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Building Mindstorms NXT Robots. Dr. David Johnson School of Computing. What Is a Robot?. Resources for Learning About Robots. Web Wikipedia http://en.wikipedia.org/wiki/Robot New Scientist http://www.newscientist.com/article/dn9973-instant-expert-robots.html Youtube Many! MAKE magazine
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Building Mindstorms NXT Robots Dr. David Johnson School of Computing
Resources for Learning About Robots • Web • Wikipedia • http://en.wikipedia.org/wiki/Robot • New Scientist • http://www.newscientist.com/article/dn9973-instant-expert-robots.html • Youtube • Many! • MAKE magazine • Boy Scout badge guide is quite nice and cheap • Consider exercising your team’s FLL skills by having them look at some of these resources
Some Example Robots • Big Dog • http://www.youtube.com/watch?v=b2bExqhhWRI • Planetary Exploration • http://www.youtube.com/watch?v=nb2GsD7TAjU&feature=related • Home assistance • http://www.youtube.com/watch?v=GTxW3GWZ5hI • Hobby • http://www.youtube.com/watch?v=zX09WnGU6ZY
What Is a Robot? • Sense • Update information about the world • Plan • Modify original plan in response to this sensed information • Act • Move in the world or make a change in the world
Mindstorms NXT • Can it? • Sense • Plan • Act
Mindstorms NXT • It can • Sense • Light intensity and color • Sound intensity • Button presses • Distance to nearby objects • Wheel revolutions • Plan • Act
Mindstorms NXT • It can • Sense • Plan • Small computer brain • “the brick” • Graphical programming language • Act
Mindstorms NXT • It can • Sense • Plan • Act • Three motors that turn
Goals For Today • Raise your comfort level with Mindstorms • Building • Programming • There is no substitute for doing it • Try some common tasks • Wheeled robot • Respond to sensors • Maybe a taste of competition…
Testing Equipment • Plug in motors, sensors • A critical thing to know is the view program • Let you read values from sensors without writing a custom program
Building • Not “normal” LEGO pieces • Based on the Lego Technic build system • Pegs and holes • Can be frustrating • Stable • One peg makes a rotary joint • Multiple pegs lock two pieces in place • Strong • Keep in close to the main body • The wheel axes must not be wobbly and flex!
Building Resources • There are lots of instructions for building things online • http://www.nxtprograms.com/ • Have the team try some out • Learn things that work • Then modify • Don’t get too distracted with NXT guitars, guns, etc. • 5 minute bot • A quick base • Probably not good to adapt for competition
Programming • Programming teaches • Breaking complex problems into solvable parts • Precise thinking and specification • Creative experimentation to discover and isolate problems • Programs are designed on a base computer • Downloaded by USB cable to the brick
Programming the Brick • LEGO Mindstorms NXT • Default language for programming Mindstorms • Designed to be friendly • Nice tutorials • Try them with your team • Not based on traditional programming languages • Easy to do very basic things • More difficult to advance • It does have some subtle actions that can cause confusion
Learning to Use the Tutorial • Each tutorial is structured as • Challenge • Build • Program • The mobile base from the tutorials is not my favorite • Takes too long to build • Difficult to modify
A Quick Programming Tour • Control goes along the path • Each block performs some action • Most blocks are very flexible • Learn the options at the bottom panel • Many actions continue until • A sensor is triggered • Time has passed • A commanded result is finished
A Quick Test • Attach a motor to the brick (ports A,B,C) • Attach a touch sensor to the brick (ports 1,2,3,4) • Write a program • Move block • Set duration to unlimited • Wait until touch • Move block • Set the brakes • Download to brick • Run it
Additional Resources • There is a lot to learn, but you can get started pretty quickly • I recommend • Winning Design! LEGO Mindstorms NXT: Design Patterns for Fun and Competition • Most FLL-centric of the books • Beginning to medium skill level • If you don’t have prior experience, I think you would be foolish not to look at this book. • Parts of my FLL camp notes • More for getting a novice team started
Let’s have a competition! • Go through maze • Stop before unknown finish “wall” • How to solve? • Detect or dead reckoning • Development cycle • Build, test, adjust, repeat • Most kids do not understand how to test and modify something until it works