Group 9: Infrared Based Interactive Laser Tag (IRILT)

IRILT Team

Jason Kazmar Jonathan Stoffer Chad Lau Ali Zaheeruddin Lets Do This

Project Description

Use infrared light to provide a safe, projectile-free combat simulator

Each team is assigned a different frequency, which, when modulated onto the IR beam, allows players to identify their attackers

Players may keep track of their vitals on an LCD screen Appropriate sounds are emitted to correspond with specific

actions Upon player death, an RF burst is sent over the playing field

to notify all other players When shot, system responds by providing visual and haptic

feedback

Project Overview

Embedded Atmel ATmega16L controls entire system To code the IR for two separate teams, the microcontroller

modulates two different frequencies (650 Hz and 1 kHz) onto a 38 kHz carrier frequency square wave

Fully addressable sound chip eases interfacing task System is powered by 4 ‘D’ batteries Removable clip allows user to reload rifle, causing LCD to

replenish ammunition supply (full clip = 30 rounds) IR sensors and feedback devices (motors and LEDs) are

implemented in a wearable vest and headband, with strategic placement to allow user to be attacked from all angles

Project Motivation

Create a realistic, yet safe, combat simulator that could be used by the military for training purposes

Like military equipment, IRILT equipment must be durable and reliable

More cost effective than paintball – hundreds of paintballs need not be purchased for each IRILT use and clothes will not be destroyed

More reliable than paintball - IR LEDs will not explode in barrel and thus render rifle useless

Block Diagram - Rifle

Microcontroller

DC Battery Supply

Cable to Vest

Antenna

TriggerTeam selectRemovable

Clip

IR out Speaker

SoundChip

RF in/out

Block Diagram - Vest

Cable to Rifle

IR sensors/demodulators

LEDs andVibrating motors

Headband with sensors,Motors, and LEDs

LCD on arm-band

Sensor Vest

Sensor and MotorPort (wired OR)

Constraint analysis/Component Selection

Microcontroller – Atmel ATmega16L 32 available I/O pins In system programmable FLASH 8 MHz clock Programmable Serial USART Straightforward development interface

(CodeVisionAVR: Programmable in C) Previous experience with Atmel μC’s


LCD – Crystalfontz

CFAH2004L-YYB-JP 4x20 Large viewing area (123.5 x

43.0mm) Small overall package size

permits use on wrist Simple to interface


Sound Chip – ISD2560P-ND 60 sec recording capacity 3.4 kHz Band Pass Filter Long lasting zero-power message retention (EEPROM): ~100

yrs. Fully addressable to handle multiple messages


RF Receiver – RXM433-LC

RF Transmitter – TXM433-LC-S Low current requirements

Receiver ~5mA Transmitter ~1.5mA

FCC Legal 433MHz Direct Serial Interface No complex antenna requirement


IR Transmitter – TSAL6100 High-powered IR LED Very short rise and fall time (800 ns)

IR Receiver – Panasonic PNA4602M 38 kHz band pass filter

(1 kHz 3dB rolloff) Insensitive to ambient light Requires no extra parts


Power Supply -MAX730A High efficiency 93% - 95% Guaranteed 450mA at 6V input 8 pin package Preselected external component

values, so no design work necessary

Patent Liability Analysis

Multiple patents have already been granted for laser tag games and laser tag equipment

Important existing patents: U.S. Patent # 5,741,185, 5,904,621, and 6,261,180

Patent # 5,741,185 – Interactive light-operated toy shooting game Toy gun emits coded light signal, which is detected by light

sensors Records number of hits and ends the game when appropriate “It is another object of the invention to provide a self-propelled

target whose motion is practically unpredictable during a game.” No literal infringement; no infringement under doctrine of

equivalents

Patent Liability Analysis (cont.)

Patent # 5,904,621 – Electronic game with infrared emitter and sensor Photodiodes are biased with an inductive current source

providing “substantially higher alternating current than direct current circuit impedance”

Specific coding placed into IR beams so that shot data may be distinguished from ambient light

No literal infringement; infringement under doctrine of equivalents Must pay royalty fees

Patent Liability Analysis (cont.)

Patent # 6,261,180 - Computer programmable interactive toy for a shooting game Has removable data modules for displaying player vitals on LCD

and uniquely coding IR transmission Each data module can be reprogrammed by a base station No literal infringement; no infringement under doctrine of

equivalents

Reliability and Safety Analysis

Microcontroller calculated to have shortest mean time to failure (MTTF) of ~23.65 years – Limiting Component

Mosfets MTTF calculated to be around 41 years All other components found to have well over one hundred years

MTTF DC-DC current mode switching regulator Phototransistors IR emitting diode RF receiving and transmitting modules LCD Panel

Criticality Levels High – The IRILT unit’s internal components have been damaged or

there is possible injury to the user Low – The IRILT unit will not function properly

Reliability and Safety Analysis

Ethical Impact Analysis

Safety Make it not look like a real gun Make sure there are no sharp edges that people

could hurt themselves on Sealed electronics

Marketed to Adults It is a simulated weapons system that should not

be targeted at children Other various warning labels

Environmental Impact Analysis

PCBs Can be harmful to the environmental Can be recycled

PVC piping Not biodegradable Like PCBs can be recycled

Alkaline Batteries Not considered Hazardous waste Can be recycled as well

Packaging Design Considerations

IR Rifle

IR diode

RemovableClip

BatterySupply

Trigger

Packaging Design and Considerations

Packaging Design and Considerations

Fully Suited (front) Fully Suited (back)

Schematic - LCD

No power needed for character display—powered through microcontroller

Power needed for contrast (controlled through potentiometer)

4 bit data, 3 bit instructions LCD Display = CFA2004AYYBJP

123456789

10111213141516

VCCR21POT

VDDVSS

R/WRSVO

DB1DB0E

DB3DB2

DB6DB5DB4

KADB7

IorD

GND

LCDEnableReadWrite

LCDdata6LCDdata5LCDdata4

GNDLCDLEDPOSLCDdata7

Schematic - Microcontroller

USART available for RF transmission and reception

Timer input-capture used for IR reception

Built in functions for LCD display

All floating pins were pulled low to prevent unexpected behavior

Atmel ATmega16L

Schematic changes - μC

Schematic – Sound Chip

MSBGND

SpeakerNegSpeakerPos

Sound Chip = ISD2560

VCCD28

CE'23

A89

A1/M12 A0/M01

A2/M23

EOM'25

A78

P/R'27

XCLK26

PD24A3/M3

4

A4/M45

A5/M56

A6/M67

A910

AUX IN11

VSSD12

VSSA13

SP+14

OVF'22

ANA OUT21

ANA IN20

AGC19

MIC REF18

MIC17

VCCA16

SP-15

R16 10k

GND

C220.1uF

C230.1uF

C2422uF

VCC

VCC

R175.1k

R18470k

C254.7uF

C260.1uF

PowerdownSoundEnable

GND

LSB

Schematic – Power Supply

Battery

Battery - 6V

12

VCCGND

C2168uF

C49

1uF

C50330pF

C510.01uF

C52

0.1uF

VCC

U15

MAX730A

SHDN'1

REF2

CC4

V+8

LX7

GND6

OUT5

SS3R13

510k

C20100uF

D4L233uH

Schematic - RF

Copper pour necessary to reduce EMI (electromagnetic interference)

RFrecvData

RFrecvPD

GND

U13

RF Recv

NC1

NC2

NC3

GND4

VCC5

PDN6

NC7

DATA8

ANT16

GND15

NC14

NC13

NC12

NC11

NC10

NC9

R15

200

E3ANTENNA

VCCGND

C47

10uF

DATA2 GND1

GND3

LADJ/GND4

GND8

VCC7

GND6

ANT5

RFtransData

R8430

E4

ANTENNA

11

VCC

C4810uF

PCB Layout

Traces for fast switching signals spaced apart from other lines to prevent EMI

RF devices placed far apart from switching voltage regulator Board size = 2.75” x 11”

Board must fit inside PVC piping Multiple headers for externally debounced switches

PCB Layout

PCB Layout

Multiplexer unused Not enough timer input-capture pins for multiple channels Wired-OR all sensors, LEDs, and motors together IR receivers wired directly to headers surrounding microcontroller

Audio amplifier unused Speaker wired directly to sound chip

Software

The software consists of 2 main parts A main loop 2 Internally controlled interrupts

Software Flow of Control

Triggerbutton

ClipButton

TeamButton

Check USARTBuffer (RF)

Shotfired

Clip Empty Fire ShotUpdate ammo(decrement)

Update ammoOn LCD

Produce GunSound

ClipAlreadyUpdated

Update ammo(ammo = 30)

Update ammoOn LCD

TeamAlreadyChanged

Update TeamFrequency

Update TeamName on LCD

Character inBuffer = ‘1’

Character inBuffer = ‘2’

Update LCD withPlayer 1 Died

Message

Update LCD withPlayer 2 Died

Message

yes no

no

yes

no

yes

yes

no

no

yes

yesno

no

yes

yes nono

no

yes yes

Interrupt Control FlowCall to

Hit detectISR

Capture TimeStamp

Pulses = 50

Return FlowOf Control

To main loop

CalculateFrequency

Update HealthCounter

(Decrement)

Update HealthBar on LCD

Update MessageOn LCD

Play Hit SoundHealth = 0

Play DeathSound

TransmitDeath Signal

TriggerButton

Reinitialize Unit

Call toGun Shot

ISR

Timer 2Output

On

Turn Timer 2Output off

Turn Timer 2Output on

Return FlowOf Control

To main loop

no yes

no

yes

yes

no

noyes

Demonstration

Project Success Criteria Ability to send, receive, and decode IR signals

Ability to send, receive, and decode RF signals

Ability to display player vitals in a visual user interface

Ability to generate sounds in response to actions

Ability to provide visual and haptic feedback

Jason Kazmar

Design Constraint and Analysis Component Selection

RF modules IR emitters/detectors Power supply

Schematic Populated Board Final Gun Package and Setup

Jonathan Stoffer

Ethical and Environmental Analysis Programmed and Debugged all

software Component Selection

Microcontroller

Ali Zaheeruddin

Reliability and Safety Analysis PCB Layout Schematic Packaged Vest and Feedback Sensors Component Selection

LCD Panel IR Transmitter Vibrating motors

Chad Lau

Component Selection IR Receiver Sound Chip

Packaging Design and Construction Troubleshooting hardware

What we learned

That excessive wiring definitely should be avoided How to layout a PCB Floating pins lead to unexpected and confusing results How to create and implement wireless technology (IR and RF) When creating a PCB layout, thicker traces should be used for

Vcc and ground All aspects of the design process, technical and professional How to read and analyze component data sheets What an RC time constant actually is Whenever ordering a replacement component at the last

minute, such as a microcontroller, it’s always a good idea to buy two just in case

IRILTV2 : Version 2.0

Possible implementation of RF in all components of IRILT system—Rifle and vest communicate through RF instead of wires, making IRILT less cumbersome

IR grenades, mines—One time, self contained IR emitting devices to increase battlefield tension and difficulty

Implement Muzzle Flash Replace IR with directional microwave Team select switch allows for more than two teams Optical scope on rifle “Smart” clip—Clip must be physically exchanged for another

when reloading Debouncing switches in software to minimize internal wiring

Questions?

IRILT

Group 9: Infrared Based Interactive Laser Tag (IRILT)

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Transcript of Group 9: Infrared Based Interactive Laser Tag (IRILT)