Roboat Final Presentation

Jonathan FriedmanDave MaccaferriJosh McKenna

Chris Wieczorek

Roboat Project Goals

Features•1 PIC18F452, 2 PIC18F252 Embedded Microcontrollers

•50x50 pixel, 4 bit color Digital Camera

•Onboard Digital Compass and GPS Unit

•19,200 baud Serial Data link

•Windows GUI Interface

The Roboat platform is intended to be an autonomous robotic system for marine application in

both the government and commercial sectors.

Percent Completed

86%

100%

100%

100%

95%

Embedded Systems-Overview

Embedded Systems-SchematicPNI Vector 2x Digital

Compass

LM2940 V

oltag

e R

egulator

PIC18F452 Navigation and Host

PIC18F252 Modem

PIC18F252 GPS & Camera

Gameboy Camera and Maxim 114 A/D

Mas

t H

eade

rs

DIP Switches

Maxstream XStream Modem

GPS

RS-232 Breakout

Embedded Systems-PC Board

PC Board-Top PC Board-Bottom

•Layout from OrCAD schematic

•Routing preformed by OrCAD and by hand due to density of board

•537 holes, 60 feet of trace, 67 parts in a minuscule 27 square inches

•PCBoard fabricated by PCBExpress- $100, 24 Hour completion

Embedded Systems-MicroControllers

Modem Controller PIC18F252

Camera & GPS Controller PIC18F252

Navigation & host Controller

PIC18F452

2.5 Mhz (6.25Mbps)

interrupt driven,

random initiation,

single-point arbitrated,

Serial Peripheral Interface (SPI)

on-boat data bus among 4 devices (PIC’s + Compass).

CAMERA

MODEM

GPS

PIC#2: SLAVE

PIC#3: SLAVE

PIC#1: MASTER

CommandConsole

GPS & camera data stream limited to once per second (~5ms bus transfer time) by

PIC#2

Termination point for navigation data.

Telemetry generation point.

Data packing and processing.

Fully asynchronous communication

Scheduled (generation limited)Unscheduled (random arrival)

Embedded Systems-On Boat Data Flow

• Scheduled production of output (Compass)• Bandwidth limited production of output (GPS,

Camera)• Feedback-based flow control (buffer overflow

interconnects among PIC’s)• Panic data loss (Ability to give up on this data

and just look for the next)• Hardware flow-control and buffering (Modem,

PIC#2, PIC#3)

Embedded Systems-Mechanisms of Bus Arbitration

Physical Boat

Physical Boat-Under the Cabin

LED Mast

27MHz / Microcontroller Switch (hidden)

Push Button Toggle Switch (hidden)

Gameboy Camera

Physical Boat-Under the Deck

Video

Video

• Specifications– Analog Output– 8-bit (256 Colors) Capable

• 4-bit depth used

– Works with A/D converter to interface with PIC

• Functionality– Image Acquisition– Streaming Video (1 fps)– On-the-fly adjustable Gain

and Exposure Settings

Video

• Initial Images Stages

• Improved 32x32 Resolution Pictures

• Improved 50x50 Resolution Pictures

Video

• Camera Mounting and Cabling

Navigation

Navigation

Properties:• SPI

• Calibrates for constant magnetic fields

• Binary Output

• Fast settle time (5 Hz)

Functionality:• Heading changes

• Check GPS heading data

Navigation

• MACRO driven– 3 major turns and 1

corrective turn per side– Heading relayed from

GPS every second• This guarantees accurate

comparisons between the waypoint heading and current heading

– Averages 3 heading readings when running straight

• Counters the boat rocking

(continued)

+90-90

+45-45

+15-15

+5-5

Waypoint Heading

Hard LeftHard Right

Med LeftMed Right

Light LeftLight Right

Corrective LeftCorrective Right

Straight

180

SPI/RF Protocol

Byte 0 Byte 1 Byte 2+ Byte n-1 Byte n

FF 01FE XX* FF 00

Data Esc Opcode Data Data Esc Stop TX

Example packet: Panic StopFF 21 00 FF 00

GUI

•Multithreaded Windows Application

•Ability to command Roboat.

•Display Roboat telemetry data.

•Calculate the heading to a waypoint and then transmit it to the Roboat

•Display images from the onboard camera.

•Provide a waypoints list.

Project Management

•A Yahoo group was used for group collaboration

•Tasks where segmented according to core competencies.

•Hardware/software was codeveloped.

•More than 150 e-mails were sent among group members

•The team found that the Lab space was lacking in basic engineering tools such as millimeters, DC Power supplies, and oscilloscope probes, solder stations, and mechanical tools. An entire 3042 lab setup would have been useful.

Updated Gantt Chart