MP3toFM Midterm Presentation February 21, 2008

About Us 2 Brandon Leatherwood CPE/SE MCU Firmware Ethernet Design Josh Wilson CPE MP3 Decoder MCU Firmware Michael Weir CPE Server Setup MCU Firmware Lyn Hicks EE FM Transmitter Antenna Design

Overview Introduction Problem Problem Solution SolutionConstraints Technical Constraints Technical Constraints Practical Constraints Practical ConstraintsApproach Streaming Format Streaming Format Ethernet Controller Ethernet Controller Microprocessor MicroprocessorProgressQuestions

Problem Current products are restricted by portability, storage capacity, and sound quality. MP3 players MP3 players FM Transmitters FM Transmitters Wireless Ethernet Boom-boxes Wireless Ethernet Boom-boxes Home Audio Systems Home Audio Systems

Solution MP3toFM device Portable Portable Access to entire home PC library of audio tracks Access to entire home PC library of audio tracks Operates over Ethernet Operates over Ethernet

Technical Constraints Decoding Quality (Hardware) 64 kbps 64 kbps Re-encoding Quality (Server) Audio Quality bit depth of 16 bits, sample rate of 44.1 kHz bit depth of 16 bits, sample rate of 44.1 kHz FM Transmission Must be able to receive audio signal from 50 feet away. Must be able to receive audio signal from 50 feet away. FM Frequency Range 88 – 108 MHz 88 – 108 MHz

Ethical Concerns Stopping Illegal Music Sharing EULA EULA Password Protection Password Protection Digital Millennium Copyright Act Digital Millennium Copyright Act [1]

Political Concerns [2], [3] FCC Unlicensed BroadcastFCC Unlicensed Broadcast Regulations  250 µV/m at 3 meters  100 feet  Good Engineering Practice

System Diagram MP3toFM uP Ethernet Controller Streaming MP3 MP3 Decoder Raw MP3 FM Transmitter Antenna Analog Signal Control lines Data Flow

Server Software Server Software Server Software Features (Password Protection) Features (Password Protection) Icecast (General Public License version of Shoutcast) Icecast (General Public License version of Shoutcast) [4] Streaming Software Ezstream Ezstream [4] GPL GPL Easy to setup and configure Easy to setup and configure Winamp Winamp Proprietary (Allows for free distribution) Proprietary (Allows for free distribution) [5] More Features (Re-encoding) More Features (Re-encoding)

Streaming Format PCMMP3OggCompressedNoYesYes Hardware Design SimpleComplexComplex Licensing Fees NoYesNo Decoding Solutions ManyManyFew PCM - Pulse Code Modulation MP3 - MPEG-1 Audio Layer 3 Ogg - Ogg Vorbis

Alternative hardware Philips NXP LPC23xx (ARM7TDMI core) ASIX AX110xx (8051/80390 core) Pros Pros Cost effective ( manufacturing, horsepower ) Cost effective ( manufacturing, horsepower ) Open source market proven OS / TCP stack Open source market proven OS / TCP stack Lots of community support Lots of community support Cons Cons New architecture (learning curve) New architecture (learning curve) Higher development costs Higher development costs

Alternative hardware PIC18 with Ethernet Pros Pros Cost effective (manufacturing) Cost effective (manufacturing) Microchip provided TCP stack Microchip provided TCP stack Cons Cons Higher development costs Higher development costs Lack of OS Lack of OS

Chosen hardware Wiznet W3100 Hardware TCP stack Hardware TCP stack Fast Fast Generous buffers (16kB) Generous buffers (16kB) Cheap development costs Cheap development costsPIC24 More power / memory than PIC18 More power / memory than PIC18 Cheap development costs Cheap development costs Smaller learning curve Smaller learning curve

Progress  Streaming Format Identified  Microprocessor, FM transmitter, Networking Module, and MP3 Decoder Ordered  Block Diagram Created  Server GUI and Streaming Functionality Implemented

Remaining Tasks  Hardware Prototyping  PIC Firmware  SPI and I2C Slave Control  Packet Processing  Data Routing  Antenna Size Reduction

References [1] PoliTech. “RIAA declares war on Rap mixes,” February 16, [Online.] Available: [2] FlowTV. “A Critical Forum on Television and Media Culture,” February 16, [Online.] Available: [3] Federal Communications Commission. “47 CFR Part 15,” February 16, [Online]. Available: [4] Xiph Open Source Community. “Icecast,” [Online]. Available: Visited: February 21, [5] Winamp. “Winamp Legal Distribution Agreement,” [Online]. Available: Visited: February 21, 2008.

Questions?