Formal Design Review
Ryan McLean
John-Michael Mulesa
Joe Perrin
Zach Schoenberger
[Outline]
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Project Overview
Project-Specific Success Criteria
Block Diagram
Component Selection Rationale
Packaging Design
Schematic & Theory of Operation
PCB Layout & Considerations
Software Design & Development Status
Project Completion Timeline
[Project Overview]
• GPS-Based Head-Up Display
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Multi-mode driving aid
GPS navigation
Google Maps® (GSM chip)
Performance data
Color display
• Infinite focus
• Dashboard-mounted
[Proposed PSSCs]
1. An ability to display speed and elevation (obtained using
GPS).
2. An ability to display heading and G-force (obtained using
compass and accelerometer).
3. An ability to toggle map overlays (obtained via GSM
modem from Google Maps).
4. An ability to project a heads-up display focused at infinity.
5. An ability to change display brightness and vertical
position.
[Block Diagram]
Component Selection Rationale
Packaging Design
[Packaging Design]
• Size
– Plenty to pack inside!
– Limited external space
• Color
– Matte black
– Reduce/eliminate glare
• Material
– Aluminum construction
– Electronic components not affected
[Packaging Design]
[Packaging Design]
[Packaging Design]
[Packaging Design]
Schematic & Theory of Operation
[Schematic & Theory of Operation]
• GM862-GPS – GPS/GSM Unit
– 3.5V operation
– SCI connection to microcontroller
– Query-based data retrieval
• Query sent from microcontroller
• Formatted, query-based data returned
[Schematic & Theory of Operation]
• HMC6352 – Digital Compass
– 3.5V operation
– I2C connection to microcontroller
– Pass an address over I2C interface to listen to
compass module
[Schematic & Theory of Operation]
• ADXL345 – Accelerometer
– 3.5V operation
– I2C connection to microcontroller
– Pass an address over I2C interface to listen to
accelerometer
– Both accelerometer and compass are connected
to one I2C bus
[Schematic & Theory of Operation]
• FT232RL – USB to RS232 Adapter
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3.5VCCIO
5VCC
SCI connection to microcontroller
USB connection to ARM board
[Schematic & Theory of Operation]
• ATXMega16D4
– 3.5V operation
– 12MHz frequency
– Using:
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2 SCI buses
1 I2C bus
1 PWM
1 ADC
4 GPIO
PCB Layout & Considerations
[PCB Layout & Considerations]
Peripheral Considerations
• Keep I2C components close together
• Keep USB to RS232 IC close to USB connector
• Headers to access I/O traces
• Test points on power rails to quickly measure voltage
• GSM/GPS unit can draw 2A
– Uses direct connection to ground and power
– Assumes no vias
[PCB Layout & Considerations]
Microcontroller Considerations
• Locate microcontroller near middle of board
• Use 0.1μF decoupling capacitor for each
power-ground pair
• Small current draw
• Internal oscillator
[PCB Layout & Considerations]
Power Considerations
• Max current draw is about 2.2A
– Traces will have to be able to cope with current
draw
• Approximately 1.1mm traces
– Need sufficient bulk capacitance
– Minimize vias on power rails
Software Design &
Development Status
[Microcontroller]
• Polling the peripherals
– Timer interrupt driven polling of the peripherals
• Accelerometer
• Digital compass
• Control knob for mirror
– RTI driven peripherals
• All external buttons
• Controls Servo Motor
– PWM signal used to control servo to adjust mirror
– Based on change in Control Knob
• GSM Data
– Retrieves data constantly based on SCI interrupts
– Immediately signals ARM board and sends data
[Microcontroller]
• Interfacing with the ARM board
– Forwards data about peripherals upon request
• Based on custom instruction set over SCI
– ARM board can ask for data about specific peripheral
– Interrupt driven
– Forwards GSM data over SCI every time new data is
received
[ARM Board]
• Communicates with microcontroller to get raw
data
– Accelerometer, Digital Compass data
• Deals with all image manipulation
• Sends final image to projector
Project Completion Timeline
[Project Completion Timeline]
Week
Milestone
Items Due
8
• Package design to EE shop
• PCB, schematic revisions complete
Formal Design Review
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• Image display software started
• Microcontroller software started
• Projector ordered
Final PCB
Final Schematic
Proof-of-Parts
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Spring Break
11
• MCU-to-ARM communication
• Package complete
• Send/receive via GSM modem verified
• Receive GPS data verified
Software Design Narrative
12
• Image display software finished
• PCB assembled, tested
Patent Liability Analysis
[Project Completion Timeline]
Week
Milestone
Items Due
13
• External control functionality
• Projector, mirror mounted in package
Reliability and Safety Analysis
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• MCU, ARM mounted in package
• Initial “full-package” testing
Ethical and Environmental
Impact Analysis
15
• Dashboard mount fabrication
• Vehicle testing
• Final documentation
User Manual
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• Guest vehicle demonstrations
• Project complete
PSSC Demos
[Summary]
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Project Overview
Project-Specific Success Criteria
Block Diagram
Component Selection Rationale
Packaging Design
Schematic & Theory of Operation
PCB Layout
Software Design & Development Status
Project Completion Timeline
[Questions?]