Transcript ECE 477 Final Presentation Group ?? Fall 2004

ECE 477 Design Review
Team 9  Spring 2009
Isaac Jones
Brett Mravec
Greg McCoy
Danielle Miller
Outline
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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
Project Overview
• Mobile digital audio player
• Plays FLAC audio files stored on a
removable SecureDigital (SD) card
• Synthesizes the sound data to a 3.5mm
headphone jack
• LCD Display and buttons for user input
• Integrated lithium Ion battery and on-board
charging circuit
Project-Specific Success Criteria
• An ability to decode files stored in the FLAC
format
• An ability to select files stored on the device
• An ability to display visualization information
• An ability to output audio to a headphone or
speaker port
• An ability to pause and resume playback on
user input.
Block Diagram
Component Selection Rationale
• Considerations for all components
– Lightweight
– Low power consumption
– Small size
Component Selection Rationale
• Audio DSP
– Sufficient processing capabilities
– Easy audio interfacing
– SPI interface for SD card and other
peripherals
• D/A
– High performance for audio
– Easy to interface to DSP, or built-in
Component Selection Rationale
Analog Devices
ADSP-21991
Clock
Program Memory
Data Memory
Digital I/O
Audio Capability
Analog Devices
ADSP-21262
Freescale
DSP56362
160 MHz
512 kb
256 kb
1 SPI, 1 UART
On-board A/D and
PWM D/A
100 MHz
720 kb
120 kb
1 SPl / 1 Parallel
Onboard DAI with
I2S and S/PDIF
Package
Development
Tools
200 MHz
4 Mb
2 Mb
1 SPI / 1 Parallel
On-board 6
channel serial DAI
(w/ I2S)
176-LQFP
144-LQFP
Not available, very Available already
new product
on campus
Cost
$26.36
144-LQFP
Available for
similar
processors
$7.40
$18.01
Component Selection Rationale
• LCD & Battery two largest
components
• Both need to be extremely
thin
– 15 mm allowance for LCD
& Li-Ion battery
– 8.9 mm LCD + 5.8 mm
battery = 14.7 mm
• LCD preferably graphics
capable (not characterbased, but not TV-quality
either)
Packaging Design
• Off-the-shelf enclosure
• Larger than competitors such as
the iPod and Sandisk Sanza, but
still highly portable
• Very tight tolerances for parts fit!
Schematic/Theory of Operation
• Digital Signal Processor
– Analog Devices ADSP-21262
– 144 Lead LQFP
– Visual DSP++ Debugger & Evaluation Board
• Program Flash memory
– Atmel AT25F2048
– 2 Mbits in 8 bit words
– Used to store Instruction Memory
• SD Card socket
– User interface for loading FLAC files
Schematic/Theory of Operation
Schematic/Theory of Operation
• LCD Screen
– Crystalfontz
CFAG12864B-TFH-V
– Built-in LCD Controller
– 128x64, B&W
– VIN minimum = 3.5 V
– SHARC can only
guarantee 2.4 V
• Level Translators
– TI CD4504B, 3.3 V to 5 V
– For interfacing 3.3 V
SHARC to LCD and D/A
Schematic/Theory of Operation
Schematic/Theory of Operation
• Digital to Analog Converter
– Analog Devices AD1854
– Delta-sigma type
– Accepts 16/18/20/24 bit data; 96 kHz sample rate
– I2S communication Protocol
– 5 V, but 3.3 V input tolerant
• Audio Operational Amplifier
– Analog Devices SSM2135
– Used as headphone amplifier/buffer with low pass
filter
Schematic/Theory of Operation
Schematic/Theory of Operation
• Voltage Regulators
– Design Requires 3
Voltage levels
– 5.0V provided by Linear
Technology LT1302
– 3.3V provided by Texas
Instruments TPS63030
– 1.2V provided by
AME8890
• Coulomb Counter
– LTC4150 Battery Gas
Gauge
– Interrupt-Driven
Operation
– Provides capacity to
monitor bi-directional
charge flow.
Schematic/Theory of Operation
PCB Layout
Constrained
by enclosure!
PCB Layout
PCB Layout
LCD header & trimmer pots
3.3 to 5 V
Boost
SPI to
Parallel
Shft.R
Program
Flash
Reset
Button
SD socket
SHARC
Audio output
amplifier and
passives
D/A
Power circuitry
Software Requirements:
• FLAC decoding
– Already implemented in C
• Most peripherals interface with SPI
– Flash memory
– SD Card
– LCD Controller (special case)
• D/A interface with I2C Serial
• Visualization Computation
Software Design – Other
Functions
Timer-Based Functions
• LCD Screen Update
• Output decoded data to D/A
Interrupt-Based Functions
• Coulomb Counting
• User push-button interrupts
Miscellaneous Functions
• Requesting new data block from SD Card
• Computing visualization information
Project Completion Timeline
• 25 March - Power circuitry functional (stable
power supply, burn-in complete)
• 1 April - DSP “Heartbeat” established,
software loading functional
• 3 April - Audio output circuitry complete
• 8 April - FLAC decoding software functional
• 10 April - LCD hardware & software functional
• 17 April - Able to read files from SD Card
• 24 April - All PSSCs implemented
Questions / Discussion