LEGO Mindstorms NXT 2.0


Lego Mindstorms were chosen as a culminating project for our unit to develop critical thinking, problem solving, and procedural thinking skills. There are excellent project resources available online with clear step by step visual directions. Programming the robots using the Lego Lab View interface was challenging. Program nuggets could be modified or added to student's program sequences. Quickly students learned to record their own voices and upload to the control module of the bot so it could speak in their voices. Programming precise motion or movements proved considerably more challenging for all students.

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Students started out building bots using projects from NXT 2.0 Projects website. These projects are rated by building and programming difficulty so it was an excellent resource for our classroom. The students found very well done project instructions and were able to use program modules and expand on them to perform more motions and functions. Students built the "Five Minute Bot" (which took almost an hour to build), the Castor Bot, Bumper Car, Explorer Bot, and Line Follower Bot.

The Line Follower Bot integrated a sensor in the bot that provided feedback about where the bot is related to the edge of a contrast in color. Students devised a series of tests to figure out HOW the sensor worked. They used black electrical tape on the floor of the classroom to create their own path, learned that a high degree of contrast was required, learned that sharp corners confuse the bot, and that it will turn around and find the line again once it reaches the end.
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Students constructed several different types of paths,
ranging in width from fat string all the way to 2" wide. They
found that black on silver works well as shown above, a
light stripe between two black tape lines also works well.

The Line Follower bot (Building Link) provided a great discussion focus on experimental design. At the end of the first class and first trial run, students had many questions about how the sensor worked. After generating a list of possible ways the bot knew where to go, students created a list of testing they could conduct to better understand the bot. Each group took on a different set of materials, dimensions, path smoothness, and other identified scenarios to test. After making multiple observations across the various scenarios, the limitations and ideal lines were uncovered. It was a very rich experience for all students, ALL engaged in the high level conversation.


The Lego robotics project proved frustrating for some students and highly engaging and fun for others. There were very few students who fell somewhere in between. Project plans from the NXT 2.0 Projects website were well received by nearly all students, each project clearly presented with a degree of detail necessary. Projects from Lego directly, presented within the NXT software interface (many projects included in software) lacked accuracy, detail, and clear procedures for building.


Feedback from the students comparing NXT 2.0 Projects to the Lego projects showed clear understanding about the need for specific detail and clear step by step directions. The language used revealed significant growth in their understanding of procedures and valuing of clear quality procedures. Being able to enthusiastically discuss, compare, contrast, and articulate their thoughts left no doubt about their growth even when their growth in writing procedures may not have shown a large amount growth.



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Explorer Bot Movie

https://vimeo.com/68132137
external image IMG_3467.JPG

E:Explorer Bot Movie from cnburch on Vimeo.