1. ECE 477 Design Review Team 13  Spring 2007
Greg Futia
Greg VonFange
Anirudha Bhende
Phil Kasper
Paste a photo of team members here, annotated with names of team members.

2. 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

3. Project Overview Waypoint Navigation Control System
Automated open field navigation
Equivalent to visual systems
User programmed GPS waypoints and route information
Demonstrate Feasibility by building system for R/C car

4. Project-Specific Success Criteria
An ability to
determine position and heading of the vehicle
enter and follow user programmable route
control the steer angle and speed of the vehicle
display heading and position information on a local LCD
stop and resume motion of the vehicle, if an obstacle blocks its path

5. Block Diagram

6. Component Selection Rationale GPS Selection
Selected Part: Garmin GPS 18
Accuracy WASS Capable
OEM Solution
Built in Antenna
Refresh Rate 5 Hz
Cost - $200
Competing Parts: SiRF III, U-Blox & Atmel, Magellan Engine

7. Component Selection Rationale Microcontroller
Selected Part: PIC18F2410
Low Pin Count
Built In Oscillator
C Development Tools
Availability of Development Tools in Laboratory
Lower cost of $2.24 compared with TI
Competing Parts: Freescale MC9S12UF32, TI MSP430F167

8. Component Selection Rationale Ultrasonic Sensor & Digital Compass
Ping Ultrasonic Sensor
Simple one pin Interface
Availability & Cost
Hitachi Digital Compass
Cost
Minimal Accuracy
Competing Parts: I2C Ultrasonic Sensor, OS3000, Dinsmore 1490

9. Packaging Design Considerations
Mounting
Protecting the PCB
Connectivity for the Motor Controller, Steering Servo, and GPS Unit
Port Holes for the Ultrasonic sensor
Mounting of the GPS Receiver
Opening for the LCD
Size

10. PCB Enclosure CAD Model
Packaging Design
PCB Enclosure CAD Model

11. Autocar Schematic Page 1
Power Supply

12. Autocar Schematic Page 2

13. Power System All components supplied by +5V
Low dropout regulator selected
310mV dropout at 500mA
All capacitors specified in data sheet

14. Garmin GPS Receiver Provides location, heading and speed information
Interfaces to microcontroller through DB-9 serial interface
User selectable baud rate
Interface will also be used for user programmability

15. Digital Compass
Provides heading data while stationary (limitation of GPS)
Interfaces through SCI to microcontroller
Provides 11 bit signed representations of x and y coordinates of compass
Motors may interfere with compass

16. Ultrasonic Sensor Used for obstacle detection
Single bidirectional signal
Small pulse triggers sample
Unit returns pulse on the same line
Microcontroller’s ‘interrupt on pin change’ used to detect returned pulse

17. LCD LCD used 4 or 8 bit parallel interface
4 bit interface can be used if resources are needed
3 GPIO lines used for control
Potentiometer included for contrast control

18. Motor Controller Interface
Drive motor controlled by commercial electronic speed controller (ESC)
Steering is controlled by servo motor
Interface to micro with 1 output pin each
Both receive same PWM signals to operate
Servo is powered by 5 V supplied by ESC

20. Software Design/Development Status
Motor Control Signals Complete
Center/Stopped
Right/Forward
Left/Reverse

21. Software Design/Development Status
Ultrasonic sensor module complete
8 inches
- Micro measured 1.1ms width. Sound travels at 1150 ft/sec
(1150 ft/sec * sec * 12inch/ft)/2 = 7.59 inches

22. Software Design/Development Status
LCD module in progress.
Code established, debugging
GPS module in progress.
Coordinates received using hyperterminal on PC.
Compass module in standby.

23. Project Completion Timeline

24. Questions / Discussion