Let’s Have a Blast! Laser Tag Department of Electrical Engineering and Computer Science University of Central Florida Group 10 Marco Montero - Electrical Engineering Anuj Yamdagni - Computer Engineering Shannon Fies - Electrical Engineering Karlie Brinthaupt - Electrical Engineering Table of Contents 1.0 Executive Summary 6 2.0 Project Summary 7 2.1 Motivation 7 2.2 Goals and Objectives 7 2.2.1 Stretch Goals 8 2.3 Project Milestones 9 2.3 Project Budget/Bill of Materials 11 2.4 Game Mechanics 13 2.4.1 Main Gameplay Goals 13 2.4.2 Possible Gameplay Upgrades 13 2.5 System Flowcharts 15 2.5.1 Software Flowchart 16 2.5.2 Hardware Block Diagram 16 2.6 House of Quality 19 2.7 House of Quality Breakdown 21 2.7.1 Marketing Requirements 21 2.7.2 Engineering Requirements and Targets for Engineering 22 2.7.3 Engineering Requirement Relations 24 2.8 Team Collaboration Tools 25 3.0 Project Research 27 3.1 Similar Project Research 27 3.1.1 Arduino Laser Tag 27 3.1.2 University of Florida “Laser Tag Gaming System” 29 3.1.3 Pulse Modulated Laser Tag Game 29 3.1.4 Desired Elements from Similar Projects 30 3.2 Power Supply Research 31 3.2.1 Battery Technology 32 3.2.2 USB Charging 35 3.2.3 Battery Level Measurement 36 3.2.4 Voltage Regulator 38 3.2.5 Microprocessor Efficiency 40 3.3 Communications Research 41 3.4 Thermal Considerations 43 3.5 Serial Communication Research 44 3.5.1 UART 45 3.5.2 I2C 46 3.5.3 SPI 48 3.6 Software Development Model Research 51 4.0 Design Constraints and Standards 52 4.1 PCB Development 52 1 4.1.1 Soldering 53 4.2 Wireless Local Area Network (WLAN) Implementation 56 4.3 Realistic Constraints 58 4.3.1 Economic 58 4.3.2 Environmental 59 4.3.3 Social and Political 59 4.3.4 Health and Safety 60 4.3.5 Manufacturability 61 4.3.6 Sustainability 61 4.3.7 Ethical 61 4.3.8 Summary of Realistic Constraints 62 4.4 C++ Standards 62 4.5 Battery Standards 65 5.0 Project Design 70 5.1 Initial Parts Research and Design 70 5.1.1 Voltage Regulator Research 70 5.1.2 Battery Research 73 5.1.4 Vibration Motor 75 5.1.5 Trigger 77 5.1.6 LEDs 79 5.1.7 Display 80 5.1.8 Microcontroller vs FPGA 82 5.1.9 Microcontroller Selection 85 5.1.10 Audio Hardware Design 86 5.1.11 Peripheral Enable Line 87 5.2 Firmware design 88 5.2.1 IDE Software Options 88 5.2.2 Multitasking Implementation 89 5.2.3 Infrared Communication 91 5.2.4 Infrared Encoding 92 5.2.5 Wifi Mesh Networking 93 5.2.6 User Interface 94 5.2.7 Display Writing Algorithm 96 5.2.8 Serial Updating of Firmware 97 5.2.9 WiFi Based Updating of Firmware 97 5.2.10 Serial Based Debugging Interface 98 5.2.11 Standby Mode 99 5.3 ESP32 Pin Diagram 100 6.0 System Housing 104 6.1 Material 104 6.1.1 Shore Hardness 104 6.1.2 TPU (ThermoPlastic Polyurethane) 104 2 6.1.3 ABS (Acrylonitrile Butadiene Styrene) 105 6.1.4 PLA (Polylactic Acid) 105 6.1.5 PETG (Polyethylene Terephthalate - Glycol Modified) 105 6.2 3D Modeling Software 106 ​ 6.3 3D Model Design 107 7.0 System Testing and Demonstration 108 8.0 Prototyping 110 8.1 PCB Overview 110 8.1.1 Software and Manufacturer Choice 110 8.1.2 PCB Design 112 8.1.3 Final PCB Model 112 8.1.4 PCB Assembly Considerations 113 8.1.5 Terminology 114 8.2 Prototype Testing and Expectations 116 8.2.1 Hardware Testing and Expectations 116 8.2.2 Software Testing and Expectations 119 8.3 Component Testing 119 8.3.1 Power 120 8.3.2 Trigger 121 8.3.3 LED 122 8.3.4 Haptic Feedback 123 8.3.5 Infrared Transmitter and Receiver 123 8.3.6 Buzzer 124 8.3.7 Accelerometer and Display 124 8.3.8 Microcontroller 124 8.3.9 Wifi Mesh 125 8.4 Unit Testing 125 9.0 Conclusion 127 10.0 Appendix 130 10.1 Permission 134 3 Figure Index Figure 1 - Software Logic Flowchart………………………………………………..16 Figure 2 - Hardware Block Diagram ………………………………………………..17 Figure 3 - Group Breakdown………………………………………………………..18 Figure 4 - House of Quality…………………………………………………………..20 Figure 5 - RC Filter Circuit…………………………………………………………..27 Figure 6 - Amplifier Circuit…………………………………………………………...28 Figure 7 - Sensor Circuit……………………………………………………………..28 Figure 8 - UART Timing Diagram……………………………………….....………..45 Figure 9 - UART Serial Interface…………………...………………………..……...46 Figure 10 - I2C Timing Diagram……………………………………………………..46 Figure 11 - I2C Serial Interface……………………………………………………...47 Figure 12 - SPI Full Duplex Communication……………………………………….48 Figure 13 - SPI Interface with Individual Slaves…………………………………...49 Figure 14 - SPI Interface with Daisy-Chained Slaves……………………….…….49 Figure 15 - IPC Standards Tree…………………………………………………......53 Figure 16 - Holtek Voltage Voltage Regulator Application Circuit………….…....73 Figure 17 - TP4056 Application Circuit……………………………………………..75 Figure 18 - DW10A Application Circuit From PCB………………..…………...….75 Figure 19 - Vibration Motor………………...………………………………………...76 Figure 20 - Vibration Motor Application Circuit From PCB………………………..77 Figure 21 - Application Circuit of Trigger Mechanism from PCB……………..…..79 Figure 22 - LED Array Application Circuit From PCB……………………………...80 Figure 23 - OLED Application Circuit From PCB………………………………......82 Figure 24 - Speaker Application Circuit From PCB……………………………......87 Figure 25 - Bullet Encoding Layout………………………………………………….93 Figure 26 - Accelerometer Application Circuit From PCB……………………..….95 Figure 27 - ESP32 Development Board Pinout………………………………...…101 Figure 28 - 3D Model of Gun…………..……….…………………………………...107 Figure 29 - 3D Models of Trigger…………………………………………….....…..107 Figure 30 - Final PCB Layout………...………………………………………….….112 Figure 31 - Breadboard Testing………………………………………………….….125 Figure 32 - Protoboard Testing………………………………………………….…..126 4 Table List Table 1 - Senior Design 1 Milestones…………………………………………..…...10 Table 2 - Senior Design 2 Milestones……………………………………………….11 Table 3 - Budget/Bill of Materials…………………………………………………….12 Table 4 - Battery Type Comparison………………………………………………....35 Table 5 - Advantages and Disadvantages of Protocols…………………………...50 Table 6 - 3.3 V Voltage Regulator Voltage Characteristics……………………….71 Table 7 - 3.3 V Voltage Regulator Current Characteristics……………………….72 Table 8 - Rechargeable Lithium Battery Initial Parts Comparisons……………...73 Table 9 - Specifications of WS2812…………………………………………………80 Table 10 - Display Comparison…………………………………..………………….81 Table 11 - MCU vs FPGA Comparison……………………………………………..84 Table 12 - Microcontroller Comparison……………………………………………..85 Table 13 - Accelerometer Comparison……………………………………………..95 Table 14 - Requirements for Fusion 360………………………………………….106 Table 15 - Price Comparison of PCB Manufacturers…………………………….111 Table 16 - PCB Development Timeline……………………………………………118 5 1.0 Executive Summary As videogames and electronic devices become more and more popular, physical activity in kids is on the decline. Traditional games of tag or playgrounds can not compete with the allure of modern technology within videogames. Our team hopes to bridge that gap by combining technology with physical activity. Laser Tag has been a favorite of kids and adults alike, however it always seems to be limited to expensive arcades with limited game time. This project seeks to make laser tag available to more users at a lower price. By creating a cheap, standalone system that is easy to use, we can bring a fun technology that incorporates indoor and outdoor play. Our intended audience are kids and adults who are looking for casual entertainment that is not too expensive or difficult to set up. This sets up the project for several different requirements. The laser tag blaster will need to be a light, portable blaster so that it is easy to carry around and use. All the technology should be housed within the blaster, so that the blaster can be taken anywhere. Since kids will be using this blaster in outdoor settings, the outer shell of the blaster should be clearly identifiable as a toy and not a real weapon. Laser Tag is meant to be played with multiple people, thus the blasters should be able to synchronize with each other using a standalone network. The network should be a mesh network so that the group of players are not tied to any one location. The networking should allow the synchronization of game events such as the start and end of the game, as well as communicating the team score across to each player. Another important aspect of this project will be to include an easy to use User Interface (UI). This will allow users to create and join games easily and better immerse themselves in the gameplay. The blaster should include a small embedded display to show players information about the game, as well as a menu for setup. The blaster should include buttons for interacting with the menu. 6 2.0 Project Summary This section will go through an overview of the project and includes the following topics: ● Motivation ● Goals and Objectives ● Game Mechanics ● System Flowcharts ● House of Quality ● House of Quality Breakdown 2.1 Motivation Laser tag has been a favorite for kids and adults for many years, however there has been little development in the game to keep up with modern technology. Advances in smartphone technology has driven significant advances in embedded electronics, including networking, batteries, sensors and onboard computing power. However none of these advances in the smartphone technology have been applied to the game of laser tag. Not only has embedded technology significantly advanced over the past decade, the cost of embedded electronics has significantly dropped. We believe we can apply these advances to bring the game of laser tag up to date while making it much cheaper for people to play. 2.2 Goals and Objectives Hardware: Each gun’s electronics should be all contained onto a single PCB that ​ will be mounted within the shell of the gun.This will make assembly of the gun much simpler for mass production, as well as making testing each board easier as it will not require full assembly of the gun.