ECE 477 DESIGN REVIEW TEAM 7 SPRING 2013

COST ROBOT

CAROLINE TRIPPEL, ANDREW LOVELESS, ERIC OSBORNE, BRYAN DALLAS

Outline• Project overview • Project-specific success criteria• Block diagram• Component selection rationale• Packaging design• Schematic and theory of operation• PCB layout• Software design / development status• Project completion timeline• Questions / discussion

Project Overview• Design and build a compact robot to traverse a maze• Use the robot to generate an ASCII representation of the

entire maze• Mark light locations on map as they are discovered• Revisit lights intelligently

throughout the maze in a user-defined order

Project-Specific Success Criteria

• An ability to detect proximity to maze walls and prevent wall collisions.

• An ability to find specific locations in the maze based on the placement of colored lights.

• An ability to turn and change direction of movement. • An ability to generate an ASCII representation of the

explored maze. • An ability to transfer stored ASCII map to a GUI program

on a desktop computer via USB.

Block Diagram

Component Selection Rationale• Microcontroller: Microchip PIC18F4550

• Memory Size: 2048 Bytes RAM• 13 10-bit ADC Channels• 2 PWM• I2C• USB• 44 pins

• Fuel Gauge: Linear LTC4150• Simple setup, small circuit, easy monitoring

Component Selection Rationale• Digital Compass: Honeywell HMC6352

• I2C, easy setup, simple communication• Short Range Sensor: Phigets 1103_1

• Range: 0-100 mm (0-3.94 in)• Long Range Sensor: Sharp GP2Y0A02YK0F

• Range: 20 – 150 cm (7.87 – 59 in)• Color Light Sensor: Avago HDJD-S822-QR999

• 3 analog input for RGB, easy use

Component Selection Rationale• H-Bridge: Texas Instruments L293DNE

• Built in diodes for noise suppression• Geared Motor: Solarbotics GM3

• Small, provides enough power to push our robot without stalling• Digital Isolators

• Protects microcontroller from high motor voltage• 24MHz Oscillator

• Required for USB communication

Packaging DesignThree tiered octagon-shaped body:• Tier 1

• PCB, peripheral headers • Compass

• Tier 2• 3X short range proximity sensors• 1X RGB color sensor

• Tier 3• 1X Long range IR sensor• 2X DC Motors / Wheels• 1X 7.4V, 2 cell, Lithium-Ion Battery

Packaging Design

Packaging Design

Schematic

Microcontroller: PIC18F4550

Microcontroller: PIC18F4550

USB Connector

7.4V Battery Header / Fuel Gauge

7.4V Battery Header / Fuel Gauge

5V Regulator Circuit

5V Regulator Circuit

H-Bridge Driver / Motor Header

H-Bridge Driver / Motor Header

Digital Isolators

Digital Isolators

I2C Compass Header

Indicator/Status LEDs

Pushbuttons

A/D Sensor Input Header

24MHz Oscillator Circuit

24MHz Oscillator Circuit

Programming/USART Headers

PCB Layout

PCB Layout: Top Copper

PCB Layout: Bottom Copper

PCB Layout: 7.4V Power / Ground

= Ground = 7.4V

PCB Layout: 5V Ground

PCB Layout: 5V Power

Microcontroller / Headers

Motor Driver Subsystem

Power Subsystem

Oscillator Circuit

Pushbuttons

Sensor Header

Reset / Programming / Compass Header

Status/Indicator LEDs

Software Design

• Completed• USART for printing/debugging• PWM frequency/duty cycle control• Timing modules / interrupts• A/D conversion• Bidirectional USB communication

• Started• I2C, compass communication• Modified Tremaux Algorithm for maze traversal

Project Completion TimelineTask Week

8 9 10 11 12 13 14 15 16Base routines tested with peripheral hardware

X X

Robot base / motor construction

X X

Power prototyping / motion control

X X X X

PCB population / testing X X X

Robot construction X X X X X

Robot maze code X X X

USB/Maze display program code

X X

Final packaging / construction X X

QUESTIONS / DISCUSSION