NXT Basics: Technic Building and NXT-G

Erin Cejka RieckerCenter for Engineering Educational OutreachTufts University

Getting to Know the NXT

Motors and Sensors

Hardware Comparison

Technic or “Studless” Building

Pieces: Studless beams Connectors Axles

Features: Symmetry Sturdy

Build a Two Motor Car

Software Options

ROBOLAB 2.9

LEGO Mindstorms for NXT(NXT-G)

Using ROBOLAB 2.9 with the NXT New sensors

Screen control

Using ROBOLAB 2.9 with the NXT

NXT control panel appears during download

NXT-G Interface

Toolbar

Workspace

Configuration Panel

Help & Navigation

ControllerPalettes

Tutorials

Web Portal

Sequence Beam

NXT-G tools

Pointer tool: move blocks, select blocks Pan tool: move within workspace Comment tool: add notes to your code

Intro to NXT-G: Palettes

Common: Complete:Custom:

Most All blocks Downloadedcommonly and createdused blocks blocks

Writing a Basic Program Drag and drop block(s) on sequence

beam

Manipulate Configuration Panel & Download

Intro to NXT-G: Controller

Download & Run Selection

Download & Run

NXT Window

Download Stop

ROBOLAB vs. NXT-G

ROBOLAB vs. NXT-G

In ROBOLAB In NXT-G

Icons or VIs Blocks

Modifiers Configuration Panel

Wiring together icons Sequence beams

Need start & stop light

Start is given, no stop needed

NXT Rotation Sensor

Built in to motors Measure degrees

or rotations Reads + and - Degrees:

accuracy +/- 1 1 rotation =

360 degrees

Viewing Sensors

Connect sensor Turn on NXT Choose “View” Select sensor type Select port

NXT Sound Sensor Sound sensor can measure in dB and dBA

dB: in detecting standard [unadjusted] decibels, all sounds are measured with equal sensitivity. Thus, these sounds may include some that are too high or too low for the human ear to hear.

dBA: in detecting adjusted decibels, the sensitivity of the sensor is adapted to the sensitivity of the human ear. In other words, these are the sounds that your ears are able to hear.

Sound Sensor readings on the NXT are displayed in percent [%]. The lower the percent the quieter the sound.

http://mindstorms.lego.com/Overview/Sound_Sensor.aspx

Challenge: Stop with sound

Program your NXT car to drive until you yell “Stop”

Example Program: Stop with Sound

NXT Ultrasonic/Distance Sensor Measures

distance/proximity

Range: 0-255 cm Precision: +/- 3cm Can report in

centimeters or inches

http://mindstorms.lego.com/Overview/Ultrasonic_Sensor.aspx

Challenge: Parking NXT

Program your NXT car to drive forward until you “find a parking spot” (hit a touch sensor)

The car should then turn into the spot, and stop when it gets close enough to wall.

Example Program: Parking NXT

A note about NXT memory Memory space is limited! To clear space, use NXT window Show and delete system files for more

space

NXT Structure: Loops

Challenge: Stay on Table

Program your NXT to stay on the table

Example Program: Stay on Table

NXT Structure: Switch

Challenge: Remote Control

Program car to drive while the touch sensor is pushed and stop while the touch sensor is released

Example Program: Remote Control

NXT Sound NXT can play sound files or notes Sounds take up more memory space

NXT Display Display images, text, or drawings Choose location on display screen 100 x 64 pixels (up to 7 lines of text) Graphics take up memory space

Challenge: Say Hello

Have the RCX say hello using sound and the display screen

Don’t forget – the program ends after the last block. You may need a wait for to see the display.

Caution: one of the options in the configuration panel is Clear – use it to clear screen. Otherwise, uncheck the box!

Example Program: Say Hello

My Blocks

Create custom blocks Saved in custom palette Download blocks from the web

Creating My Blocks

Write the code for the My Block

Creating My Blocks

Select all the blocks to be used for My Block

Creating My Blocks Choose “Create My Block” on toolbar Or, go to the Edit menu and select

“Make a new My Block”

Creating My Blocks Name My

Block

Add a description

Creating My Blocks Create a

custom icon

Creating My Blocks

My Block appears in Custom Palette

Challenge: Create My Block

Come up with a program where you might use a My Block

May use it to repeat actions or to conserve workspace

Example Program: Create My Block This program displays “If you’re happy

and you know it, press the touch sensor (and hold it)!”

If the touch sensor if pressed, it displays a happy face, otherwise it displays a sad face

A My Block is used for the text display

Example Program: Create My Block

Design Challenge: Alarm System Build an alarm system using the NXT Alarm can be triggered by any sensor

(or use more than one) Alarm should have an audio component Alarm can use display or motors as well