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WiFi Internet Radio (WiRAD)
Project Number: 109
Semester: Fall 2006
Project Keywords:
Internet Radio, Music Player, Audio Encoding/Decoding, Embedded Systems, Wireless, 802.11, MP3, OGG, RealAudio, Microprocessors, USB
The purpose of the following worksheet is to document the EE/CPE Design project, design team, and faculty mentor, prior to beginning the course.
1. High-level project description (problem solved by design and functionality).
This project proposes to free internet radio from being stuck in a home or office. One of the major obstacles that listeners must overcome in listening to their favorite internet radio stations is the lack of portability of the medium. In order to listen to a station, one needs a computer capable of connecting to the stream and playing over a set of speakers. For most listeners, this means that internet radio can only be enjoyed while he or she is actively sitting at a computer.
The WiRAD will attempt to break this restriction. The WiRAD device will allow a listener to hear his or her favorite internet radio station in any wireless hotspot. The device itself will handle all the wireless handshaking, so the listener does not need to worry about complex connectivity issues. The listener simply needs to have the URL of his or her favorite internet radio station and a ready set of ears.
2. A brief discussion of relevant technical background material on which the project is based (identify at least 3 published references).
The following reference provides a good general overview of streaming media, specifically in relation to windows programming:
[1] S. Mack, Streaming Media Bible, 1st. ed., New York: Hungry Minds, 2002
Streaming of raw CD-quality audio over the Internet is infeasible due to the density of such data. Consequently, all modern streaming technologies rely on audio compression. Compression techniques may be divided into two categories: lossless and lossy. Lossless techniques perform compression while maintaining all of the original data. An example of lossless compression may be found in the ubiquitous ZIP file format. In contrast, lossy compression techniques operate by removing unimportant aspects of the data. An example of lossy compression is the JPG image format. Lossy compression is a natural choice for audio data, as many subtle aspects of sound cannot be discerned by human hearing.
At the core of each of today's streaming audio technologies is a lossy audio compression algorithm. The four dominant compression algorithms are MP3, RealAudio, Ogg Vorbis, and WMA. Support for these streaming formats requires an in-depth understanding of each compression algorithm, and suitable related references will be required.
The following reference is an excellent overview of audio coding standards, such as .wav and .aiff, as well as an introduction to basic principles of streaming media:
[2] M. Bosi, R. Goldberg, Introduction to Digital Audio Coding and Standards, 2nd. ed., Norwell, MA: Kluwer, 2003
The following reference is an in-depth guide to MP3 format audio, including practical pseudocode for coding and decoding of MP3, as well as principles of streaming MP3:
[3] S. Hacker, MP3: The Definitive Guide, 1st. ed., Cambridge: O'Reilly, 2000.
The following reference will be used in the event that we choose to add the open source Ogg Vorbis audio compression format to the capabilities of our device. This reference includes practical pseudocode for coding and decoding of the Ogg Vorbis format:
[4] The Xiph Open Source Community, "Ogg Vorbis Documentation," 2005, http://xiph.org/vorbis/doc/ .
Implementation of streaming media capabilities on an embedded device requires detailed knowledge of the workings of TCP/IP and UDP/IP. A good reference on these transport and network layer protocols is:
[5] A. Tanenbaum, Computer Networks, 4th. ed., New Jersey: Prentice Hall, 2003.
3. Projects are evaluated, in part, on the inclusion of a number of the following "real-world" concerns. Provide preliminary comments on how these issues relate to your design.
Economic:
In the last few years mp3s and mp3 players have become a major part of pop culture. The internet is quickly becoming the number one delivery system for all media from video to music and even sporting events. In this new age of technology, everyone is constantly on the go. There has never been higher demand for information and entertainment. Most portable devices for consumers to use for internet content access are priced over $250. There are currently no low priced internet radio hardware solutions available to consumers. The product can introduce a whole new market for the entertainment industry. Sports fans can follow their team's game from anywhere with a wi-fi connection.
With WiRAD the consumer will have access an extremely low cost portable internet radio. The manufacturing cost will be kept under $70. Therefore the retail price for consumers can easily be kept under $100.
Environmental:
Sustainability:
Manufacturability:
This product can be manufactured quickly depending on part availability from suppliers. Our current estimate on manufacturing cost would be under $70 per unit. Startup costs for a manufacturing operation are conservatively estimated at $250,000, for a 350 unit per day production facility.
Ethical:
Health and Safety:
Social:
Political:
4. More detailed description of hardware and software design components (both hardware and software design are required for CPE students and both are strongly encouraged for EE students).
Hardware functionality:
• The device will connect via USB to a desktop computer for configuration.
• The device will include an internal radio for 802.11(b/g) wireless connectivity.
• The device will allow for volume control.
• The device will allow for seeking up and down the preset list in increments of 1 and 10 stations. While switching channels, audio notification of the preset number will be provided.
• The device will allow for resetting of network connection.
• The device will provide LED indicators for connectivity and activity.
• The device will provide a headphone jack.
Device firmware functionality:
• The device firmware will allow for configuration of preferred wireless networks, WEP keys, and preset channels over provided USB connection.
• The device firmware will utilize the provided internal radio to independently connect to nearby 802.11(b/g) wireless networks. Preferred networks and networks with strong signals will be given priority.
• The device firmware will decode and play MP3 format streaming audio.
• The device firmware will allow for the user interface requirements detailed in hardware functionality.
Desktop software functionality:
• The desktop software will facilitate USB connectivity to the device and provide for device configuration.
• The desktop software will allow for streaming of audio to the device.
Constraints:
• The manufacturing cost of the device shall remain under $70.
• The device shall have a battery life of at least 4 hours.
• The dimensions and weight of the device shall be such that it may be carried or worn comfortably.
• The quality of the streamed audio shall be comparable to CD-quality.
5. Vision for participation in project by team members.
Allen Taheri PCB Circuitry Design
Wesley Holland Hardware Abstraction Programming
Eric Tramel Encoding/Decoding Programming
Kirk Strong Power Systems
6. Preliminary schedule of what you are planning to do and discussion of feasibility.
June-July, 2006: Research, Feasibility, Initial Design
August-September, 2006: Hardware Prototyping, Audio Software Design/Implementation
October-November, 2006: Peripheral Connectivity, Hardware/Software Integration
December, 2006: Initial Testing
Spring, 2007: Finalizing Design and Implementation
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