Lego Mindstorms NXTThe Lego
MINDSTORMS NXT Robotics kit uses motors, sensors, Lego Mindstorms
building parts and a small computer called the "NXT Brick" to create
Robots that one can program using the MINDSTORMS NXT software.
Like Scratch, MINDSTORMS NXT uses icons or
blocks that represent programming commands. Definition of a Robot: A Robot is a
machine that can be programmed to do a task without being directly
controlled by a human being. There are two parts to a
robotic system. 1. Hardware: This is the mechanical robot. The motors, gears, wheels, parts, computers that make up the machine. This is the part you build. 2. Software: This is the
instructions for the tasks and actions the robot will do. This is
the part you write. MINDSTORMS
NXT is used to create the software that controls the actions of the
robot hardware. NXT MINDSTORMS software is a visual/icon system
of assembling instructions. The flow of direction usually moves
from left to right. This software is an example of a compiled
program. Programs you write in NXT must be compiled and
downloaded to the NXT Brick before the Robot will perform the
program. (Scratch and Python are "Interpreted Languages.") Example 1: Overview of MINDSTORMS NXT User
Interface
Example 2: Movement Blocks Movement
Blocks direct motors A, B, or C to rotate clockwise or
counterclockwise. The motors have sensors inside them that can
measure how much they rotate. Motors C and B usually are used for
the drive wheels on a vehicle Robot. You may change the
following variables on a motor on the details window. Example 3: Loop Blocks Loop Blocks are like the "Repeat" or "Forever" functions in Scratch. You may define how many times an action or set of actions is to repeat. You may also use this like a conditional statement and have the loop work when a sensor or variable presents a certain value.  Loop Icon Example 4: Switch Block This is another use of the for conditional statements. (Like the "If" Block in Scratch) The Switch Block can use sensors or values to switch between differenct actions.  Example 5: Light Sensor The Light Sensor senses differences in light intensity (brightness). This value can be used to sense the light around the robot or differences in reflected light off of surfaces like the floor. Example 6: Motion/Ultrasonic Sensor The Motion/Ultrasonic Sensor uses high frequency sound waves and echos to detect the distance between the sensor and other objects. Example 7: Touch Senson This button can sense in three modes, pressed, released, and pressed and released. This enables the robot to sense when it is touching or bumping another object. Example Programs for basic vehicle robots: 1. Move Forward and Back  2. Move Forward, Spin, and Back  3. Using Sensing and Touch to allow the robot to move about the room and not bump into walls or other objects.  4. Click Here for Advanced Programming Ideas Sending (Uploading) the program to the NXT Brick. In the lower right hand corner of the NXT user interface allows for communication between the computer and the NXT Brick that controls the robot.
 Sample Robot Projects |
