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)
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. - PowerPoint PPT Presentation
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Senior Design ProjectMid-Course Design Review
Wireless Home AudioAdvisor:
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
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 ~300ftDSSS
Direct Sequence Spread SpectrumStream of zeros and onesModulating with chipping sequence
Barker code 11 bits sequence of zeros and onesMathematical properties for ideal modulating radio wave
Stream data is XOR’d with Barker code to create chipEach 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 and Client Connection
Server
Opening a port
Make a connection Get port Get IP Address
*Send playlist
*Send MP3 file
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 communicationsocket(AF_INET, SOCK_DGRAM, 0)
Initialize own IP address and portaddr.sin_port = htons(12345)addr.sin_addr.s_addr = INADDR_ANY
MP3 filesCompress a CD-quality song by a factor 10-14Still maintain the good sound qualitySample rate 32kHz, 44.1kHz or 48kHzBit 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
Protel DXP- Circuit Design
Circuit Design Cont.
Circuit Design Cont.
Budget
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)
Problems and Solutions
ProblemsTINI
Bandwidth
Cost
SolutionsER22 (I2C)
Linux Bases ServerCLI w/ Server Code
40MHz PIC18 Family
Conclusion
SoftwareConnection (Server/Client)Send and Receive IP Packets (PING)Initialize chips over I2CControl the data flow to the decoder w/ bufferCustom UDP ProtocolWHAMP3 Web (SSID,Channel,WEP)