bump sensor for the Ultrasonic sensor.
Scenario: NASA are happy with your bumper, but are concerned that the physical impact with the chasm
walls will dislodge rocks sitting above. Modify your robot to include the Ultrasonic Sensor and run the
same program, but this time recognising the walls before you touch them.
Remove the Touch Sensor attachment and connect a sensor cable from the Ultrasonic Sensor to Port 4 on
the NXT brick.
Ensure the Ultrasonic Sensor
is connected to Port 4
53
Help! I'm (still) stuck
Teachers Notes
Photocopy and handout Student Worksheet – Help, I‟m (still) Stuck.
Students will now need to remove the Touch Sensor attachment from their robot. Make the cables are
correctly inserted. As will be explained in the theory below, the values obtained by the Ultrasonic Sensor is
highly dependent on the surface of the object that is being detected.
The terminology of Distance and Ultrasonic are often mistakenly interchanged. The correct definition is
that the Ultrasonic Sensor is used to measure distance. Within the NXT-G development environment, we
will often come across blocks such as Wait for Distance, which uses the Ultrasonic sensor to return a
distance reading.
This challenge is very similar to the original Help! I‟m Stuck challenge and as such requires only a minor
modification to the flowchart.
Start driving forward
Wait until you sense the walls
Stop your motors
Back up slightly
Turn around slightly
Flowchart outlining possible program flow to solve the Help! I’m (still) stuck challenge
54
Help! I'm (still) stuck
NXT-G Specific
Students will need to swap the Wait for Touch block for the Wait for Distance block.
To see what distance values the robot is sensing, we will need to use the view menu on our NXT. The
view menu will allow the students to see what values the robot is sensing for each sensor.
Turn the NXT on, you should have the following menu screen. (your robot may not be named „Damien‟)
Using the grey left and right arrow button on the NXT, navigate to the „View‟ menu item. Press the
orange „select‟ button to choose the „View‟ menu.
55
Help! I'm (still) stuck
Again use the grey left and right arrow buttons to find the „Ultrasonic cm‟ or „Ultrasonic inch‟ menu. Press
the orange button to select this menu.
OR
Choose the correct port that the sensor is plugged into. This will be Port 4 if you have followed the
DomaBot building instructions.
The screen will now display a reading for how far away the nearest object is thought to be.
56
Help! I'm (still) stuck
Theory
The Ultrasonic sensor employs the use of ultrasonic range finding to determine to distance to an object.
Ultrasonic sensors, or SONAR (SOund Navigation And Ranging) sensors emit a very high frequency
soundwave from one of the two openings in the sensor. This soundwave is typically 40KHz, far above
what a human ear can detect. This soundwave travels through the air, and bounces off an object with the
echo returning to the other opening on the sensor. By measuring how long it has taken for the sound to
travel out to the object and return again, the sensor can determine how far away the object is.
Soundwave reflection
Object
Ultrasonic Sensor
Ultrasonic soundwave
The robot is able to determine the distance to the object by timing
how long it takes a reflected soundwave to return to the sensor.
The reading that the Ultrasonic sensor will display is dependent on the surface off which the ultrasonic
waveform is reflected. Smooth, perpendicular surfaces give accurate readings, whereas irregular surfaces,
(such as hands, other robots, angled walls etc) may give different results. The key here is to do plenty of
testing.
Look out for...
Students must also remember that the distance measure of the sensor if taken from the front of the sensor,
which may not be the front of the robot. Make sure they take into account any attachment sitting in front
of the robot.
Students will find that the readings they get from their sensor do not match what they are able to measure
with a ruler. This is a result of the ultrasonic waveform bouncing off the intended object at unusual angles.
If the cable has not been correctly connected on the robot, or it has been connected to the wrong port, you
will see the following screen when trying to view the Ultrasonic sensor readings.
57
Help! I'm (still) stuck
Cable not correctly plugged in, cable plugged into the wrong sensor port
or nearest object is too far away to be seen.
Example Program
See the example programs for Help! I‟m Stuck, and substitute in the Wait for Distance block in place of
the Wait for Touch block.
Wait for Distance Block: Wait at this block until the distance measured by the Ultrasonic sensor in Port 4
gives a reading of less than 20 cm. Once this condition has been met, proceed directly to the next block.
58
Chapter 11:
Stay Away from the Edge
Overview: Use the light sensor to remain on the table.
Project: Another challenge the robot might face is safe navigation along a ridge line. Get too close and
over you go. NASA has asked that you prove your robot is capable of staying away from the edge of a
cliff.
Equipment required:



1 NXT robot kit per group
1 computer per group
Table top
Teachers Notes
Follow the instructions in Building Instructions, to attach the light sensor attachment to the robot.
The algorithm for this particular challenge is very similar to the previous challenge, but using the light
sensor in place of either the touch or Ultrasonic sensor. The light sensor is arrange such that it is looking
straight down at the table. This will return a high reading whilst on the table, and will transition to a
significantly lower reading once the light sensor has gone over the edge of the table. Once this change in
light reading has been observed, the robot can then stop the motors, preventing it from going over the
edge of the table.
59
Stay Away from the Edge
Start driving forward
Wait until you sense the edge of the desk
Stop your motors
Back up slightly
Turn around slightly
Flowchart outlining possible program flow to solve the
Stay Away from the Edge challenge
NXT-G Specific
This challenge requires the use of the Light Sensor block.
The Wait for Light block operates in the same fashion as the Wait for Touch and Wait for Distance
blocks. The block can be configured to wait for either the situation where the light levels are increasing or
when the light levels are decreasing.
60
Stay Away from the Edge
Theory
The threshold is a term that is used to differentiate between two different states. All the information that the
NXT receives is converted into numbers so it is understandable by the robot. By selecting a threshold, it is
possible for the robot to decide if it is either 'above' or 'below' this threshold.
Take for example the robot driving on a white piece of paper towards a black line. As the sensor passes
over the black line, the light sensor readings will not just change from a high number to a low number,
instead it will side down the readings until it reaches the value for solid black. These 'in between' numbers
are still valid readings and the robot must decide if they are either 'white' or 'black'; it has no sense of 'grey'.
Light sensor readings
White reading
Above
Threshold
Threshold
Robot thinks
it is on white
Below
Threshold
Black reading
Robot thinks
it is on Black
Light sensor goes from white  black
Let us assume that when on the white paper, the robot's light sensor gives us a reading of 50. When on the
black, it gives a reading of 30. What we need to decide is, at what number (our threshold) does our robot
go from seeing white to seeing black? The safest number to choose is halfway in between, 40. If our
sensor reads above 40, it is a very good chance that we are on white. If we are below 40, then chances are
we are on black. This number can be push a little higher or lower and this will cause the robot to react a
little faster or a little slower to the black line.
61
Stay Away from the Edge
Look out for...
Choosing a threshold value works best when there is considerable contrast between the table and the floor.
Good: White shiny table with a dark carpet. This setup will give high readings for the table and low
readings for when the sensor is over the edge of the desk.
Not so Good: White table over polished wood with lots of sunlight in the room. The sunlight will bounce
off the shiny floor and straight into the sensor. It is possible in some circumstances to have the edge of
the desk brighter than the desk itself. If necessary, place a white sheet over the table for added contrast.
The major problems the students will encounter are as follows
Problem: Robot does not react to the edge of the table.


Possible Solution: Threshold value is not a number in between the light and dark readings. Take
some new readings and calculate a new threshold number
Possible Solution: If the students hold their hands too close to the robot in anticipation of
catching, the robot will believe the hands are an extension of the desk and will continue to drive.
Problem: Robot only drives forward a small amount before stopping, although the program still appears to
be running.


Possible Solution: The first move block has not be set to unlimited. What has most likely occurred
is that the robot has driven forward 1 rotation as directed and is now sitting still waiting for the
light sensor value to go low.
Check to ensure the Wait for Light is configured for „less than‟. If it is configured for „greater
than‟, the robot takes a reading of the table, realises it is already greater than the threshold and
stops immediately.
Problem: Robot recognises the edge but falls off as it turns.

Possible Solution: Back the robot up further before attempting to turn around.
62
Stay Away from the Edge
Example Program
This program is the same as 'Help, I'm stuck', but uses the Wait for Light block instead of the other Wait
blocks.
This number will be dependent on the
light conditions in your classroom.
Extension Activities
This particular challenge can be used anywhere there are two contrasting colours present. These activities
are all appropriate.


White masking tape „prison‟ on a dark carpet
Black electrical tape „maze‟ on white tiles
63
Stay Away from the Edge
64
Chapter 12:
Did you hear that?
Overview: Use the Sound sensor to react to noise.
Project: The possibility of alien life forms present on NXTopia is quite high. NASA are concerned that
they might be hiding and that the robot will not see them unless it can hear them approaching. Build a
robot that can react to loud sounds.
Remove the Light Sensor attachment from the previous challenge. Connect the Sound Sensor to Port 2 on
the NXT brick.
Ensure the Sound Sensor
is connected to Port 2
65
Did you hear that?
Equipment required:


1 NXT robot kit per group
1 computer per group
Teachers Notes
Students will have to use the 'view' menu item to take different readings of loud and quiet sounds. A short
sharp clap, close to the microphone will likely take the sensor to its upper threshold of 100. When
choosing a threshold, keep it quite high (over 85) so that the robot will only respond to a noise that is
generated close to the robots sensor. When you have a class of many robots, it can get quite noisy!
Theory
It is important to realise that sound is quite a slow phenomenon when compared to light or touch. The
sound of a clap of the hands can last quite a long time.
The following graph shows the sensor readings for a clap.
66
Did you hear that?
There is very little reading to start with, and then the sensor rapidly climbs just after 0.5 second. The
sensor maxes out at a reading of 100 for approximately 0.1 of a second before it falls again.
This can become problematic when using the sound sensor to differentiate between different claps.
Take the following program, where we want the robot to start moving with a clap, and stop moving with a
clap.
Clap to start moving, clap to stop moving. Will not work!
This particular implementation will not work, as the first clap will trigger the first Wait for Sound block, at
which point the robot will turn the motors on with an unlimited duration. It will then start listening for the
second clap, which in fact is still the first clap as it has not had enough time to die away. Thus this one
clap will trigger both Wait for Sound blocks.
There are two possible solutions to get around this issue;
Wait for 0.2 seconds after each clap to give the clap time to fade away.
Wait for 0.2 seconds to let the
sound level of the initial clap fade
away
Wait for the measured volume to get loud, and then wait for it to get soft before turning on any motors.
Wait for the sound to go
‘greater than’ the threshold
67
Wait for the sound to go
‘less than’ the threshold
Did you hear that?
Look out for....
In a large group with many students, you will find that it is easy for other groups to accidentally trigger
another group‟s robot. Wooden floors tend to transmit sound waves very efficiently, with a heavy footstep
at one end of the classroom being recognised by a robot at the other end of the room.
Be aware that the motors also make noise, and while it is not loud enough to be a concern for this
particular challenge, if the students wish to trigger on quieter sounds, they must take into account this extra
noise.
Example programs
Drive forward until you hear a sound and then stop for 2 seconds and slowly turn around for 360 degrees
of the robot.
68
Did you hear that?
69
Chapter 13:
Mini-Golf
Overview: Build and program a robot to play a round of mini-golf.
Project: Students use the skills they have learnt from previous weeks to build a robot that can play a game
of mini golf.
Equipment required:




1 NXT robot kit per group
1 computer per group
Red and Blue NXT ball
Putting green (see below)
Set up:
A putting green is required with a set cup location. This could be constructed with a sheet of MDF or
plywood. Use a hole saw to cut a 50mm / 2 inch hole in the board to act as the golf cup. Sand down any
rough edges.
Print out or paint a bullseye pattern using the following dimensions as a guideline.




Centre hole: 5cm / 2 inch
1st ring: 10cm / 4 inch
2nd ring: 20cm / 6 inch
3rd ring: 30cm / 10 inch
70
Mini-Golf
D
A
B
1800mm / 6‟
C
Start
1200mm / 4‟
71
Mini-Golf
Game Play:
Robot is placed in the starting box.
A standard golf ball is placed in either position A, B, C or D.
Competitor presses the run button and allows the robot to head off.
There are 5 rounds, with the golf ball placed is a different location for each round.
Robots have 1 minutes in which to strike the ball. They may restart as many times as they wish within this
time until the ball is struck. Once struck, the final resting position of the ball determines the points scored
for the round.
The ball should be struck, not pushed, towards the cup.
Scoring





50 points for getting it in the hole
30 points for closest ring
20 points for the next ring
10 points for the outer ring
5 points for making contact with the ball
Teachers Notes
The students will need to discover that they need some sort of 'bumper' on the front to ensure accurate
and repeatable test runs. Something resembling a slight 'v' shape will probably work best as it will funnel
the ball towards the centre of the robot.
Rounds 1 and 2 allow them to get points on the board. Hitting the ball as hard as possible should be
naturally discouraged as if they miss the cup, they do not want it rolling completely off the bullseye.
Rounds 3,4 and 5 should promote planning. Ideally they should draw on a piece of paper what path their
robot will take, and what movements they need to accomplish it.
Extension Activities
Is it possible to knock in all 4 golf ball locations from a single program? ie. No taking the robot back to the
starting position to reset.
Research other mini-golf layouts and replicate some of the interactive elements (windmills, moving
characters etc)
72
Mini-Golf
73
Chapter 14:
Dancing Robots
Overview: Program your robot to perform their own dance routine
Project: Students will synchronise multiple robot to dance and move in time with the music. The focus
for this challenge is the integration and coordination of multiple robots.
Equipment required:




1 NXT robot kit per group
1 computer per group
Music player
Decorations (straws / pipe cleaners etc)
Teachers Notes
Students can team up with other groups to create dancing partners or they can perform a solo dance.
Choose a piece of music approximately 60 seconds in length
With either a stopwatch or software program, have the students map out the time it takes for significant
sections of the music. Once they have the length of times required, they can start programming their
robots to fill each time bracket. Test often with the music to ensure the robots movements synchronise
with the timing of the music.
When they are happy with their performance, have the student dress up their robots with decorations such
as:





Pipe cleaners
Coloured paper
Bobbly eyes
Sequins
Feathers
74
Dancing Robots
Look out for...
Here are a few tips to make the students robot presentation more visually appealing. The key concept is
timing with the music. An entertaining robot dance to watch has the robots changing their movements in
time with the music.
Alternate the robots movements between fast and slow motions. The more variety and contrast there is in
the performance, the better it is to watch. Do some research into the RoboCup Junior Competition.
There is a division devoted to dancing robots with many excellent examples available. Look at the
„Resources‟ section of the Domabotics website for videos of dancing robots.
The following table is very useful in planning out robots dance sequences.
Song Name:
‘Robots Rock’
Artist:
The Amazing Androids
Section
Time
Description
Intended robot movement
Intro
0 sec – 8 sec
Slow and steady.
Just Slow rocking from side to side in time
drums and bass guitar
with drums
1st Verse
8 sec – 15 sec
Guitars come in and speed Looped forward and backwards
gets faster
movements, slightly faster than intro
Chorus
15 sec – 23 sec
Steady rhythm, quite fast
Robots even faster now, doing full
turns on the sopt
2nd verse
...
...
...
Chorus
If you are finding resistance from the students to the concept of „dancing‟ robots, the same activity can be
performed but with a different theme



Robotic Marching Band
Aerial stunt pilots (eg. The Flying Roulettes)
Synchronised swimming
75
Dancing Robots
Keep the movements relatively short. A robot that drives forward for 1 second is actually quite a long
time. Keep dance movements short and repeat often. Encourage the students to use up time with the
loop command. ie.
[ (FORWARD 0.2 seconds, BACKWARD 0.5 seconds, turn clockwise 0.3 second) repeat 5 times ]
This particular sequence would take up 5 seconds with only 4 blocks used.
76
Dancing Robots
Extension Activity
Create a music video of your robot in action. Take multiple videos of the robots in action. Using movie
editing software, cut the different segments together. Add some special effect and the backing music and
show it to the class.
77
Chapter 15:
Robot Wave
Overview: Create your own robotic supporters for the local sporting match
Project: Students will synchronise multiple robot to perform a Robot wave.
Equipment required:


1 NXT robot kit per group
1 computer per group
Teachers Notes
Students will line their robots up, and on starting, each of the robots will move forward and then move
backwards. Individually this program is quite unexciting, but when teamed up with multiple robots, the
effect can be very appealing.
The emphasis for this challenge is the coordination of several robots. The program required to do the
basic motion is quite straight forward, but the success of the robots is dependent on all robots running at
the correct time.
A Robot wave is created in a sporting stadium when a group of people stand up and sit down again. The
people immediately to their side do the same and the „wave‟ progresses around the stadium.
The basic program to implement a Robot wave is as follows.



Wait for a set period of time
Drive forward, 75% power for 1 second
Drive backward, 75% power for 1 second
The key component is how long each robot is required to wait before heading off. The first
implementation should have Robot 1 wait for 0.5 seconds, before driving forward. Robot 2 will wait for 1
second, Robot 3 will wait for 1.5 seconds and so on down the line.
78
Robot Wave
All Robots lined up
First Robot heads off
Second Robot heads off
Third Robot heads off
etc...
79
Robot Wave
When using a 0.5 second delay between each robot, the required „wait‟ time is half the group number. eg.
Group 5 will need to wait for 2.5 seconds.
Once the initial wave has been mastered, it is possible to extend the range of motions that each robot
performs. Rather than the basic „Drive forward, Drive backward‟, try these different combinations. Leave
it to the group to devise their own choreography.




Forward 1 second fast, Backward 1 second slow
Forward 1 second, Backward 2 second, Forward 1 second
Forward 1 second, Backward 2 second, Forward 1 second, Loop the whole procedure 4 times
Arrange the robots in a circle rather than a straight line
Example Program
This program describes the basic Robot wave program
This number will be
dependent on the robots
order in the line
80
Robot Wave
Extension Activities
Can you hear me?
The trickiest part of the Robot Wave challenge is coordinating multiple robot to all run at the same time.
This can be bypassed by using the Sound sensor to trigger the robots.
By entering in a relatively high (80+) number into the threshold, the robots can be triggered with a clap or
a stamp of the feet. The Wait for Time block will need to be retained, otherwise all the robots will move
forward in a line once the sound level has been exceeded.
Up and Back
Have the wave progress up the line, and then come back down the line to the starting robot. This will
require some careful planning to ensure each robot knows how long to wait before performing their 2nd
wave.
Cheerleaders
Add the 3rd motor to the robot to create some arms with pom-poms. Run the Robot wave using these
pom-poms as well.
81
Chapter 16:
Robot Butler
Overview: Build a robot that can assist the elderly and disabled
Project: Robots in the household are quickly becoming commonplace, with personal assistance robots
widely regarded to become the most prevalent in the near future. Build a robot that can retrieve a drink for
someone who is confined to bed.
Teachers Notes
This challenge can be as open ended as required. There is no extra content that is required to be taught,
rather the challenge is in integrating the various systems and programming knowledge that has already been
learnt.
A typical scenario is as follows.
Your great Aunt Winnifred is confined to her bed due to her bad ankle. You are required to build a robot that
can fetch a glass of water from the kitchen and return it to her bedside.
It must navigate from the bedroom, out the door and down the hallway to the kitchen on the left hand side.
Once the robot is in the kitchen, it must drive up to within 5cm / 2” of the shelf. A drink is placed on the top
of the robot and it must return to the bedroom.
For this challenge student will be required to accurately plan a path out of the bedroom and down to the
kitchen using the Move block. Once there, they then use the Ultrasonic sensor to approach the shelf.
Students will need to build a platform on which to hold the cup of water (empty of course). This platform
could use the touch sensor to tell when a weight has been placed on the robot. Once the cup is on the
robot, it must turn around and return to the bedroom.
This can be as open ended as desired and the scenario can be tailored to suit any ability or theme within the
classroom.
82
Variations
Race Car
The robot must navigate a race car track, but also stop at the pit stop for fuel and wait until other cars to
leave the pit stop before exiting.
Traffic Lights
Robot must traverse down a suburban street and stop for traffic lights and pedestrians.
Rubbish Disposal
Robots drive around a table top and when they find a piece of trash, they take it to the edge of the table
and dispose of it over the side.
83
As seen on TV!
AS SEEN ON
TV!
Chapter 17:
As seen on TV!
Overview: Create a multimedia presentation to market and sell your robot.
Project: NASA have decided on using your design to fly to NXTopia. As a result of the associated
publicity, many other people want to buy their own version of the robot. Come up with a marketing
promotion to sell your robot.
Equipment required:


1 NXT robot kit per group
1 computer per group
Teachers Notes
Students should think of their group as a „company‟ that must pitch a „product‟ (in this case their robot) to
the general public. It is left up to the teacher to decide the final format, but any of the following media
types would be appropriate.






School Newspaper article
Video commercial
PowerPoint Presentation
Poster presentation
Website
Oral Presentation
Students can have considerable leeway with the creative claims of their product as long as they are feasible.
Good – Our robot can be charge by solar panels
Bad – Our robot can fly just by driving very fast!
84
Issue that will need to be addressed include:






Form – What does it look like?
Function – What can it do?
How does it move?
How does it sense its environment?
How much will it cost?
Are there any special features?
85
Meet your adoring public!
Chapter 18:
Meet your adoring public!
Overview: After your glorious mission, your robot will want to meet with its fans and supporters
Project: Program your robot to respond in a positive way when somebody gets close. Use the Move,
Sound and Display blocks to convey a feeling of happiness.
Equipment required:


1 NXT robot kit per group
1 computer per group
Teacher Notes
This project can be built up in stages. Initially just have the student‟s robot respond when somebody walks
up to it. This is similar to the “Help! I‟m (still) stuck” activity in the use of the Ultrasonic Sensor. But in
this case, rather than waiting for the robot to drive up to an object, it will wait for an object to approach
itself. Once the robot can accurately identify an object, students can then let their creative energies flow to
have their robot respond with a feeling of happiness. „Happiness‟ is a very subjective measure and it is
always interesting to see what interpretation the students come up with.
Example Program
This program waits until somebody approaches within 30 cm (12 inches), says „Good morning!” and then
does a little wiggle. The whole time it has a smiley face on the display.
86
87
Meet your adoring public!
Extension Activity
The natural extension to this project is to now have the robot act „sad‟ when the person walks away. To
implement this, you will again need a „Wait for Distance‟ block, but this time the robot is waiting for a
Greater Than condition to occur as the person walks away. It is advisable that you increase the threshold
distance as your robot may have moved from its initial starting position when it does its „happy‟
movements. Sad actions generally include sad faces, low notes and slow movements.
Add a third motor to the „A‟ port and connect a flag for a true parade loving robot!
88
Chapter 19:
Student Worksheets
In this section you will find all the student worksheets referred to in the preceding chapters. The owner of
this book has photocopy permission to reproduce as many copies of these worksheets as is required by
their class.
89
Student Worksheet – What is a Robot?
When you hear the word 'robot' some famous movie robots spring to mind. Robots in real life however
are not yet up to the standard of their movie counterparts.
Robots are becoming more prevalent in today's society. There are used in high level applications such as
space exploration right through to commercial vacuuming robots found in everyday households. You are
required to do a research assignment on robotics in general and to focus on one robot in particular.
Robots come in many different shapes and sizes and are often tailored to meet a particular need or action.
Assessment
Create a report on robotics. Your teacher will tell you the format of the report. The following questions
will need to be addressed in your work.





What is a robot?
Why do we have robots?
Name some different types of robots?
What are the main components of a robot?
Where did the term 'Robot' come from?
Pick one robot and elaborate on it. You must have your robot choice approved by your teacher before you
start your research. You will need to include the following information in your report:
Sensors - What information does it take in? (e.g. Sound, distance etc)
Software - What does it do? (e.g. Vacuum floors, explore space)
Mechanical - What materials is it made out of? How does it move? (e.g. motors, arms and metal frames)
Robot Chosen ________________________
Due Date__________________
Presentation Type______________________
Page / Slide limit____________
Student Worksheet - Flowcharting
All robots need to have programs to make them run. The easiest way to start a program is to firstly have a
plan. This plan consists of a flowchart of small steps that make up the entire program. Each step is simple
enough that the robot can perform it without too much effort.
Task: Using the blank flowchart below, plan out your daily morning routine, from when you wake up until
you get to school.
Wake up
Arrive at
School
Student Worksheet – DomaBot Basics
Group Name______________________
Group Members_________________________
Overview: NASA is in the market for a new planetary rover to explore the recently discover planet
NXTopia. You are required to design and construct a robot that is capable of following a set of
commands to explore the planet's surface. Before the robot is deployed, it must be extensively tested to
ensure it will perform as expected. You can't fly a technician to NXTopia to reboot the robot!
Before we send our robot into space, we must first test it thoroughly here on earth. Run the following
experiments and observe how your robot behaves. Do not move to the next experiment until your teacher
has seen your current experiment.
Drive Forward for 90° of the wheels
How far did your robot travel?
_________________
Drive Forward for 0.25 rotations of the wheels
How far did your robot travel?
_________________
What is the circumference of the robots wheel?
(hint: you will need to measure the diameter of the wheel)
_________________
How far will the robot drive if the wheels turn 3 rotations?
_________________
Program your robot to move 3 rotations and measure how far it goes.
Does it go as far as you expected?
Drive Forward 540° slow, then 540° back as fast as possible
Turn the robot around 180°
What happened? How far did your robot turn if you type in 180°?
_________________
How much Duration does the wheel need for the robot to turn 180°?
(hint: keep experimenting until it is perfect!)
_________________
Drive forward for 500mm (OR 20 inches), turn around 180° and drive back to where you started
How much duration do you need to go forward 500mm (20 inches)?
(hint: Have a look at the circumference of your wheel,
this will tell you how far your robot goes in 1 rotation)
_____________
Make your robot drive in a 'figure of 8'
(hint: draw a diagram first in the space below before you start programming. Don't forget to mark your
starting point!)
Student Worksheet – How far?
Group Name______________________
Group Members_________________________
Overview: In the initial construction of the robot the travelling characteristics are required. After
characterising the properties, NASA have asked that you use your data to make predictions about the
distance your robot will travel given specific time constraints.
Your group will be assigned a random power level to be assessed. Power Level Assigned ____________
For this experiment you will need to measure how far the robot travels for different time values (eg. 1
second, 2 seconds, 3.5 seconds etc). The more data you gather, the more accurate your graph will be.
Plot the results either on the graph below or in a graphing software package.
(Hint: you will need to know the smallest and largest times you tested for, as well as the smallest and largest
distances so that you can determine the horizontal and vertical axis scales)
Once you have plotted your data, can you see a relationship between the time taken and the distance
travelled?
By looking at the graph, can you determine how many seconds
your robot would need to travel exactly 30com (12 inches)?
_____________ seconds
How about 1.5m (59 inches)?
_____________ seconds
Your teacher will assign you a test distance. How long does your robot need to travel this particular
distance?
Test Distance =
_______________
Time required = _____________ seconds
Distance Travelled
Distance Travelled vs Time Taken
Time Taken
Student Worksheet – How fast?
Group Name______________________
Group Members_________________________
Overview: To accurately be able to command the robot, you need to understand how fast it can go and
what properties may change its performance. NASA have requested a detailed report, supported by data
that you have gathered from your robot.
Make your robot drive forward for 5 rotations at 50% power
How long did it take to go 5 rotations?
______________ sec
What about 10% power?
______________ sec
70% power?
______________ sec
Fill in the time taken to complete 5 rotations on this table and plot your average on the graph
Power
Level (%)
10
20
30
40
50
60
70
80
90
100
Run 1
Run 2
Run 3
Run 4
Run 5
Average
Draw a line of best fit through the data you have taken.
Based on this data, make a prediction as to how long it will take to
do 5 rotations at 65% power.
_____________ seconds
Mark your prediction on your graph in a different colour. Program your robot and see what happens.
How close were you?
Let us now convert this time taken into a speed.
How far does 5 rotations of the wheel take us?
_____________
Now convert each of these times and distances into a speed for each different power level. Fill in your
answers in the table below.
Power Level (%)
Time for 5 rotations
Speed (m/sec OR inches/sec)
10
20
30
40
50
60
70
80
90
100
Plot the speed of your robot against the power level on the following graph.
NASA have indicated that in some parts of NXTopia, the loose sand will make it difficult to drive quickly.
They have calculated that the robot cannot exceed a maximum speed of 25 mm/s OR 10 inches/sec.
What power level is required to meet this speed?
__________________ % power level
Mark the speed on your graph in a different colour. Program your robot to travel for 10 seconds and
check to make sure your robot stays within the guidelines.
What would happen if we were to run the same experiment on carpet?
What was the most difficult part of this challenge? __________________________
How did you go about solving it? ______________________________________
Student worksheet – How Many Sides?
Group Name______________________
Group Members_________________________
Overview: Once on NXTopia, your robot will be required to identify interesting aspects for later analysis.
Your robot will be required to mark off an area such that a passing satellite can easily identify the item in
question. Initially you will be required to draw a square, but will then move onto other shapes and designs.
Build the drawing attachment and fix it to your robot and program your robot drive in a square, with each
side 500mm (20") in length.
How many sides does a square have?
_______________
How many angles?
_______________
How many degrees in each angle?
_______________
Could you use the loop block to make the program simpler?
Fill in the following table for other common shape
Shape
Number of
sides
Internal
angle
External
angle
Turn Angle required by
the robot
Octagon
Hexagon
Triangle
What was the most difficult part of this challenge? __________________________
How did you go about solving it? ______________________________________
Student Worksheet – Help! I’m Stuck
Group Name______________________
Group Members_________________________
Overview: Whilst on NXTpoia, your robot will undoubtedly come up against some terrains that are too
difficult for the robot to navigate. NASA is worried about a particular chasm near the drop zone where
the robot could conceivably get trapped. They have asked that you demonstrate your robots ability to
detect such an obstacle and navigate out of the chasm.
Build a bumper to be attached to the front of your robot.
There are several progressive steps we would like to make in order to solve this problem. Each program
should be done individually and demonstrated to a teacher before moving on.
We would like our robot to drive forward until it encounters an obstacle.




Drive until object is detected, then stop.
Shout 'ouch!' when you hit an object
Turn around when you hit the object.
Repeat this action until you find your way out of the chasm
What was the most difficult part of this challenge? __________________________
How did you go about solving it? ______________________________________
Student Worksheet – Help! I’m (still) Stuck
Group Name______________________
Group Members_________________________
Overview: NASA are happy with your bumper, but are concerned that the physical impact with the chasm
walls will dislodge rocks sitting above. Modify your robot to include the Ultrasonic Sensor and run the
same program, but this time recognising the walls before you touch them.
Connect the Ultrasonic Sensor to your robot.
Use the „View‟ menu on your robot to see what types of readings you get with the Distance Sensor
View  Ultrasonic (cm OR inch)  Port 4
There are several progressive steps we would like to make in order to solve this problem. Each program
should be done individually and demonstrated to a teacher before moving on.
We would like our robot to drive forward until it encounters an obstacle.




Drive until object is detected, then stop.
Shout 'hello!' when you are close to an object
Turn around when you are close to the object.
Repeat this action until you find your way out of the chasm
What was the most difficult part of this challenge? __________________________
How did you go about solving it? ______________________________________
Student Worksheet – Stay Away from the Edge
Group Name______________________
Group Members_________________________
Overview: Another challenge the robot might face is safe navigation along a ridge line. Get too close and
over you go. NASA has asked that you prove your robot is capable of staying away from the edge of a
cliff.
Build a light sensor attachment for your robot.
We will need to take some readings to determine what values your robot reads for the table and the edge of
the table.
View  reflected light  Port 3
What value do you get when your robot is on the desk?
_________________
What value do you get when the light sensor is over the edge of the desk?
(hint: keep your hands and legs out of the way)
________________
What is your threshold number?
_________________
There are several progressive steps we would like to make in order to solve this problem. Each program
should be done individually and demonstrated to your teacher before moving on.
We would like our robot to drive forward until it recognises the edge of the desk. Get ready to catch it just
in case!




Drive until the edge is detected then stop.
Shout 'whoops!' when you get to the edge.
Turn around when you reach the edge.
Repeat this action staying away from the edge of the chasm
What was the most difficult part of this challenge? __________________________
How did you go about solving it? ______________________________________
Student Worksheet – Did you Hear That?
Group Name______________________
Group Members_________________________
Overview: The possibility of alien life forms present on NXTopia is quite high. NASA are concerned that
they might be hiding and that the robot will not see them unless it can hear them approaching. Build a
robot that can react to loud sounds.
We will need to take some readings to determine what values your robot reads for different noises.
View  Sound dB  Port 2
How loud is a clap?
___________________________
How loud is silence?
___________________________
Like previous challenges, we will be breaking this one down into small manageable programs


Drive forward until you hear a sound and then stop
Once the sound is heard, stop for 2 seconds and slowly turn around for 360 degrees of the robot.
How much duration does the wheel require to enable your robot to turn around 360 degrees? _____
We will now use 2 sensors to locate our alien.



Drive forward until you hear a loud sound.
Turn around slowly until you see an object within 30 cm (12")
When you see your alien, stop and say hello
What was the most difficult part of this challenge? __________________________
How did you go about solving it? ______________________________________
Student Worksheet - MiniGolf Score Sheet
Points
Group
Name
Total
Round 1
Round 2
Round 3
Round 4
Round 5
Position
A
Position
A
Position
B
Position
C
Position
D
Student Worksheet – Dancing Robots
Group Name______________________
Artist:
Section
Group Members_________________________
Song Name:
Time
Description
Intended robot movement
Student Worksheet – As seen on TV!
Overview: NASA decided on using your design to fly to NXTopia. As a result of the associated publicity,
many other people want to buy their own version of the robot. Come up with a marketing promotion to
sell your robot.
Your presentation may consist of one or more of the following media formats as notated by your teacher






School Newspaper article
Video commercial
PowerPoint Presentation
Poster presentation
Website
Oral Presentation
Be sure to include the following information in your presentation
How does it look?
What can it do?
How does it move?
How does it sense its surrounding environment?
What are the standard missions it can perform?
Look back over your previous activities to help you answer these questions.
Remember, you are now pitching your idea to everyday people, not NASA scientists.
Chapter 20:
Building Instructions
These set of construction notes can be used to build the following assemblies
Left Wheel Assembly – Base Design
Right Wheel Assembly – Base Design
Attach LEFT and RIGHT wheel
assemblies to the NXT brick
Back Castor – Base Design
15
Turn the DomaBot around and attach the
back castor bracket to the back of the motors
Connect the motor cables to
‘B’ and ‘C’ ports as shown
Building Instructions - Pen Attachment
Attach marker pen firmly with rubber bands
7
7
Building Instructions
Touch Sensor Attachment (Port 1)
Connect Sensor cable to Port 1
2
2
2
5
5
5
9
Assemble the 2 sections together and
attach to the front of the DomaBot
Building Instructions 4
Light Sensor Attachment (Port 3)
Connect Sensor cable to Port 3
4
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