Physics 235 Robotics Workshop January 2007 Course Instructor: Tom Huber

2 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

3 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

4 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!

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

6 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)

7 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

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

9 Ultrasound Sensor  Similar to echolocation used by batsecholocation  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

10 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 to detect on left and right Infrared Sensors

11 Light Sensors (Edge of Ring)