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Daniel MichelettiDarren AllenDaniel MazoJon LambLyle Johnson

Pixel PerfectWiCam: A Wireless Digital Camera

Presented by: Kyle Swenson

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Outline

• Design goals and challenges• Project design flow & starting point• Design process

– Product Prototyping– Microchip Synthesis & Fabrication– Verification & Integration– Software Security Implementation

and Interface• Results & conclusion

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Design Goals and Challenges

• Goal: … to design, fabricate and verify an integrated circuit (IC) that controls the SSLAR2 image sensor while adding wireless functionality and an LCD screen… and implement in a prototype security application

• Challenges– Multiple devices– Design complexity– Size limitation– Fabrication deadline– Interface definition for software

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Project Design Flow

Revise

Design

Test

Synthesis &Fabrication

Implement

Verify

Prototype

Expand

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Project Starting Point

Front View

Rear View

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Initial Product Design

microchip

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First Task

• Control and Communication Decoupling

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Device Selection: LCD

• 2.2” display– 176 x 220 pixels

• Only 4 control pins

• SPI

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Device Selection: Transceiver

• Datasheet specifies data range of 500 meters

• Bit transmission rate of 2 Mbps

• Very low power

• Just 5 control pins, SPI

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Generic SPI Module

Image ControllerStandardized

interface

DeviceController

Generic SPIModule

Standardizedinterface

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Device Prototyping: LCD

Initialize conditions

Limit area and write single color

Connect to system

Revise errors & finalize

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Device Prototyping: Transceiver

Receive Side Prototyping Transmit Side Prototyping

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First Revision

• Transceiver Limitations– Testing showed a distance of ~5 m– 2 Mbps is not sustainable

• Packet overhead• Distance considerations

• Transceiver Solution– Buffer the data

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Transceiver Backup Plan

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Implementation: Synthesis and Fabrication

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Integration: PCB Development

Layout Fabricated PCB

ReceiveBoard

TransmitBoard

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Verification: Chip and PCB

• FTDI bus contention

• Bidirectional pins– Inverted direction

• Two transistors cause of system-wide failure– 30,000 transistors total– 0.6 mm2

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Revision: Microsurgery

FIB areaX:0 Y:0

Microsurgery Request Microsurgery Results

Inverted direction signalInverter Bypass

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Verification: Pad Powering Problem

• Further testing showed critical pads not powered– Transceiver, DAC, LCD signals not present

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Revision: Backup Plan

• Implement design in FPGA

• Goal still accomplished

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Final Product

• Two Versions:– FPGA & SSLAR2 with software

interface definition– FPGA & SSLAR2 with wireless

transmission and LCD

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Software Interface Definition

• Define a hardware abstraction layer

• Use interface definition to create prototype security system

• Security System– Face Detection– Face Recognition– Motion Detection– Tablet web-based viewer

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Software: Tablet Web Interface

WAN/LAN

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Summary: Results

• Built the first revision of IC– Designed & Fabricated IC in 3 months– Implemented several backup plans as

needed to get design to work

• Built critical aspects of a complete security system

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Acknowledgements

• Dr. Suat Ay

• Anthony Kanago

• VLSI Sensors Research Group

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Questions?

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Backup Plan Block Diagram

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System Block Diagram

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Detailed Block Diagram (ASIC Core)

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FTDI Block

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USB State Machine