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Senior Design Project Mid-Course Design Review. Wireless Home Audio. Advisor: Professor Yngvesson, K Sigfrid Group members: Wan Ng (Hardware Protel) Eric Lajoie (Networking) Anish Shah (Software Client) Huy Nguyen (Software Server) Leonard Saint-Cyr (Hardware Calculations). Overview.
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Senior Design ProjectMid-Course Design Review Wireless Home Audio Advisor: Professor Yngvesson, K Sigfrid Group members: Wan Ng (Hardware Protel) Eric Lajoie (Networking) Anish Shah (Software Client) Huy Nguyen (Software Server) Leonard Saint-Cyr (Hardware Calculations)
Background • RTES (Real-Time Embedded System) • Wireless • Digital • UDP/IP (User Datagram Protocol/Internet Protocol) • Communication connection
Challenging Choice • Why did we chose the project? • Interesting • Wave of the future • Window of Opportunity • Major Challenges? • Wireless programming • Signal processing • Abstract • TINI wasn’t a good decision
802.11b (Wi-Fi) • Speed ~11Mbps • Distance ~300ft • DSSS • Direct Sequence Spread Spectrum • Stream of zeros and ones • Modulating with chipping sequence • Barker code • 11 bits sequence of zeros and ones • Mathematical properties for ideal modulating radio wave • Stream data is XOR’d with Barker code to create chip • Each bit is encoded by 11 bit Barker code and each group of 11 chips encodes one bit of data
UDP with Ad-Hoc • Fastest and most simple way of transmitting data • No interference in the stream of data • Provides the way to meet real-time • Better for multiple programs running on a single machine • Peer-to-peer connection
Server Opening a port Make a connection Get port Get IP Address *Send playlist *Send MP3 file Server and Client Connection • Client • Trying to make a connection • Connect to port • Send IP Address • Connection made • *Request playlist • *Request MP3 file *next semester
C code Programs Create socket, for communication • socket(AF_INET, SOCK_DGRAM, 0) Initialize own IP address and port • addr.sin_port = htons(12345) • addr.sin_addr.s_addr = INADDR_ANY
Hardware • ER22 kit • Printed Circuit Board (PCB) Content: • STA013 MPEG 2.5 Layer III Audio Decoder • CS4334 D/A Converter for Audio
Microchip ICD 2 debugger PCWH C compiler MPLAB IDE- Convert C code to assembly language MPLAB-ICD Header
MPEG Audio Layer III (MP3) • MP3 files • Compress a CD-quality song by a factor 10-14 • Still maintain the good sound quality • Sample rate 32kHz, 44.1kHz or 48kHz • Bit rate from 32kbits/s up to 448kbits/s
MPEG 2.5 Layer III Audio Decoder • Specifications: • Decodes Layer III Stereo channels, dual channel, single channel • 14.7456 MHz external input clock • I2C Control Bus (Serial Input Interface) • I2S (Serial Output Interface) • Bit rate and Sample rate
D/A Converter for Audio • Specifications: • Serial Input Interface • Complete Stereo DAC system: Interpolation • Over sampling Modes • Base Rate Mode (2KHz-50KHz) • High Rate Mode (up to 100KHz) • Bandwidth and Sample Frequency • Right/Left Audio Output
Items ER22 MP3 Decoder chips DAC chips PIC18 chips ICD2 Programmer CCS PCWH Books & Supplies Cost/Unit Budget – ($290x1) Free Samples – ($12x6) Free Samples – ($5x3) Free Samples – ($10x6) Dept. Cost – ($188x1) Dept. Cost – ($425x1) Personal Cost – ($210x1) Budget
Problems and Solutions • Problems • TINI • Bandwidth • Cost • Solutions • ER22 (I2C) • Linux Bases ServerCLI w/ Server Code • 40MHz PIC18 Family
Software Connection (Server/Client) Send and Receive IP Packets (PING) Initialize chips over I2C Control the data flow to the decoder w/ buffer Custom UDP Protocol WHAMP3 Web (SSID,Channel,WEP) Hardware Research chips Compatibility Decision on chipsets Getting parts (half) Schematic Design PCB layout Final design Conclusion