ECE 477 Design Review ECE 477 Design Review Group 7 Group 7 Spring 2005 Spring 2005

OutlineOutline• Project overview Project overview • Project-specific success criteriaProject-specific success criteria• Block diagramBlock diagram• Component selection rationaleComponent selection rationale• Packaging designPackaging design• Schematic and theory of operationSchematic and theory of operation• Preliminary PCB layoutPreliminary PCB layout• Software design/development statusSoftware design/development status• Project completion timelineProject completion timeline• Questions / discussionQuestions / discussion

Project OverviewProject Overview

An autonomous vehicle designed to look for An autonomous vehicle designed to look for

moving heat-emitting targets and engage them moving heat-emitting targets and engage them

while patrolling a limited area and avoiding while patrolling a limited area and avoiding

ground obstacles.ground obstacles.

+ =

Project-Specific Success CriteriaProject-Specific Success Criteria

• An ability to detect a heat-emitting targetAn ability to detect a heat-emitting target• An ability to determine and display the number An ability to determine and display the number

of engagements and battery levelof engagements and battery level• An ability to fire the weaponAn ability to fire the weapon• An ability to turn weapon to face targetAn ability to turn weapon to face target• An ability to avoid collisions with inanimate An ability to avoid collisions with inanimate

objectsobjects

Block DiagramBlock Diagram

FreescaleHC(S)12

(1)

Servo motor (1)

Passive IR sensors

(4)

Ultrasonic sensor (1)

LCD screen/Shift Register

(1)

AirSoft gun (1)

H-Bridge for Drive Motors

(1)

Component Selection RationaleComponent Selection Rationale

• MicrocontrollerMicrocontroller• Ultrasonic SensorsUltrasonic Sensors• Passive Infrared Sensors (PIR)Passive Infrared Sensors (PIR)• Robot BaseRobot Base• Liquid Crystal Display (LCD)Liquid Crystal Display (LCD)• Servo MotorServo Motor• Paintball GunPaintball Gun

Component Selection RationaleComponent Selection Rationale

• Micro-controller:Micro-controller: Motorola M68MOD912C32Motorola M68MOD912C32

- Pre-made DIP Module- Pre-made DIP Module

- Contains requisite I/O- Contains requisite I/O

- Instruction Set/Capability Familiarity- Instruction Set/Capability Familiarity

Component Selection RationaleComponent Selection Rationale

• Ultrasonic Sensors:Ultrasonic Sensors: Devantech SRF04Devantech SRF04

- Ease of use- Ease of use

- Small size- Small size

- Low cost- Low cost

Component Selection RationaleComponent Selection Rationale

• Passive Infrared Sensors:Passive Infrared Sensors: Kitsrus K30Kitsrus K30

- Easy to interface.- Easy to interface.

- Good range ( Approx. 120 degree spread )- Good range ( Approx. 120 degree spread )

- Low cost- Low cost

Component Selection RationaleComponent Selection Rationale

• Robot Base:Robot Base: Rogue Robotics RT-ATRRogue Robotics RT-ATR

- Easy to control ( 2 geared motors )- Easy to control ( 2 geared motors )

- Flexible/Expandable design- Flexible/Expandable design

- Multiple levels- Multiple levels

- Came with H-bridge- Came with H-bridge

Component Selection RationaleComponent Selection Rationale

• Liquid Crystal Display:Liquid Crystal Display: Optrex DMC20261A Optrex DMC20261A

- Free- Free

- 20 Chars x 2 Lines- 20 Chars x 2 Lines

- Backlit- Backlit

- Heavy-duty- Heavy-duty

Component Selection RationaleComponent Selection Rationale

• Servo Motor:Servo Motor: JR NES-537 JR NES-537

- Easy to interface/operate compared to stepper motor- Easy to interface/operate compared to stepper motor

- High torque rating ( 45 oz-in )- High torque rating ( 45 oz-in )

- Very small/lightweight- Very small/lightweight

- Low cost- Low cost

- 120 degree range- 120 degree range

Component Selection RationaleComponent Selection Rationale

• Paintball Gun:Paintball Gun: KTC 210910 KTC 210910

- Fully Automatic- Fully Automatic

- Electronic Trigger- Electronic Trigger

- Small ( 9” after cut down )- Small ( 9” after cut down )

- Light weight ( less than 1 lb )- Light weight ( less than 1 lb )

- Easily interfaced- Easily interfaced

Packaging Design – Front ViewPackaging Design – Front View

Packaging Design – Side ViewPackaging Design – Side View

Schematic/Theory of OperationSchematic/Theory of Operation

• Voltage regulatorsVoltage regulators• LCD interfaceLCD interface• PIR interfacePIR interface• Ultrasonic sensor interfaceUltrasonic sensor interface• Servo interfaceServo interface• H-Bridge and drive motors interfaceH-Bridge and drive motors interface• Gun trigger interfaceGun trigger interface• Battery level indicatorBattery level indicator

Schematic/Theory of Operation – Schematic/Theory of Operation – Voltage RegulatorsVoltage Regulators• Power supply for microcontroller module and Power supply for microcontroller module and

other digital components:other digital components:– Linear Tech LT1376-5 switching regulatorLinear Tech LT1376-5 switching regulator– Step down from 14.4 V input to 5 V Step down from 14.4 V input to 5 V

regulated outputregulated output– Can supply up to 1.25 A currentCan supply up to 1.25 A current– Up to 88% efficiency, typically around 86%Up to 88% efficiency, typically around 86%

Schematic/Theory of Operation – Schematic/Theory of Operation – Voltage RegulatorsVoltage Regulators• 10 10 H Inductor because the current draw could be H Inductor because the current draw could be

more than 0.6 Amore than 0.6 A

Schematic/Theory of Operation – Schematic/Theory of Operation – Voltage RegulatorsVoltage Regulators• Power supply for motors:Power supply for motors:

– Linear Tech LT1374-5 switching regulatorLinear Tech LT1374-5 switching regulator– Step down from 14.4 V input to 5 V Step down from 14.4 V input to 5 V

regulated outputregulated output– Can supply up to 4.25 A currentCan supply up to 4.25 A current– Up to 90% efficiency, typically around 88%Up to 90% efficiency, typically around 88%

Schematic/Theory of Operation – Schematic/Theory of Operation – Voltage RegulatorsVoltage Regulators• 10 10 H Inductor because the current draw could be H Inductor because the current draw could be

more than 3.5 Amore than 3.5 A

Schematic/Theory of Operation – Schematic/Theory of Operation – LCD interfaceLCD interface• Utilizes the SPI capability of the MCUUtilizes the SPI capability of the MCU• A shift register, 74HC164, will be used to register A shift register, 74HC164, will be used to register

data to be displayed on the LCD data to be displayed on the LCD • Pin PM5 will be used to supply SCK to the shift Pin PM5 will be used to supply SCK to the shift

register register • Pin PM4 will be used to supply SDO to the shift Pin PM4 will be used to supply SDO to the shift

register register • Pin PM3 will be used to supply RS to the LCD Pin PM3 will be used to supply RS to the LCD

modulemodule• Pin PM2 will be used to supply Enable to the LCD Pin PM2 will be used to supply Enable to the LCD

modulemodule• A 7x2 header will be used to connect LCD to the PCBA 7x2 header will be used to connect LCD to the PCB

Schematic/Theory of Operation – Schematic/Theory of Operation – LCD interfaceLCD interface

Schematic/Theory of Operation - Schematic/Theory of Operation - PIR interfacePIR interface• Four PIR (passive IR) sensors to detect heat Four PIR (passive IR) sensors to detect heat

emitting moving objects emitting moving objects • AN0 to AN3 will be used to receive the inputs AN0 to AN3 will be used to receive the inputs

from the sensorsfrom the sensors• 9 V pulse when a heat emitting moving target 9 V pulse when a heat emitting moving target

is detected is detected • A voltage divider is used to reduce the A voltage divider is used to reduce the

voltage input to the MCU to 5 Vvoltage input to the MCU to 5 V• Resistors with the values of 1 kResistors with the values of 1 k and 1.2 k and 1.2 k

will be used as the voltage divider will be used as the voltage divider

Schematic/Theory of Operation - Schematic/Theory of Operation - PIR interfacePIR interface

Vout = (RVout = (Rbelowbelow/(R/(Rupup+R+Rbelowbelow)) * V)) * Vinin

5 = (5 = (RRbelowbelow /( /(RRupup+R+Rbelowbelow)) * 9)) * 9

RRbelowbelow /( /(RRupup+R+Rbelowbelow) = 5/9) = 5/9

1.2 k1.2 k / (1k / (1k + 1.2 k + 1.2 k) ) 5/9 5/9

Schematic/Theory of Operation - Schematic/Theory of Operation - Ultrasonic interfaceUltrasonic interface

• PT7 will output trigger pulse to PT7 will output trigger pulse to the sensor the sensor

• PT6 will receive the input pulse PT6 will receive the input pulse from the ultrasonic sensorfrom the ultrasonic sensor

• Distance is determined by how Distance is determined by how long the input pulse is held long the input pulse is held highhigh

Schematic/Theory of Operation - Schematic/Theory of Operation - Servo interfaceServo interface

• Pin PT4 will be used to Pin PT4 will be used to output pulses regulated output pulses regulated by the built-in PWM to by the built-in PWM to the servo to rotate the the servo to rotate the gun turret gun turret

• Wiring setup image Wiring setup image courtesy of Parallax, courtesy of Parallax, Inc.Inc.

Schematic/Theory of Operation - Schematic/Theory of Operation - H-bridge and motors interfaceH-bridge and motors interface• PT0 to PT3, will be used as PT0 to PT3, will be used as

output pins to the H-bridge to output pins to the H-bridge to drive the direction of the robot drive the direction of the robot and PWM will be used to control and PWM will be used to control the speed of the motors the speed of the motors

• Drive motors will be connected Drive motors will be connected and powered through the H-and powered through the H-bridge bridge

• The power supply to the drive The power supply to the drive motors will be regulated by the motors will be regulated by the LT 1374-5 converter LT 1374-5 converter

• The H-bridge’s power will be The H-bridge’s power will be regulated by the LT 1376-5 regulated by the LT 1376-5 converter converter

• H-bridge image courtesy of H-bridge image courtesy of Rogue RoboticsRogue Robotics

Schematic/Theory of Operation - Schematic/Theory of Operation - Gun trigger interfaceGun trigger interface

• PM0 will be used as PM0 will be used as triggertrigger

• The gun will be optically The gun will be optically isolated from the MCUisolated from the MCU

• 4N28 opto-isolator will be 4N28 opto-isolator will be usedused

Schematic/Theory of Operation - Schematic/Theory of Operation - Battery level indicatorBattery level indicator• AN4 will be used to receive an analog voltage AN4 will be used to receive an analog voltage

reading from the power supply to indicate the reading from the power supply to indicate the current level of the battery current level of the battery

• 10-bit analog input and the analog to digital (A/D) 10-bit analog input and the analog to digital (A/D) converter will convert the input voltage to a digital converter will convert the input voltage to a digital value that can be used to compute the current value that can be used to compute the current battery level battery level

• Will be displayed on the LCD Will be displayed on the LCD • A voltage divider is used to reduce the voltage input A voltage divider is used to reduce the voltage input

to the MCU to maximum 5 Vto the MCU to maximum 5 V• Resistors with the values of 2.2 kResistors with the values of 2.2 k and 1.2 k and 1.2 k will be will be

used as the voltage dividerused as the voltage divider

Schematic/Theory of Operation - Schematic/Theory of Operation - PIR interfacePIR interface

Vout = (RVout = (Rbelowbelow/(R/(Rupup+R+Rbelowbelow)) * V)) * Vinin

5 = (5 = (RRbelowbelow /( /(RRupup+R+Rbelowbelow)) * 14.4)) * 14.4

RRbelowbelow /( /(RRupup+R+Rbelowbelow) = 5/14.4) = 5/14.4

1.2 k1.2 k / (2.2 k / (2.2 k + 1.2 k + 1.2 k) ) 5/14.45/14.4

Preliminary PCB LayoutPreliminary PCB Layout

Software DesignSoftware Design

TargetDetected?

DisplayEngagements

Poll PIR Sensors

Poll UltrasonicSensor

ObstructionDetected?

Turn MotorsON FWD

123

Turn 90o

Right

Turn MotorsOFF

Stop TurretFire

Weapon

SetEngagement

Flag

EngagementFlag Set?

IncrementEngagement Count on LCD

Pause for10 Seconds

ClearEngagement

Flag

Spin Grover180o

Turret SensorTriggered?

Turn Maxed?

Turn TurretRight

Turn TurretLeft

Stop/Reset Turret

Reset GunClear LCDStart

Which PIR Sensor?

Yes

YesTurn Motors

OFF

Yes

Yes

Yes

No

No

No

No

No

DisplayBattery Level

Spin Grover 90o

in Same Direction

Project Completion TimelineProject Completion TimelineWeekWeek Project CompletionProject Completion

88 - Finish PCB layout and fit parts to printoutFinish PCB layout and fit parts to printout- Receive final O.K. from Chuck Receive final O.K. from Chuck

99 SPRING BREAK (Gambling in VEGAS!)SPRING BREAK (Gambling in VEGAS!)

1010 - Start mounting parts to PCB - Start mounting parts to PCB

- Continue with software prototyping- Continue with software prototyping

1111 - Start interfacing software with hardware- Start interfacing software with hardware

1212 - Finish up on packaging with gun turret and servo motor mount- Finish up on packaging with gun turret and servo motor mount

1313 - Finish software interfacing- Finish software interfacing

- Begin working on user manual- Begin working on user manual

1414 - Finish user manual- Finish user manual

- Work on demonstration video and final presentation- Work on demonstration video and final presentation

1515 - Final Presentation- Final Presentation

Questions?Questions?