1 / 25

Mobile Digital Audio Player Design Overview: A Comprehensive Review

This review presents a detailed overview of a mobile digital audio player designed to play FLAC audio files from a removable SD card. Key features include a lightweight design with a high-performance audio DSP, a 3.5mm headphone output, and an LCD interface for user interaction. We discuss the project-specific success criteria, innovative component selection rationale, and the project's packaging design. The schematic, theory of operation, PCB layout, and current software development status are also outlined, alongside the project timeline and discussion points for further questions.

isanne
Download Presentation

Mobile Digital Audio Player Design Overview: A Comprehensive Review

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ECE 477 Design Review Team 9  Spring 2009 Isaac Jones Brett Mravec Greg McCoy Danielle Miller

  2. Outline • 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

  3. 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

  4. 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.

  5. Block Diagram

  6. Component Selection Rationale • Considerations for all components • Lightweight • Low power consumption • Small size

  7. 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

  8. Component Selection Rationale

  9. 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 character-based, but not TV-quality either)

  10. 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!

  11. 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

  12. Schematic/Theory of Operation

  13. 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

  14. Schematic/Theory of Operation

  15. 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

  16. Schematic/Theory of Operation

  17. 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

  18. Schematic/Theory of Operation

  19. PCB Layout Constrained by enclosure!

  20. PCB Layout

  21. PCB Layout LCD header & trimmer pots Program Flash SPI to Parallel Shft.R 3.3 to 5 V Boost Reset Button SD socket SHARC Audio output amplifier and passives D/A Power circuitry

  22. 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

  23. 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

  24. 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

  25. Questions / Discussion

More Related