Lego Mindstorms NXT is a programmable

robotics Robotics is the interdisciplinary study and practice of the design, construction, operation, and use of robots. Within mechanical engineering, robotics is the design and construction of the physical structures of robots, while in computer s ...

kit released by

Lego Lego (, ; ; stylised as LEGO) is a line of plastic construction toys manufactured by the Lego Group, a privately held company based in Billund, Denmark. Lego consists of variously coloured interlocking plastic bricks made of acrylonitri ...

on August 2, 2006. It replaced the

Robotics Invention System Lego Mindstorms (sometimes stylized as ''LEGO MINDSTORMS'') is a discontinued line of educational kits for building programmable robots based on Lego bricks. It was introduced on 1 September 1998 and discontinued on 31 December 2022. Mindstor ...

, the first-generation

Lego Mindstorms Lego Mindstorms (sometimes stylized as ''LEGO MINDSTORMS'') is a discontinued line of educational kits for building programmable robots based on Lego bricks. It was introduced on 1 September 1998 and discontinued on 31 December 2022. Mindstor ...

kit. The base kit ships in two versions: the retail version and the education base set. It comes with the NXT-G programming software or the optional LabVIEW for Lego Mindstorms. A variety of unofficial languages exist, such as NXC, NBC, leJOS NXJ, and RobotC. A second-generation set, Lego Mindstorms NXT 2.0, was released on August 1, 2009, with a color sensor and other upgrades. The third-generation EV3 was released in September 2013.

NXT Intelligent Brick

The kit's main component is the NXT Intelligent Brick computer, which can accept input from up to four

sensor A sensor is often defined as a device that receives and responds to a signal or stimulus. The stimulus is the quantity, property, or condition that is sensed and converted into electrical signal. In the broadest definition, a sensor is a devi ...

s and control up to three

motors An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power gene ...

with a modified version of RJ12 cables (similar to, but incompatible with,

RJ11 A registered jack (RJ) is a standardized telecommunication network interface for connecting voice and data equipment to a computer service provided by a local exchange carrier or long distance carrier. Registered interfaces were first defined ...

phone lines). The plastic pin to hold the cable in the socket is moved slightly to the right. The brick has a 100×64 pixel monochrome

LCD A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers to display information. Liquid crystals do not em ...

and four buttons that can navigate a user interface with hierarchical menus. It has a 32-bit

ARM7TDMI ARM7 is a group of 32-bit RISC ARM processor cores licensed by ARM Holdings for microcontroller use. The ARM7 core family consists of ARM700, ARM710, ARM7DI, ARM710a, ARM720T, ARM740T, ARM710T, ARM7TDMI, ARM7TDMI-S, ARM7EJ-S. The ARM7TDMI and ...

-core Atmel

AT91SAM7 Atmel ARM-based processors are microcontrollers and microprocessors integrated circuits, by Microchip Technology (previously Atmel), that are based on various 32-bit ARM processor cores, with in-house designed peripherals and tool support. Overvi ...

S256 microcontroller with 256 KB of FLASH memory and 64 KB of RAM, an 8-bit Atmel AVR ATmega48 microcontroller, and Bluetooth support. The kit has a

speaker Speaker most commonly refers to: * Speaker, a person who produces speech * Loudspeaker, a device that produces sound ** Computer speakers Speaker, Speakers, or The Speaker may also refer to: Arts and entertainment * "Speaker" (song), by David ...

, and can play sound files at sampling rates up to 8 kHz. Power is supplied by 6

AA batteries The AA battery (or double-A battery) is a standard size single cell cylindrical dry battery. ANSI and IEC battery nomenclature gives several designations for cells in this size, depending on cell features and chemistry. The IEC 60086 system c ...

(1.5 V each) in the consumer version of the kit, and a rechargeable

Li-Ion A lithium-ion or Li-ion battery is a type of rechargeable battery that uses the reversible intercalation of Li+ ions into electronically conducting solids to store energy. Li-ion batteries are characterized by higher specific energy, energy d ...

battery in the educational version. The brick is compatible with sensors and motors of its successor

Lego Mindstorms EV3 LEGO Mindstorms EV3 (stylized: LEGO MINDSTORMS EV3) is the third and final generation of LEGO's Mindstorms robotics kit line. It is the successor to the second generation LEGO Mindstorms NXT kit. The "EV" designation refers to the "evolution" ...

Development kits

Lego has released

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...

firmware for the NXT Intelligent Brick and schematics for all hardware components. Several developer kits are available with documentation for the NXT: * Software Developer Kit (SDK), with information on host USB drivers, executable file format, and bytecode reference * Hardware Developer Kit (HDK), with documentation and schematics for the NXT brick and sensors * Bluetooth Developer Kit (BDK), documenting protocols used for Bluetooth communications

Programming

Simple programs can be created using the menu on the NXT Intelligent Brick. More complicated programs and sound files can be downloaded with a USB port or Bluetooth. Files can be copied wirelessly between two NXT bricks, and some mobile phones can be used as a remote control. Up to three NXT bricks can communicate simultaneously via Bluetooth when user-created programs are run. The kit's retail version includes software for writing programs that run on Windows and Mac OS personal computers. The software, based on

National Instruments The National Instruments Corporation, doing business as NI, is an America, American multinational corporation, multinational company with international operations. Headquartered in Austin, Texas, Austin, Texas, it is a producer of automated tes ...

LabVIEW, provides a visual programming language for writing simple programs and downloading them to the NXT Brick; instead of requiring users to write lines of code, they can use flowchart-like blocks to design their program. Ch is a C/C++ interpreter running C/C++ code to control Lego NXT or EV3. No firmware upload/download or compilation is needed. A C/C++ code running in Ch can control a Lego NXT, EV3, or multiple of NXT/EV3.

Sensors and actuators

The Lego Mindstorms NXT base kit includes: * Three

servo Servo may refer to: Mechanisms * Servomechanism, or servo, a device used to provide control of a desired operation through the use of feedback ** AI servo, an autofocus mode ** Electrohydraulic servo valve, an electrically operated valve that c ...

motors with built-in

reduction gear A gear train or gear set is a machine element of a mechanical system formed by mounting two or more gears on a frame such that the teeth of the gears engage. Gear teeth are designed to ensure the pitch circles of engaging gears roll on each oth ...

assemblies and internal optical

rotary encoder A rotary encoder, also called a shaft encoder, is an electro-mechanical device that converts the angle, angular position or motion of a shaft or axle to Analog signal, analog or Digital signal, digital output signals. There are two main types of ...

s which sense their rotations within one degree of accuracy. * A

touch sensor A touch switch is a type of switch that only has to be touched by an object to operate. It is used in many lamps and wall switches that have a metal exterior as well as on public computer terminals. A touchscreen includes an array of touch switche ...

detects whether it is pressed, has been bumped, or is released. The orange enter button and the gray right and left NXT buttons can be programmed as touch sensors. In the NXT-G programming software, a value of 0 is given when it is not pressed and a value of 1 is given if it is pressed. * A

light sensor Photodetectors, also called photosensors, are devices that detect light or other forms of electromagnetic radiation and convert it into an electrical signal. They are essential in a wide range of applications, from digital imaging and optical c ...

detects the light level in one direction, and includes an

LED A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresp ...

for illuminating an object. It can sense reflected light values with the built-in red LED, or ambient light. In the NXT-G programming software, it senses light on a scale of 0 to 100; 100 is very bright, and 0 is dark. If calibrated, the sensor can be used as a distance sensor. * A sound sensor measures volume on a scale of 0 to 100; 100 is very loud, and 0 is silent. * An

ultrasonic sensor Ultrasonic transducers and ultrasonic sensors are devices that generate or sense ultrasound energy. They can be divided into three broad categories: transmitters, receivers and transceivers. Transmitters convert electrical signals into ultrasou ...

can measure the distance from the sensor to something it is facing and detect movement. It can show distance in centimeters and inches. The maximum distance it can measure is , with a precision of . The sensor sends ultrasonic sound waves that bounce off an object ahead of it and then back, and senses the time it took. Other parts may be bought separately. Third-party companies manufacture sensors such as a

compass A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with No ...

gyroscope A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining Orientation (geometry), orientation and angular velocity. It is a spinning wheel or disc in ...

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

tracker,

RFID Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, a radio receiver, and a transmitter. When tri ...

reader and

accelerometer An accelerometer is a device that measures the proper acceleration of an object. Proper acceleration is the acceleration (the rate of change (mathematics), rate of change of velocity) of the object relative to an observer who is in free fall (tha ...

sensors sold by Lego. The temperature sensor can measure in Celsius or Fahrenheit.

Connector

Sensors are connected to the NXT brick with a six-position

modular connector A modular connector is a type of electrical connector for cords and cables of electronic devices and appliances, such as in computer networking, telecommunication equipment, and audio headsets. Modular connectors were originally developed fo ...

with analog and digital interfaces. The analog interface is backward-compatible (using an adapter) with the older Robotics Invention System. The digital interface is capable of I²C and

RS-485 RS-485, also known as TIA-485(-A) or EIA-485, is a standard, originally introduced in 1983, defining the electrical characteristics of drivers and receivers for use in serial communications systems. Electrical signaling is balanced, and Telecomm ...

communication.

NXT 2.0

Lego Mindstorms NXT 2.0 is the second set in the

series, introduced on August 5, 2009, at the Lego Shop in the U.S. The set contains 619 pieces, including a sensor that can detect colors. It was followed by the

Features

* A sound editor for recording a sound and programming the NXT brick to play it. * An image editor for downloading an image to the NXT brick to appear on the screen.

NXT intelligent brick

* 32-bit Atmel

S256 main

microcontroller A microcontroller (MC, uC, or μC) or microcontroller unit (MCU) is a small computer on a single integrated circuit. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable input/output peripherals. Pro ...

(256 KB

flash memory Flash memory is an Integrated circuit, electronic Non-volatile memory, non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for t ...

, 64 KB

RAM Ram, ram, or RAM most commonly refers to: * A male sheep * Random-access memory, computer memory * Ram Trucks, US, since 2009 ** List of vehicles named Dodge Ram, trucks and vans ** Ram Pickup, produced by Ram Trucks Ram, ram, or RAM may also ref ...

) * 8-bit Atmel ATmega48 microcontroller @ 4 MHz (4 KB flash memory, 512 Bytes RAM) * 100×64 pixel

screen * Four RJ12 input ports (ports 1–4) * Three RJ12 output ports (ports A-C) * USB port * Bluetooth Class II V2.0 * Loudspeaker – 8 kHz sound quality, 8-bit resolution, 2–16 kHz sample rate * Four push buttons to navigate menus and use in programs * Powered by six AA batteries or the NXT rechargeable battery

References

External links

lego.Edutech.com
Official Lego Education partner
external controller with open hardware beaglebone

Program NXT, help for programming your Lego Mindstorms NXT

HiTechnic.com
LEGO Certified Sensors for the Lego Mindstorms
mindsensors.com
Sensors for the Lego Mindstorms NXT
Trinfactor3.com
Enables use of 32 analog sensors with 1 NXT
robojoy-club
NXT robot and program for beginner
Placing and Fitting Gears

Roberta
Educational Robotics
Lego Mindstorms Community and Projects

Read This Review Before You Buy Lego Mindstorms EV3

Lego Mindstorms NXT and Lego Mindstorms NXT 2.0 Projects

The NXT 2.0 Shooterbot in action
{{Robot kits Lua (programming language)-scriptable hardware Robot kits Products introduced in 2006 2006 in robotics