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

Hardware

ER22 kit

Printed Circuit Board (PCB) Content:STA013 MPEG 2.5 Layer III Audio Decoder

CS4334 D/A Converter for Audio

ER22 Wireless Kit

Microchip ICD 2 debugger

PCWH C compiler

MPLAB IDE- Convert C code to assembly language

MPLAB-ICD Header

MPEG Audio Layer III (MP3)

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)

HardwareResearch chips

Compatibility

Decision on chipsets

Getting parts (half)

Schematic Design

PCB layout

Final design