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 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: mm ( 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 Design Three 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

Schematic

Microcontroller: PIC18F4550

USB Connector

7.4V Battery Header / Fuel Gauge

5V Regulator Circuit

H-Bridge Driver / Motor Header

Digital Isolators

I2C Compass Header

Indicator/Status LEDs

Pushbuttons

A/D Sensor Input Header

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 Timeline TaskWeek Base routines tested with peripheral hardware XX Robot base / motor construction XX Power prototyping / motion control XXXX PCB population / testingXXX Robot constructionXXXXX Robot maze codeXXX USB/Maze display program code XX Final packaging / constructionXX

QUESTIONS / DISCUSSION