Lego Mindstorms NXT

Lego Mindstorms NXT is a robotic kit. It is made to build and program first robot in 30 minutes. The kit replaces a system called Robotics Invention System. The available versions are: Lego Mindstorms NXT 1.0 (set #8527), Lego Mindstorm NXT 2.0 (set #8547) and Lego Mindstorms Education NXT (set #9797). It comes with the NXT-G programming software. It is possible to use unofficial programming languages, such as NXC, NBC, leJOS NXJ, and RobotC using software that is not included with the kit.

"Golf bot" — a robot built with the NXT set

The main component in the kit is computer module that controls the robot's movements and actions called the NXT Intelligent Brick. It has 32-bit microprocessor, four inputs, three outputs, Bluetooth communications, a speaker, 1 USB 2.0 port, and a 100×64 LCD display. Also, the NXT includes three powerful servo motors with rotation sensors. Very simple programs can be created in the menu on the NXT Intelligent Brick without a computer. More complicated programs can be downloaded via Bluetooth or USB from the computer to the robot. The graphical, drag-and-drop programming language NXT-G is simple, but complete enough to be usable.

The NXT comes with five types of sensors: Touch, Light, Sound, Ultrasonic, and Rotation. The sound sensor is not included in the Lego Mindstorms NXT 2.0 kit.

• The touch sensor reacts to touch and release. It can detect single or multiple button presses, and reports back to the NXT Intelligent Brick.
• The Light Sensor enables the robot to decide what is light and what is dark and the light intensity, or hue, of different colors.
• The Sound Sensor is able to measure noise levels in both dB (decibels) and dBA (frequencies around 3–6 kHz where the human ear is most sensitive)
• The Ultrasonic Sensor is able to detect an object and measure distance in inches or centimeters.
• The Rotation Sensor is built into every motor so position and speed are always available to NXT programs.

In the Lego Mindstorms NXT 2.0 is new Colour sensor. It can detects different colours and measure the amount of reflected light and ambient light.