1. Web Audio Stereo Component Group 3 Mike Foy Tony Camilli Barrett Cervenka Dave Hillyard

2. To Jog Your Memory.. 4 The market for high fidelity audio has always existed 4 High speed, dedicated Internet access is become more common in homes 4 Our project takes streaming audio via the Internet and makes it available as a stereo component

3. Our Project... Traditionally people have listened to the radio over and RF frequency. With our implementation, people will be able to listen to their favorite radio station no matter where they are in the world.

4. System Implementation 4 Four subsystems –User Interface –Network Interface –Audio Decoding Interface –Line Out Interface  Platform is a Motorola ColdFire 5307 processor running  CLinux

5. System Implementation

6. Subsystems 4 User Interface –User I/O –LCD panel –Buttons 4 Network Interface –Connectivity –TCP/IP protocol –High speed

7. Subsystems 4 Audio Decoding Interface –MPEG/Layer3 decoding 4 Line Out –Digital-to-Analog conversion –Audio signals outputted through RCA jacks

8. User Interface Implementation 4 Present several audio sources, then allow the user the select one 4 LCD Panel –Displays audio sources –Connected to parallel port on ColdFire board 4 Buttons –Used to select an option from LCD 4 Mainly hardware based, some software

9. Network Interface Implementation 4 Finds sources to pass to User Interface 4 After user has made a selection, the Network Interface makes a connection to the source and begins downloading bit stream 4 Connects to a LAN or other high speed Internet connection  Uses  CLinux running on ColdFire

10. Audio Decoding Interface 4 Takes incoming bit stream and converts it to digital audio 4 Uses MPEG/Layer3 decoding scheme 4 Decodes in real time, instead of downloading file completely, then replaying it.  Runs on  CLinux

11. Line Out Interface 4 Outputs the analog audio signal 4 DAC –Two-channel, serial input –Interfaces with  CLinux to receive digital audio –Converts digital audio to analog signal 4 Op-Amps - Conditions analog audio signal 4 RCA Jacks - Outputs analog audio signal on standard stereo connection

12. Software Design 4 Processes –LCD Output –MP3 Decoder 4 Interrupt Handlers –External Clock –Buttons

13. Software Design 4 Shared Memory –Audio Buffer –Shared Variables

14. Software Design

15. Processes 4 LCD Output –Reacts to shared variables –Variables change when buttons pushed and during decode process 4 MP3 Decoder –Connects to source –Downloads and decodes data

16. Interrupt Handlers 4 External Clock Interrupt –Fires at sampling rate of audio source –Reads data for Decode process from audio buffer –Tells DAC to output analog signal 4 Button Interrupt –Fires when a button is pushed –Updates shared memory

17. Shared Memory 4 Audio Buffer –Contains the audio data –Managed by Decoder process –On clock interrupt, next portion of data is removed 4 Shared Variables –Used for process communication –Written by Button Interrupt –Read by LCD and Decoder processes

18. Hardware Design 4 Embedded Processor 4 Evaluation Board 4 Project Board

19. Evaluation Board 4 Arnewsh SBC5307 Evaluation Board –Motorola ColdFire 5307 running at 90 MHz –8 MB Memory in SIMM stick –Integrated Ethernet controller –On-board RJ-45 port –I/O

20. Project Board 4 All extra hardware –Voltage buffers Converts voltage between 3.3 V and 5 V –LCD Panel –Buttons and de-bouncing circuits –DAC –Op-amps –RCA jacks

21. Approach to Implementation 4 Initial Proposal –Use RealAudio decoding –Implement on Motorola MCORE processor evaluation board 4 Revisions to Proposal –MPEG/Layer3 decoding –Motorola ColdFire 5307 processor-based Arnewsh evaluation board

22. Audio Format 4 Used ISO source as reference 4 Functions of the software –Decode bit stream –Output to parallel port to be converted 4 Some problems, however –No sound card –ColdFire has limited floating point support 4 Eventually found a solution

23. Network Interface Issues 4 Unsure of how to implement network communication 4 Several options –Implementing TCP/IP stack –Purchasing a proprietary RTOS with TCP/IP  Eventually found  CLinux

24. Linux Kernel 4 Linux kernel built with the software included 4 Resultant binary is downloaded to Arnewsh board 4 Significant problems with binary download, but was figured out after much experimentation

25. Final Version 4 Linux kernel with decoder 4 LCD process 4 Working digital-to-analog conversion 4 Unfortunately, without a device driver to interface with the DAC, cannot output analog signal 4 Using this driver, system is complete

26. Thanks to... 4 Dr. Mahapatra, for the encouragement and for never letting us forget when it was too easy 4 The TAs, for preparing us for Dr. Mahapatra’s impending comments and helping us with equipment 4 The ColdFire and Linux communities, for eager help when they had an answer to our questions

27. No thanks to... 4 Error-prone binary downloads 4 Bad documentation 4 Tools that didn’t work correctly 4 Not seeing the solution the first time

28. References... 4 Introduction to TCP/IP – –gopher://gopher- chem.ucdavis.edu/11/Index/Internet_aw/Intro_t he_Internet/intro.to.ip/gopher://gopher- chem.ucdavis.edu/11/Index/Internet_aw/Intro_t he_Internet/intro.to.ip/ 4 MPEG/Layer 3 Information –http://www.mp3tech.org 4 Motorola – –http://www.motorola.com

29. References... 4 WildRice –http://www.wildrice.com/coldFire/ 4 uClinux/ColdFire –http://www.moretonbay.com/coldfire/linux- coldfire.html 4 483 Home Page – –http://www.cs.tamu.edu/course- info/cpsc483/common/

30. References... 4 Analog Devices – – http://www.analogdevices.com

31. Questions?

32. Join us at the Dixie Chicken for a demonstration!