1. Kedar Hiremath Andrew Floren Josh Armstrong Matt deWet

2. Overview of Presentation Introduce the Configurable Laser Tag System Design and Implementation Problems Encountered Cost and Other Considerations Conclusion and Recommendations Questions?

3. Standard Laser Tag Simulated gun combat using infrared beams Problems: Limited Strategy Limited Teamwork Repetitive Low Replay Value http://www.laser-tron.com/Laser_Tag_Library/Laser_Tag_KidsPlayingLASERTRON.jpg

4. Solution: Add Configurability! Ability to customize the game Create different gametypes & objectives Modify behavior of game devices Improvements: -Objective-Based Gameplay -Complex Tactical Strategy -Teamwork Required -High Replay Value Screenshot from Halo – Capture The Flag http://www.bungie.net/images/games/HaloPC/screenshots/halopc_deathisland_ctf.jpg

5. System Needs Basic laser tag functionality Wireless communication across devices Game scripting system Ability to script game Intuitive drag-and-drop GUI Robust compiler & linker Remotely initialize all game devices

6. System Needs Ability to play indoors & outdoors Minimal power usage (max battery life) Low consumer costs Low prototyping costs http://www.linksengineer.com/Admin/NewsImages/479a012f-fa62-45ac-9ae3-ae40d092dd32.JPG

7. Commercial Laser TagConfigurable Laser Tag Simulated gun combat Score Aggregation Objective-Based Play Configurable Devices Scriptable Gametypes Feature Comparison

9. Design Overview Two devices necessary for basic laser tag Tagger Necessary for tagging other players Transmits IR data Pack Necessary for sensing when a player is tagged Receives IR data

10. Design Overview In order to meet design objectives we need two additional devices Central Computer Keeps track of game state Enforces rules Communicates via RF Pylon Need stationary devices for players to interact with Functionality dependent on gametype

11. Scale of Project Four completely separate devices IR communication RF communication USB communication Scripting language Complex software running on all devices

12. System Communication

13. IR Communications Hardware Chose matching lens diameter and focal length Protocol Designed 23 bit IR packet Error Handling Added 6 bit hamming code for error correction TEAM IDPLAYER ID EVENT ID 40KHz Wave TSOP4840 IR Receiver TSAL6100 IR LED WPN DMG

14. RF Communication Hardware Using ONE-NET schematics Protocol Using ONE-NET protocol Allows multiple devices to share a single channel Uses acknowledgment packets to guarantee delivery

15. Scripting System Making scripting easy Think LabVIEW or Lego Mindstorms Basic structure Triggers & Primitives Basic logic How do we accomplish this? Internal representation? Interpreter?

16. Scripting System Example Example C code Equivalent Syntax Tree void takeDamage(int amount, int shooterId) { if(!isDead) { if (HP > amount) HP = HP - amount; else { HP = 0; die(shooterId); }

17. Scripting System Example Example Syntax Tree XML Representation

19. Implementing Scripting Have a back-end representation This must run on microcontrollers Need to convert XML to executable code

20. Implementing Scripting Drag-and-Drop GUI Abstract Syntax Tree (XML) XML Parser Compiler Linker Code Generation

21. Compiler & Linker Tasks Lexical Analysis / Parsing Preprocessing Semantic Analysis Linking within scripts Linking between multiple scripts Code generation Fix for microcontrollers Compiling is messy

22. Compiler & Linker Huge amount of work 4000+ lines of code Written in C++ Used only XML parsing library Completed!

23. Interpreter GUI: User-drawn nodes  XML script Compiler: XML script  Data structures Interpreter: Run data structures

24. Interpreter GUI: User-drawn nodes  XML script Compiler: XML script  Data structures Interpreter: Run data structures Low level code to run on microcontrollers Control devices based on script Primitives & Triggers Event infrastructure

25. Interpreter GUI: User-drawn nodes  XML script Compiler: XML script  Data structures Interpreter: Run data structures Programmer/Flasher?

26. Remote Programming Need to load scripts onto microcontroller via RF Central computer listens for new devices Send initialization data Keep list of active devices Interrupts must be disable while flashing Created packet request mechanism http://www.cisco.com/en/US/i/200001-300000/270001-280000/270001-271000/270121.jpg

27. Major Changes Changed wireless module to XBee Modules pre-built Protocol nearly identical to ONE-NET Switched from crystal oscillator to timer circuit Timer circuit far more reliable Switched microcontrollers twice First to consolidate to a single type of microcontroller Second to increase RAM and IO pins

28. Device Design – Central Computer

29. Device Design - Tagger

30. Device Design - Pack

31. Device Design - Pylon

32. Device Casing

34. Work Completed IR communication Protocol, software, and hardware RF communication Software and Hardware PCBs Pack Tagger Pylon Central Computer

35. Work Completed LCD interface High level scripting language Parser, compiler, and linker Ability to flash compiled script Script interpreter Remote procedural calls

36. Work Remaining System integration IR and timer code Power circuit Script gametypes GUI for admin and scripting front end

37. Problems Encountered BDM Programmer PCB Problems Vdd and Vss Footprints Power circuit Via sizes

39. Hardware Testing System testing Incomplete hardware Module testing Pack, Tagger, Central Computer, and Pylon Component testing ICs and passives

40. Demo Milestone Protoboard Demo Tagger Pack Central Computer RF, IR, LCD All working

41. Compiler Testing

43. Project Scale Project was huge 12 hours per week to start 48 hours per week for last 5 weeks Plus other classes!

44. Past Costs ItemCost LCD, 10 IR Leds, 4 IR recievers$25.80 RF Parts$12.59 PCBs over the summer$85.00 Breakout Board$12.49 PVC$12.24 USB controller$18.00 IR mounting$88.95 Crystals for IR$13.00 Shipping costs$17.14 TOTAL$285.21

45. New Costs ItemCost Final order from Digikey$112.00 Wires and connectors from pololu.com $141.47 Jameco - IR circuit & various parts$30.62 Final ordered PCBs$121.70 Final order from Mouser$109.21 Final order of LCDs$39.42 RadioShack Purchases$40.78 TOTAL$595.20

46. Cost to Others Oscilloscopes Power supplies Countless parts checked out Resistors Capacitors Programmer Soldering Iron Breakout boards http://hacknmod.com/wp-content/uploads/2008/10/oscilloscope.jpg

48. Safety and Ethics IR safety Low power RF safety Low power FCC approved bands Entertainment device Failure is not dangerous http://www.laserfx.com/BasicSafety/safety.gif

49. What We Learned USB communication and bus-power Send/receive encoded IR signals Send/receive encoded RF packets Design a language, XML parser, compiler and linker

50. What We Learned Solder SMT prototypes Efficiently design and layout circuits Conserve space Effective teamwork

51. Recommendations Do not tear down – make continual progress If possible, get components that run on the same voltage Do not try to re- invent the wheel http://209.169.12.51/images/products/08687-03-L_i_ma.jpg

52. Recommendations Compromise between low prototype cost and low product cost Remember: it is a prototype, not the end product Prioritize the essential parts Do not leave the power system until the end

53. Conclusion The Configurable Laser Tag System Introduces customizable objective-based gameplay Is a complex integration of Configurable devices Communication protocols Game scripting software

54. Conclusion If any one subsystem is not functioning, the system as a whole will fail to operate Despite the problems we encountered, we learned a lot, worked hard, and completed a significant portion of the work