Transcript ECE 477 Final Presentation Group ?? Fall 2004

ECE 477 Final Presentation
Group 6  Spring 2005
Eric Su
Mike Lowe
John Parlindungan
KamBiu Chan
Outline
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Project overview
Block diagram
Professional components
Design components
Success criteria demonstrations
Individual contributions
Project summary
Questions / discussion
Project Overview
• Arbuckle’s Automatic Pet Feeder
• Dream machine for every pet lover
• Deliver a controlled amount of food to 4 different
cats for up to 20 days without any user maintenance.
• Features
– RFID pet identification
– Remote monitoring through Ethernet
– Local user interface (LCD and RPG)
Block Diagram
Internet
PC
Microcontroller
I/O
I/O
SCI
User Interface
LCD
RPG
SCI
RFID
Reader
I/O
RFID
IR Level
Detector
Relay
Circuit
Ergos
Feeder
Professional Components
• Constraint analysis and component selection
rationale
• Patent liability analysis
• Reliability and safety analysis
• Ethical and environmental impact analysis
Constraint Analysis and
Component Selection Rationale
• Constraint Analysis
– Computation Requirement
• Speed
• Memory
– Interface Requirements
• SCI for LCD and RFID
• Ethernet connectivity
– Power Supply Constraints
– Packaging Constraints
– Cost Constraints
Constraint Analysis and
Component Selection Rationale
• Component Selection
Rationale
– Microcontroller
Freescale 9SHC12NE64
Rabbit 3000
Speed
25Mhz
54Mhz
Memory
64kb
256kb
Ethernet
Internal Transceiver
External Transceiver
– RFID Module
Series 2000 LF RFID
S4100 multi-function
Frequency
134.2kHz
134.2kHz – 13.56MHz
Range
15cm
12cm
Antenna
External
Internal
Constraint Analysis and
Component Selection Rationale
• Component Selection Rationale Cont’d
– LCD Display
CrystalFontz 634
CrystalFontz CFAH2004A
Interface
RS232 (serial)
8-bit or 4-bit (parallel)
Size
20x4
20x4
– Rotary Pulse Generator
• Grayhill 61C11
• Optical encoder with pushbuttons
• Small number of input pins
• Economy of space
– Pet Food Dispenser
• Augger style dispenser
Patent Liability Analysis
• Literal Infringements
– 4,510,495: Remote passive identification system
• Recommend to continue with development
• Doctrine of Equivalents Infringement
– 6,793,127: Internet enabled resource constrained
terminal for processing RFID tags
• Recommend to continue with development
Reliability/Safety Analysis
• 4 critical components analyzed
– Micrel 4690 Power Regulator – MTTF 105
years
– Grayhill 61C11 RPG – 1285 years
– Motorola MC9S12NE64 – MTTF 21 years
– Reed Relay Circuit – MTTF 190 years
• High criticality failures
– Voltage regulator power supply
– Reed Relay 120V Power Circuit
Ethical/Environmental Analysis
• Ethical Issues
– Protect electrical components from cats and human.
– SW updates through internet to correct any possible
firmware errors.
– Warning label on main board enclosure (Proper Care for
the Cats!!!)
– Low food volume alert
• Environmental Issues
– PCB fabrication (high material consumption) & disposal
(lead, hazardous waste)
• Dry plasma metal deposition
Design Components
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Packaging design considerations
Schematic design considerations
PCB layout design considerations
Software design considerations
Packaging Design
• Weight: 15 lbs
• Cost: $880.00
• Two Architectures
– Feeder Architecture
– Control Unit
Architecture
• Primary Considerations
– Safety
– Aesthetics
– Functionality
– Durability
Packaging Design
Packaging Design
Schematic Design
• MC9SHC12NE64
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Guarded with 0.22uF decoupling capacitors
BDM Port: For firmware update
ATD Port: IR sensor array
SCI Port: RFID reader, LCD
General IO: Relay
Timer Capture: RPG
Ethernet Port: Web access
Schematic Design
• Voltage Regulator
– 2 Step down regulators
– 12VDC unregulated input
– 5V and 3V DC regulated output
Schematic Design
• RS 232 Transceiver
– Interface 3.3V SCI ports to
external 5V serial
connection
– Provide health information
about the connections
Schematic Design
• RPG
– Optical encoder
– Standard Quadrature 2-Bit Code
– 8 Changes per revolution
• Relay control
– Optically isolated
– 120 AC Power Relay
– Power MOSFET switch with diode
Schematic Design
• IR Sensors
– 4 sensors monitoring 2 different levels of the food
container
– Output 0.1 – 2V
– Socket based for flexibility
PCB Layout Design
• 7.5” X 3.5”
• Trace width:
– 3.3V and 5V
GND and
Vcc rails:
50mils
– Normal
wires:
12mils
PCB Layout Design
• Decoupling caps for all ICs
• Copper pour under relay
• Separate power supply for
analog and digital system
• Physical isolation of the digital
and the analog system
Software Design
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State machine drives menu
Polling for RFID
All Others interrupt driven
Software Modules
– Timer_isr
– Rfid_isr
– Lcd_isr
– Button_isr
– Rpg_isr
– Update_web
Software Design
Software Design
Success Criteria Demonstrations
1. An ability to receive and decode RFID tags from the
cats
2. An ability to accurately dispense food for each cat
demo
3. An ability to remotely monitor the system via web
browser demo
4. An ability to interact with user via LCD display and
rotary pulse generator demo
5. An ability to alert on low food volume
Individual Contributions
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Team Leader – KamBiu Chan
Team Member 2 – Mike Lowe
Team Member 3 – Eric Su
Team Member 4 – John Parlindungan
Team Leader – KamBiu Chan
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PCB Layout Design
Patent Analysis
Schematic Design
Software Design and Testing (Peripherals)
Hardware Testing
Member 2 – Mike Lowe
• Design Constraint Analysis
• Software Design
– Main Program
– Ethernet
Member 3 – Eric Su
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Packaging Design
Reliability and Safety Analysis
Software Debugging and Testing
Team Webmaster
Member 4 – John Parlindungan
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Schematic Design
Ethical and Environmental Impact Analysis
Populating PCB
Hardware Debugging
Project Summary
• Important lessons learned
– Current Limiting Resistors!!!
– Debug Header is a MUST!!!
– Division of labor and individual
accountability
– Understand components’
soldering temperature limits
Project Summary
• Second iteration enhancements
– Sonar for inventory tracking
– Web administration capability
– Providing more than 1 kind of pet food
– Webcam
– Diet Log
Questions / Discussion