BLUETOOTH CONTROLLED HIGH POWER AUDIO AMPLIFIER

Presented By:

Bijay Raj Paudel (Roll No: 067/BEX/105)

Sagar Mali (Roll No: 067/BEX/133)

Sujan Shrestha (Roll No: 067/BEX/140)

Decent quality High Power Audio Amplifier

8051 Microcontroller based

Digital control over tone, effects & volume

Wireless Bluetooth Interface

Control via Computer Software and/or Keypad

INTRODUCTION

To construct cost effective audio amplifier.

To implement 8051 μc along with it’s interfacing.

To control the system via wireless Bluetooth module.

To program μc & develop GUI based PC application.

To improve our programming & practical skills.

OBJECTIVES

PROBLEM STATEMENTS & SOLUTIONS

Present Amplifier

Analog Control

Wired

Less Portable

No Display

Our Amplifier

Digital Control

Wireless

More Portable

LCD Display

METHODOLOGY

System is divided into two major parts :

Main Board

Remote and PC Interface

Main Board

Audio Input

Remote & PC Interface

Pre Amplifier

Optimizes signal

Reduces noise & disturbances

Includes multi Op-Amp stages and transistorized stages for low level signal amplification and filter

Brief Description of Main components

Power Amplifier

100 watt max class AB audio amplifier

Adjustable output transistor biasing to avoid crossover distortion

Overheat protection and short circuit output protection

Brief Description of Main components

Digital Potentiometers

• A digital potentiometer (informally a digipot) is a digitally controlled electronic component that mimics the analog functions of a potentiometer.

• It is used for trimming and scaling analog signals by microcontrollers.

Brief Description of Main components

8051 Microcontroller (AT89s52, AT89s2051)

256x 8-Bit Internal RAM

In-System Programmable (ISP) Flash Program Memory

– Serial Interface for Program Downloading

32 Programmable I/O Lines in s52 and 16 in s2051

Fully Static Operation: 0 Hz to 24 MHz

Programmable Serial UART Channel

Low Power Idle and Power Down Modes

Brief Description of Main components

EEPROM

Holds the data even when the power is removed

Used to save previous digital settings

Can also be programmed to hold custom

greeting messages

Brief Description of Main components

Bluetooth Module

Heart of the wireless data communication

Two TX and RX modules to be used

Transfers data to & from μc using UART protocol

Brief Description of Main components

MAX 232 IC (TTL to RS232 Convertor)

• Microcontroller logic levels 0-0.5 V and 4.5-5 V

• Max 232 circuit converts signal from RS-232 to 5 V TTLsignal level

• IC 7805 to provide power supply to MAX 232

Brief Description of Main components

Brief Description of Main components

RS232 to USB Convertor

Converts RS232 to USB signal

Makes the system more portable

Brief Description of Main components

LCD

Graphical LCD is planned to be used if available instead of normal alphanumeric LCD.

Ability to display custom sized fonts,

images and audio spectrum visualization

instead of just characters.

PC and GUI Control Application

Runs on OS of PC

Based on C# .NET

To change amplifier setting

Brief Description of Main components

Auditorium Hall

Seminar

Presentation

Lecture

Theatrical and Concert sound reinforcement

Home Theater System

Car Audio System

Guitar Amplification

APPLICATIONS

S.N. Item Unit Cost(Rs.) Quantity Total (Rs.)

1. Power Transistor 60 6 360

2. Microcontroller 150 4 600

3. EEPROM 200 1 200

4. Speaker (100 Watt) 1000 2 2,000

5. Bluetooth Module 1500 1 1,500

6. Digital Potentiometer 200 8 1,600

7. Audio Op-Amp 100 5 500

8. PCB Board 800 1 800

9. RS232 to USB convertor

1000 1 1,000

10. Others ~ ~ ~2,500

Grand Total ~11,000

COST ESTIMATION

TIME ESTIMATION

S.N. Title Estimated Time

1. Project Identification 1 week

2. System Planning 1 week

3. System Analysis 1 week

4. System Design 2 weeks

5. System Implementation 3 weeks

6. Troubleshooting 1 week

Total 9 weeks

CONCLUSION

Thus, our final product is going to be HIGH POWER AUDIOAMPLIFIER.

We expect to build BLUETOOTH INTERFACE between system &digital control.

Finally, it will have it’s own GUI BASED CONTROL APPLICATIONwhich can be operated through Bluetooth enabled devices.

BOOKS:A.S. Sedra and K.C. Smith, “Microelectronics Circuits Theory andApplication”, 5th edition, Oxford University Press

Muhammad Ali Mazidi, “8051 Microcontroller and Embedded Systems”,Prentice Hall, 2006

Douglas Self, “Audio Power Amplifier. Design Handbook”, 3rdedition.

WEBSITES:http://hackaday.com/2011/06/27/stereo-amplifier-with-digital-volume-control/

http://www.diyaudio.com/forums/solid-state/

http://en.wikipedia.org/wiki/Bluetooth

http://www.bluetooth.com/

REFERENCES

THANK YOU !