LEGO MindStorms NXT User manual

NXT User Guide

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WELCOME TO LEGO®MINDSTORMS®EDUCATION
LEGO®MINDSTORMS®Education is the next generation in
educational robotics, enabling students to discover Science,
Technology, Engineering and Mathematics in a fun, engaging,
hands-on way.
By combining the power of the LEGO building system with
the LEGO MINDSTORMS Education technology, teams of
students can design, build, program, and test robots. Working
together on guided and open-ended engineering projects,
the team members develop creativity and problem-solving
skills along with other important mathematics and science
knowledge. Students also become more skilled in
communication, organization and research, which helps
prepare them for future success in higher levels of schooling and in the
workplace.
The next technology now.
LEGO MINDSTORMS Education features an advanced 32-bit computer-
controlled NXT brick, Interactive Servo Motors, Sound, Ultrasonic and other
sensors, Bluetooth communication and multiple downloading capabilities. The
icon-based LEGO MINDSTORMS Education NXT Software is built on the
LabVIEW™ software from National Instruments, an industry standard with
applications in many engineering and research fields.
Curriculum. Inspiration. Support.
The LEGO MINDSTORMS Education website www.MINDSTORMSeducation.com
is your main resource for curriculum, training, product information and support.
Our partners provide a strong network of information, technical advice, and
teacher support as well. Carnegie Mellon Robotics Academy is our partner for
developing curriculum materials and activities. Tufts University Center for
Engineering Education Outreach (CEEO) is our partner for product
development, workshops and conferences. In addition, local support is
provided by our trade partners. If you are interested in a competitive challenge,
check our website to find out more about the FIRST LEGO LEAGUE.
Start here.
This User Guide provides an overview of the components and features in the
LEGO MINDSTORMS Education NXT materials.
Enjoy!
Introduction

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Introduction
Build. Program. Test. ................................... 4
Technology
Overview ......................................................... 5
Installing Batteries In The NXT................ 7
Connecting The NXT Technology ........... 9
About The NXT Brick................................... 11
NXT Main Menu ............................................. 14
Touch Sensor................................................. 23
Sound Sensor................................................ 25
Light Sensor................................................... 27
Ultrasonic Sensor......................................... 29
Interactive Servo Motor ............................. 31
Lamps .............................................................. 33
Using Bluetooth............................................. 34
Software
Installing The Software ..............................
44
Your First Program....................................... 46
Software User Interface............................. 48
The Robot Educator .................................... 50
Programming Palette.................................. 53
The Configuration Panel ............................ 57
The Controller................................................ 57
Parts List For Base Set #9797...................... 58
Useful Information
Download To Multiple NXTs ...................... 61
Troubleshooting ............................................ 63
Table of Contents
Introduction

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Build. Program. Test.
Build
Build your robot. Specific building
instructions for a robot are provided
with this User Guide. There are also
building instructions for the same robot
in the NXT Building Guide found in
the Base Set #9797 and in the Robot
Educator, which is part of the LEGO®
MINDSTORMS®Education NXT Software.
Program
Program your robot using the LEGO
MINDSTORMS Education NXT Software.
Many examples are included in the
Robot Educator part of the software.
Download your program to the NXT brick
with the wireless Bluetooth connection
or the USB cable.
Test
Run your program. What happens? Did
your robot perform as you expect? If not,
adjust your robot or your program and
try again!
Start Here
If you prefer to start by building and programming using the
NXT brick display without a computer, go to the NXT Building
Guide.
Introduction

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Attaching the sensors
Sensors can be plugged into any input port
numbered 1-4. Any wires except the converter wire
can be used to connect the sensors.
The default settings used for the test programs
on the NXT and for many sample programs in the
Robot Educator are as follows:
Port 1: Touch Sensor
Port 2: Sound Sensor
Port 3: Light Sensor
Port 4: Ultrasonic Sensor
Technology
NXT Brick
An intelligent, computer-controlled LEGO® brick, the NXT is
the brain of the LEGO MINDSTORMS®Education robot.
Touch Sensors
Enable the robot to respond to
obstacles in the environment.
Overview
Light Sensor
Enables the robot to respond to
variations in light level and color.
Sound Sensor
Enables the robot to respond to
sound levels.
Ultrasonic Sensor
Enables the robot to measure
distance to an object and to
respond to movement.

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Rechargeable battery
Provides power to the NXT so the robot can move
and respond.
Attaching the Motors and Lamps
Motors or Lamps can be plugged into any output
port A, B, or C.
The default settings used for the test programs
on the NXT and for many sample programs in the
Robot Educator are as follows:
Port A: Motor or a Lamp for an extra function
Port B: Motor for movement; for a two-Motor
chassis, often this is the left side.
Port C: Motor for movement; for a two-Motor robot,
often this is the right side.
Overview
Interactive Servo Motors
Ensure that robots move smoothly and precisely.
Technology
Lamps &
Converter Cables
Add lamps and then program flashing
lights, or use them to activate the light
sensor, or just for fun! Three Lamps
and three Converter cables are
included in the Base Set.

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1 2 Rechargeable battery
The rechargeable battery fits into the bottom of the
NXT. To install the rechargeable battery, move the
plastic tab on the side with your thumb to open the
back.
The NXT comes with an extra cover that is used when
6 AA batteries are used. (See details on the next
page.)
Holding the rechargeable battery, press in the plastic
tab and snap the battery into place.
Installing Batteries In The NXT
To recharge the battery, attach one end of the power adapter
cord (sold separately) into the charge plug just below the NXT
input ports. Attach the other end of the power adapter cord
into the wall socket. The battery may also be charged when
not inserted into the NXT.
• The green indicator light turns on when the power adapter
is connected to the NXT.
• The red light turns on when the battery is recharging. The
red light turns off when the battery is fully recharged.
• Fully recharging the battery requires approximately four
hours.
• The NXT can be used when the battery is recharging;
however, recharging then requires more time.
• This Li-Ion Polymer battery can be recharged up to 500
times.
When you first use the rechargeable battery in the NXT itself,
attach the transformer and let the battery and NXT charge
together for approximately 20 minutes before starting. You
may also need to do this if the rechargeable battery was
completely depleted before recharging.
Note: You will need to charge the battery first before
using it.
Technology

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Other battery types
The NXT also operates using six AA/LR6 batteries.
• Alkaline batteries are recommended.
• Rechargeable AA/LR6-type batteries can be used;
however, the power performance of the NXT may be
reduced.
Batteries low
When the battery power is low, this icon flashes on and
off in the NXT display.
Installing Batteries In The NXT
The NXT will Sleep to conserve power. To change the time or
set Sleep to Never, go to Settings/Sleep/Never. You can also
change the Settings to wait before going to Sleep from 2, 5,
10, 30, or 60 minutes.
Technology
Important!
• Never mix different types of batteries in the NXT.
• Always remove batteries prior to long-term
storage.
• Promptly remove depleted batteries from the NXT.
• Only recharge batteries under adult supervision.
• Never attempt to recharge non-rechargeable
batteries.

CB A
1234
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Connecting Motors
To connect a Motor to the NXT, plug one end of a black wire
to the Motor. Plug the other end into one of the output ports
(A, B, C).
Connecting sensors
To connect a Sensor to the NXT, plug one end of a black wire
into the Sensor. Plug the other end into one of the input ports
(1, 2, 3, 4).
Downloading and uploading
The USB port and wireless Bluetooth connection are used for downloading
and uploading data between your computer and the NXT.
If your computer has Bluetooth, you can download programs to the NXT
without using the USB cable.
If your computer does not have Bluetooth, you must use the USB cable or
buy a Bluetooth dongle for your computer. (Read more about the wireless
Bluetooth connection on pages 34-43).
Connecting the NXT Technology
Technology
Note that ALL of the black
6-wire cables can be used in
both input and output ports,
sensors and motors. Work
sensors MUST be attached
to the input ports (1-4) and
motors MUST be attached to
the output ports (A-C).

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2
3
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Turn on the NXT.
Connect the PC and the NXT with the USB cable.
Connecting the NXT to a Macintosh with a USB cable
Make sure the LEGO MINDSTORMS Education NXT Software is installed before connecting your
NXT to your Macintosh. (See the installation instructions on page 45.)
Turn on your NXT.
Connect the USB cable to the NXT.
Connect the USB cable to the Macintosh and you’re ready to go.
Make sure the LEGO
MINDSTORMS Education NXT
Software is installed on your
computer before connecting
the NXT to the computer.
See page 44 for installation
instructions.
Connecting the NXT Technology
When the PC identifies the NXT it will automatically finalize
the installation of the LEGO®MINDSTORMS®Education NXT
Software.
Technology

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NXT Interface
The NXT brick is the brain of the LEGO®MINDSTORMS®
Education robot. It is a computer-controlled LEGO brick that
provides programmable, intelligent, decision-making behavior.
Power Plug
If you are using the rechargeable battery and need to
recharge it, or if you are not using 6AA batteries, you can
connect a power adapter to the NXT using the power plug.
(Power adapters are sold separately.)
USB port
Connect a USB cable to the USB port and
download programs from your computer
to the NXT (or upload data from the robot
to your computer). You can also use the
wireless Bluetooth connection for uploading
and downloading.
USB icon
When you connect your NXT to a
computer with a USB cable, a USB icon
will be displayed. If you disconnect the
USB cable, the icon will disappear.
Bluetooth icon
The Bluetooth icon shows the current
status of any wireless Bluetooth
connections. If there is no Bluetooth icon
shown, Bluetooth is Off.
Bluetooth is On but your NXT is not
visible to other Bluetooth devices.
Bluetooth and On and your NXT is visible
to other Bluetooth devices.
Bluetooth is On and your NXT is
connected to a Bluetooth device.
USB connected and working fine.
USB connected but not working properly.
Output ports
The NXT has three output ports labeled
A, B, and C for Motors or Lamps.
About The NXT Brick
Technology

About The NXT Brick
Loudspeaker
When sounds are included in a
program, you can hear them through the
Loudspeaker.
Battery level
The battery icon displays the NXT power
level. When the battery power is low
(below about 10% capacity), the battery
icon flashes on and off.
Running icon
When the NXT is turned on, the running
icon spins. If the running icon stops
spinning, the NXT has frozen and
you must reset it. (See page 63 for
Troubleshooting steps).
Turning off your NXT
1. Press the Dark Gray button until you
see this screen.
2. Press the Orange button to turn off the
NXT. Press the Dark Gray button to go
back to the NXT main menu.
NXT buttons
Orange: On/Enter.
Light gray arrows: Navigation, left and right
Dark Gray: Clear/Go back.
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Technology
Input ports
The NXT has four input ports for attaching
sensors. The sensors must be attached to
port 1, 2, 3, or 4.

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Technical specifications
• 32-bit ARM7 microprocessor
• 256 Kbytes FLASH, 64 Kbytes RAM
• 8-bit microprocessor
• 4 Kbytes FLASH, 512 Byte RAM
• Bluetooth wireless communication,
Bluetooth class II V2.0 compliant
• USB 2.0 port
• Four input ports, six-wire digital platform
• Three output ports, six-wire digital platform
• Dot matrix display, 60 x 100 pixels
• Loudspeaker, 8 KHz sound quality
• Power source: Rechargeable lithium battery
or six AA Batteries
• Plug for power adapter: US: 120VAC 60Hz
UK, EU, AUS: 230~ 50Hz
Naming the NXT
You can change the name of your NXT by going to the NXT
window in the software. This window is accessible from the
Controller. NXT names can be at most eight characters long.
NXT display options
Your NXT has many other features.
Read more about them on the following
pages.
About The NXT Brick
Technology

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In the My Files [My Files] submenu you can store all the
programs that you have made on the NXT or downloaded
from your computer.
Files are automatically placed into the appropriate folders. When you download a
program using a Sound file to the NXT, the program will be placed under Software
files while the sound data will be placed under Sound files.
When you Select a file, you can send it to other NXT units. Read more about this
in the section Connecting Your NXT to Another NXT on page 42.
My Files
NXT Main Menu
Technology
There are three different subfolders:
Software files [Software files] –
programs you have downloaded from
your computer.
NXT files [NXT files] – programs you
have made on the NXT.
Sound files [Sound files] – sounds
that are part of a program that you
download.

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NXT Program
NXT Main Menu
Technology
Select Forward [Forward]. Use the Light
Gray Arrow buttons to move through
the choices and then press the Orange
button Enter [Enter] to make your
selection.
Select Touch [Touch]. Select Backward [Backward].
You don’t need a computer to program a robot. Using the
NXT Program [NXT Program] submenu, you can make many
programs without your computer.
Try this program to see how easy it is.
Make the robot go back and forth when the Touch Sensor
is pressed. First, the robot will move forward until the Touch
Sensor is pressed, and then it will move backwards. When its
Touch Sensor is pressed again, the robot will move forward
once again. This will continue indefinitely until you stop the
program.
Make sure the sensor and motors are connected to the right
ports. The Touch Sensor is connected to port 1. The Motors
are connected to ports B and C.

1.
2.
3.
4.
4 5 6
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NXT Main Menu
Technology
Select Touch [Touch] again. Now select Loop [Loop] to make the
program run again and again until you
turn off the NXT.
Now you can run the program. Simply
select Run [Run].
Try these programs as well.

1 2 3
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The Try Me [Try Me] feature allows you to experiment with the
Sensors and Motors using programs that are ready to run.
To start, press the Light Gray Arrow on the left to go to Try Me.
Then press the Orange button to select Try Me.
Try Me
NXT Main Menu
Select some other Try Me programs to experiment with other
Sensors and the Motors.
Try Me files can be deleted in the Settings [Settings]
submenu (see page 19). However, to get them back onto the
NXT, you would need to download the firmware again (see
page 63).
Technology
Press the Light Gray Arrow to the right to
go to Try-Touch program.
Press the Orange button to select it.
Press the Orange button again to Run
the Try-Touch program.
Make sure the Touch Sensor is in port 1.
Press the Touch Sensor button.
The program Loops continuously so
press the Dark Gray button to stop the
program.
Important
Use the default port settings
for the Motors, Lamps and
Sensors as explained on
pages 5-6. See pages 23-33
for specific examples using
each of the Sensors and the
Motor.

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View
Connect Sensors or Motors to the NXT port(s). View
[View] will help you select the right port or check the
default settings.
Select View [View] in the NXT display.
In the View [View] submenu, you can do a quick test of
your Sensors and Motors and see the current data for
each.
NXT Main Menu
Technology
Select the icon of the Sensor or Motor
that you want to test. You can only get
readings from one sensor or motor at a
time.
Select the port to which the Sensor or
Motor is attached.
The data from the Sensor or Motor
appears on the display.

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Settings
In the Settings [Settings] submenu, you can adjust the
different settings of the NXT, such as Loudspeaker volume or
Sleep [Sleep] mode. In this submenu, you can also delete the
programs that you have stored in the NXT memory.
NXT Main Menu
Technology
Sleep [Sleep] mode:
You can set your NXT to be turned off
after 2, 5, 10, 30 or 60 minutes when it is
not being used. You can also select the
Never [Never] setting so that the NXT
remains on until you turn it off. Please be
aware that this drains the batteries more
quickly.
Change Volume:
Here you can adjust the volume of the
NXT speakers in a range of 0 (Off) to 4
(Loud).
Delete all programs:
You are able to delete the programs
from four subfolders: Software files, NXT
files, Sound files, and Try Me files.

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Bluetooth - NXT main menu
In the Bluetooth [Bluetooth] submenu, you can set a
wireless connection between your NXT and other Bluetooth
devices, such as other NXT units, mobile phones, and
computers.
You can use a wireless connection to download programs
without using a USB cable. You can even program a mobile
telephone to control the NXT!
Read more about wireless Bluetooth communications on
pages 34-43.
NXT Main Menu
Technology