Physics 235

Robotics Workshop

January 2007

Course Instructor: Tom Huber

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Rules of Lego Sumo Mass of less than 900 grams (about 2 pounds) for the bot At start of the round, must be less than 7.5” across, but can be as tall as desired No projectiles or weapons meant to disable other bots

36” Diameter Sumo Ring

Bot will remain motionless for five seconds at start

Each round lasts 90 seconds or till a bot touches outside +1 point for winning bot, -1 for loser, 0 for tie Restart if bots are hopelessly pushing in circles

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About The Class Class met five days per week, two hours per day with additional open lab time

First week – building and programming Parallax BOE Bots

Remainder of class, build Sumo Bots Build their structure from Lego bricks Write programs for the ZX24A processor Construct sensors

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Special Thanks Max Hailperin and Mike Hvidsten

Previous instructors of this course

Office of Dean of Faculty Funding for purchasing the new robotics kits

Don Kinzer, President of Elba Corporation Donating ZBasic ZX24A processors

Scott Hagemeyer (Gustavus Class of 2007) Teaching assistant for this course

All of you for attending!

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Anatomy of a Lego Bot Processor board with ZBasic ZX24A Processor Ultrasound Sensors (Distance) Infrared Sensors (Distance) Light Sensors (Edge of ring)

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Comparison with Lego Mindstorms Mindstorms

Three inputs and three outputs Premade sensors (touch, light, rotation, etc.) Graphical programming language

ZBasic ZX24A Processor Sixteen ports – can be inputs or outputs Build your own sensors and wire interface Text-based programming language (Visual Basic)

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ZBasic ZX24a Processor Donated by Elba Corporation ($60 for each processor)

In exchange, students wrote application notes

Much more capable than BOE Bot BS/2 processor 100x more memory 30x faster Analog input ports to directly measure light sensors

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Sample ZBasic Code Based on Visual Basic programming language Student programs are hundreds of lines long

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Ultrasound Sensor Similar to echolocation used by bats Emits a pulse of sound (40kHz, beyond human hearing) Sound travels at 343 m/s and reflects off object Time delay between pulse and echo gives distance

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Infrared Sensors Used to detect other bots Emits infrared (not visible) pulses of light (38 kHz) Light reflects from object The brightness of reflection

gives approximate distance

Often used in pairs todetect on left and right

Infrared Sensors

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Light Sensors (Edge of Ring)