Chapter-1

A

Major Project Report on

MICROCONTROLLER ENABLED SPEAKING SYSTEM FOR DEAF AND DUMB

Submitted to

RAJIV GANDHI TECHNICAL UNIVERSITY

BHOPAL (M.P)

In Partial fulfillment for award of degree of

BACHELOR OF ENGINEERING

INELECTRONICS & COMMUNICATION

By

SARVESH SHASTRI

SOURABH DUBEY

SUJIT SINGH

SARVESH BATRA (0187EC101093) (0187EC101103)

(0187EC101106)

(0187EC101092)

Under the Guidance of

MOHD.ABDULLAH

SAGAR INSTITUTE OF SCIENCE &TECHNOLOGY (SISTec)

GANDHI NAGAR, BHOPAL-462036 (M.P.)MAY-2014SAGAR INSTITUTE OF SCIENCE AND TECHNOLOGY

(Approved by AICTE Delhi, Affiliated to RGTU Bhopal and Govt. of Madhya Pradesh)NEAR AIRPORT, GANDHI NAGAR, BHOPAL-462036

DeclarationWe hereby declare that the project entitled MICROCONTROLLER ENABLED SPEAKING SYSTEM FOR DEAF & DUMBis the actual work carried out by us in the department of ELECTRONICS & COMMUNICATION under the guidance of MOHD. ABDULLAH.Name

SARVESH SHASTRI

SOURABH DUBEY

SUJIT SINGH

SARVESH BATRA

Enrollment Number

(0187EC101093)

(0187EC101103)

(0187EC101106)

(0187EC101092)Signature

.

.

..

..

SAGAR INSTITUTE OF SCIENCE AND TECHNOLOGY

(Approved by AICTE Delhi, Affiliated to RGTU Bhopal and Govt. of Madhya Pradesh)NEAR AIRPORT, GANDHI NAGAR, BHOPAL-462036

CERTIFICATEThis is to certify that the project entitled MICROCONTROLLER ENABLED SPEAKING SYSTEM FOR DEAF & DUMB has been carried out by

Under my guidance in partial fulfillment for the award of (BACHELOR OF ENGINEERING) in ELECTRONICS & COMMUNICATION by the Rajiv Gandhi Technical University, Bhopal (M.P.), during the academic year 2013-14.DR. RAVI SHANKAR MISHRA

MOHD. ABDULLAHAssistance Professor & Head of

Project Guide Department of Electronics & Communication(Dr. Manish Billore)PrincipalSAGAR INSTITUTE OF SCIENCE AND TECHNOLOGY

(Approved by AICTE Delhi, Affiliated to RGTU Bhopal and Govt. of Madhya Pradesh)NEAR AIRPORT, GANDHI NAGAR, BHOPAL-462036

ACKNOWLEDGEMENTS It gives me a great pleasure to express my deep sense of gratitude and indebtedness to my guide MOHD. ABDULLAH for their valuable support and encouraging mentally throughout the project. I am highly obliged to them for providing me this opportunity to carry out their ideas and work during my project period and helping me to gain the successful completion of my Project.My special thanks to Head of the Department of Electronics & Communication Engineering of my college, Dr. Ravi Shankar Mishra and to all of the faculties for allowing me and encouraging me constantly to work hard in project.

I am highly grateful to the Honorable principle of SISTec, Dr. Manish Billore, for giving me this golden opportunity to be a part of this organization for this period.

Name

Enrollment Number

Signature

SARVESH SHASTRI

0187EC101093SOURABH DUBEY 0187EC101103SUJIT SINGH

0187EC101106SARVESH BATRA

0187EC101092 INDEXAbstract (i)

List of Table (ii)

List of Figure (iii)

1 INTRODUCTION 1.1 GENERAL 51.2 BLOCK DIAGRAM 61.3 VOICE DRIVER CIRCUIT 71.2.1.1 MICROCONTROLLER 8

1.2.1.1.0 MEMORY ORGANIZATION

VOICE MODULE 132 Literature Review2.1Microcontroller Devices 15

3 Methodology 17 3.1 LAYOUT DESIGNING 17 3.2 IRONING 18 3.3 ETCHING 19 3.4 DRILLING 20 3.5 SOLDERING 214 EMBEDDED C CODING 22-235 RESULT 246 CONCLUSION 258 REFERENCE 26Micro controller based speaking system for deaf and dumb is designed to give the signs, which are preloaded in the device. It is a micro controller based device, which gives the alert sounds just by pressing the control buttons, which are given some redefined messages like asking for water, washroom etc., here the person can just press the control button which indicates the sign of water (example) then the device sounds the same with some output volume.

Micro controller is the heart of the device. It stores the data of the needs of the person. So that it can make use of the data stored whenever the person uses the device. This device helps the deaf and dumb people to announce their requirements. By this the person who is near can understand their need and help them. This saves the time to understand each other and ease in communication.

This device is designed to provide with a greater advantage producing voice based announcement for the user i.e. the user gets the voice which pronounces his need as and when it is required.Table No.Table NamePage No.

1.7805 MODE26

Block diagram of speaking microcontroller FIG 1.1 Page no. 6Voice driving circuit .. FIG 1.2 Page no. 7LED .FIG 1.3 Page no. 7

SWITCHES. FIG 1.4 Page no. 77805 voltage regulator IC. FIG 1.5 Page no. 8

Architecture of P89V51RD2BN.. FIG 1.6 Page no. 9

PIN diagram of P89V51RD2BN.. FIG 1.7 Page no. 10PIN diagram of voice modular IC FIG 1.8 Page no. 14Layout design of speaking microcontroller FIG 1.9 Page no. 17

Ironing process. FIG 1.10 Page no. 18

Etching process FIG 1.11 Page no. 19Drilling process. FIG 1.12 Page no. 20Soldering process. FIG 1.13 Page no. 21Microcontroller enabled speaking system for deaf and dumb.. FIG 1.14 Page no. 24

1 Introduction1.1. General Micro controller based speaking system for deaf and dumb is designed to give the signs, which are preloaded in the device. It is a micro controller based device, which gives the alert sounds just by pressing the control buttons, which are given some redefined messages like asking for water, washroom etc., here the person can just press the control button which indicates the sign of water (example) then the device sounds the same with some output volume. Micro controller is the heart of the device. It stores the data of the needs of the person. So that it can make use of the data stored whenever the person uses the device.This device helps the deaf and dumb people to announce their requirements. By this the person who is near can understand their need and help them. This saves the time to understand each other and ease in communication his device is designed to provide with a greater advantage producing voice based announcement for the user i.e. the user gets the voice which pronounces his need as and when it is required. The main features of this project

1. User-friendly interaction with the use.

2. Reliable for dumb people.3. Easy to operate.This project provides learnings on the fallowing advancements:1. Characteristics of micro controller.

2. Building audible tone generating circuit.

3. Voice generation circuit.

4. Embedded C programming.

5. PCB design.

The major building blocks of this project are:1. Regulated Power Supply.

2. User Input Interfacing.

3. Voice Recording Module.

4. Tone Generating circuit 5. Micro controller.

1.2. Block diagram

The block diagram of Microcontroller enabled speaking system for deaf and dumb are as follows:-Fig 1.1: - Simple Block diagram of Microcontroller enabled speaking system for deaf and dumb.From the fig 1.1, we can understand the working of Microcontroller enabled speaking system for deaf and dumb as we can see there are five main blocks as 8051 controller, Regulated Power Supply, Buzzer, Control Buttons, Voice Driver Circuit, LED Indicator, and IC Based Voice Circuit. As we can see the microcontroller in the heart of the device and it controls each and every part of the device. The controller is programmed in C language in Keil IDE which is used to develop logics. The micro controller controls the voice drive circuit.This Voice circuit works on 5v Dc and produces a loud sound for different purposes and behaves as an alarm system.

The fig 1.1 describes the different processes of device as the micro controller controls the Voice module according to the defined input which we are providing through the switches. All these switches provide a high pulse for the input port and a predefined programming of the microcontroller generates the corresponding output signals for different LEDs and different sounds.8051 C: The 8051 microcontroller is the heart of the device as it controls each part and processes of the device. It is the 8 bit microcontroller which provides an automatic control.Voice Driver CircuitThe APR9600 device offers true single-chip voice recording, non-volatile storage, and playback capability for 40 to 60 seconds. The device supports both random and sequential access of multiple messages. Sample rates are user-selectable, allowing designers to customize their design for unique quality and storage time needs. Integrated output amplifier, microphone amplifier, and AGC circuits greatly simplify system design. The device is ideal for use in portable voice recorders, toys, and many other consumer and industrial applications.

Fig 1.2: - Voice Driver CircuitLEDs:

A Light Emitting Diode is a two lead semiconductor light source that resembles a basic PN junction diode, except that an LED also emits light.

Fig 1.3: - LEDsSwitches:

In electronics, an electronic switch is an electronic component or device that can switch an electrical circuit, interrupting the current or diverting it from one conductor to another

Fig 1.4: - Relay circuit7805 VOLTAGE REGULATOR:

7805 is a voltage regulator integrated circuit. It is a member of 78xx series of fixed linear voltage regulator IC. The voltage source in a circuit may have fluctuations and would not give the fixed voltage output.

Fig 1.5: - 7805 voltage regulator IC1.2.1 ComponentsS. noComponents

1.2.1.1P89V51RD2BN

1.2.1.2Voice driver circuit

1.2.1.3LEDs

1.2.1.4Resistances

1.2.1.5Capacitances

1.2.1.6Crystal

1.2.1.7Switches

1.2.1.87805 IC

1.2.1.9Adapter

Table: - 1.1 list of components1.2.1.1 P89V51RD2BN (8051C): The P89V51RD2 is an 80C51 microcontroller with 64 kB Flash and 1024 bytes of data RAM. A key feature of the P89V51RD2 is its X2 mode option. The design engineer can choose to run the application with the conventional 80C51 clock rate (12 clocks per machine cycle) or select the X2 mode (6 clocks per machine cycle) to achieve twice the throughput at the same clock frequency. Another way to benefit from this feature is to keep the same performance by reducing the clock frequency by half, thus dramatically reducing the EMI.The Flash program memory supports both parallel programming and in serial In-System Programming (ISP). Parallel programming mode offers gang-programming at high speed, reducing programming costs and time to market. ISP allows a device to be reprogrammed in the end product under software control. The capability to field/update the application firmware makes a wide range of applications possible. The P89V51RD2 is also In-Application Programmable (IAP), allowing the Flash program memory to be reconfigured even while the application is running.The highlighted features are: -

80C51 Central Processing Unit 5 V Operating voltage from 0 to 40 MHz 64 kB of on-chip Flash program memory with ISP (In-System Programming) and IAP (In-Application Programming) Supports 12-clock (default) or 6-clock mode selection via software or ISP SPI (Serial Peripheral Interface) and enhanced UART PCA (Programmable Counter Array) with PWM and Capture/Compare functions Four 8-bit I/O ports with three high-current Port 1 pins (16 mA each) Three 16-bit timers/counters Programmable Watchdog timer (WDT) Eight interrupt sources with four priority levels Second DPTR register Low EMI mode (ALE inhibit) TTL- and CMOS-compatible logic levelsBlock diagram of the IC is shown below to demonstrate the architecture: -

Fig 1.6: - Architecture of P89V51RD2BNTo understand the working of this IC lets have a look on PIN diagram of the IC P89V51RD2BN.

Fig 1.7:- PIN diagram of P89V51RD2BNThe pin description is given in the table below: -

SymbolPinTypeDescription

P0.0 to

P0.739-32I/OPort 0: Port 0 is an 8-bit open drain bi-directional I/O port. Port 0 pins that have 1s written to them oat, and in this state can be used as high-impedance inputs. Port 0 is also the multiplexed low-order address and data bus during accesses to external code and data memory. In this application, it uses strong internal pull-ups when transitioning to 1s. Port 0 also receives the code bytes during the external host mode programming, and outputs the code bytes during the external host mode verication. External pull-ups are required during program verication or as a general purpose I/O port.

P1.0 to

P1.7

1-8I/O port with

internal pull-upPort 1: Port 1 is an 8-bit bi-directional I/O port internal pull-up. The Port 1 pins are pulled high by the internal pull-ups when 1s are written to them and can be used as inputs in this state. As inputs, Port 1 pins that are externally pulled LOW will source current (IIL) because of the internal pull-ups. P1.5, P1.6, P1.7 have high current drive of 16 mA. Port 1 also receives the low-order address bytes during the external host mode programming and verication.

P1.01I/OT2: External count input to Timer/Counter 2 or Clock-out from Timer/Counter 2

P1.12IT2EX: Timer/Counter 2 capture/reload trigger and direction control

P1.23IECI: External clock input. This signal is the external clock input for the PCA.

P1.34I/OCEX0: Capture/compare external I/O for PCA Module 0. Each capture/compare module connects to a Port 1 pin for external I/O. When not used by the PCA, this pin can handle standard I/O.

P1.45I/OSS: Slave port select input for SPI CEX1:Capture/compare external I/O for PCA Module 1

P1.56I/OMOSI: Master Output Slave Input for SPI

CEX2: Capture/compare external I/O for PCA Module 2

P1.67I/OMISO: Master Input Slave Output for SPI

CEX3: Capture/compare external I/O for PCA Module 3

P1.78I/OSCK: Master Output Slave Input for SPI

CEX4: Capture/compare external I/O for PCA Module 4

P2.0 to

P2.721-28I/O with internal pull-upPort 2: Port 2 is an 8-bit bi-directional I/O port with internal pull-ups. Port 2 pins are pulled HIGH by the internal pull-ups when 1s are written to them and can be used as inputs in this state. As inputs, Port 2 pins that are externally pulled LOW will source current (IIL) because of the internal pull-ups. Port 2 sends the high-order address byte during fetches from external program memory and during accesses to external Data Memory that use 16-bit address (MOVX@DPTR). In this application, it uses strong internal pull-ups when transitioning to 1s. Port 2 also receives some control signals and a partial of high-order address bits during the external host mode programming and verication.

P3.0 to

P3.710-17I/O with internal

pull-upPort 3: Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. Port 3 pins are pulled HIGH by the internal pull-ups when 1s are written to them and can be used as inputs in this state. As inputs, Port 3 pins that are externally pulled LOW will source current (IIL) because of the internal pull-ups. Port 3 also receives

some control signals and a partial of high-order address bits during the external host mode programming and verication.

P3.010IRXD: serial input port

P3.111OTXD: serial output port

P3.212IINT0: external interrupt 0 input

P3.313IINT1: external interrupt 1 input

P3.414IT0: external count input to Timer/Counter 0

P3.515IT1: external count input to Timer/Counter 1

P3.616OWR: external data memory write strobe

P3.717ORD: external data memory read strobe

PSEN29Program Store Enable: PSEN is the read strobe for external program memory. When the device is executing from internal program memory, PSEN is inactive (HIGH). When the device is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory. A forced HIGH-to-LOW input transition on the PSEN pin while the RST input is continually held HIGH for more than 10 machine cycles will cause the device to enter external host mode programming.

RST9IReset: While the oscillator is running, a HIGH logic state on this pin for two machine cycles will reset the device. If the PSEN pin is driven by a HIGH-to-LOW input transition while the RST input pin is held HIGH, the device will enter the external host mode, otherwise the device will enter the normal operation mode.

EA31IExternal Access Enable: EA must be connected to VSS in order to enable the device to fetch code from the external program memory. EA must be strapped to VDD for internal program execution. However, Security lock level 4 will disable EA, and program execution is only possible from internal program memory. The EA pin can tolerate a high voltage of 12V.

ALE/

PROG30I/OAddress Latch Enable: ALE is the output signal for latching the low byte of the address during an access to external memory. This pin is also the programming pulse input (PROG) for ash programming. Normally the ALE[1] is emitted at a constant rate of 16 the crystal frequency[2] and can be used for external timing and clocking. One ALE pulse is skipped during each access to external data memory. However, if AO is set to 1, ALE is disabled.

NCI/ONo Connect

XTAL119ICrystal 1: Input to the inverting oscillator amplier and input to the internal clock generator circuits.

XTAL218OCrystal 2: Output from the inverting oscillator amplier.

VDD40IPower supply

VSS20IGround

Table 1.1: - PIN description of P89V51RD2BN1.2.1.1.0 Memory organization

The device has separate address spaces for program and data memory.

1.2.1.1.0.0 Flash program memory

There are two internal ash memory blocks in the device. Block 0 has 64 k bytes and contains the users code. Block 1 contains the Philips-provided ISP/IAP routines and may be enabled such that it overlays the rst 8 k bytes of the user code memory.

The 64 kB Block 0 is organized as 512 sectors, each sector consists of 128 bytes.

Access to the IAP routines may be enabled by clearing the BSEL bit in the FCF register. However, caution must be taken when dynamically changing the BSEL bit. Since this will cause different physical memory to be mapped to the logical program address space, the user must avoid clearing the BSEL bit when executing user code within the address range 0000H to 1FFFH.

1.2.1.1.0.1 Data RAM memory

The data RAM has 1024 bytes of internal memory. The device can also address up to 64 kB for external data memory.

1.2.1.1.0.2 Expanded data RAM addressing

The P89V51RD2 has 1 kB of RAM. See Figure 5 Internal and external data memory structure. on page 17.

The device has four sections of internal data memory:

1. The lower 128 bytes of RAM (00H to 7FH) are directly and indirectly addressable.

2. The higher 128 bytes of RAM (80H to FFH) are indirectly addressable.

3. The special function registers (80H to FFH) are directly addressable only.

4. The expanded RAM of 768 bytes (00H to 2FFH) is indirectly addressable by the move external instruction (MOVX) and clearing the EXTRAM bit. (See Auxiliary Register (AUXR) in Section 6 Special function registers on page 10)

Since the upper 128 bytes occupy the same addresses as the SFRs, the RAM must be accessed indirectly. The RAM and SFRs space are physically separate even though they have the same addresses.

Voice ModuleThe APR9600 device offers true single-chip voice recording, non-volatile storage, and playback capability for 40 to 60 seconds. The device supports both random and sequential access of multiple messages. Sample rates are user-selectable, allowing designers to customize their design for unique quality and storage time needs. Integrated output amplifier, microphone amplifier, and AGC circuits greatly simplify system design. The device is ideal for use in portable voice recorders, toys, and many other consumer and industrial applications.

APLUS integrated achieves these high levels of storage capability by using its proprietary analog/multilevel storage technology implemented in an advanced Flash non-volatile memory process, where each memory cell can store 256 voltage levels.

This technology enables the APR9600 device to reproduce voice signals in their natural form. It eliminates the need for encoding and compression, which often introduce distortion.

Fig 1.8 :- PIN diagram of voice modular IC

FEATURES

Single-chip, high-quality voice recording & playback solution.

- No external ICs required. - Minimum external components.

Non-volatile Flash memory technology. -No battery backup required.

User-Selectable messaging options.

- Random access of multiple fixed-duration messages. - Sequential access of multiple variable-duration messages.

User-friendly, easy-to-use operation.

- Programming & development systems not required.

- Level-activated recording & edge-activated play back switches.

Low power consumption.

- Operating current: 25 mA typical.

- Standby current: 1 uA typical. - Automatic power-down.

Literature Review

2.1 Microcontroller DevicesA microcontroller can be considered a self-contained system with a processor, memory and peripherals and can be used as an embedded system.[6] The majority of microcontrollers in use today are embedded in other machinery, such as automobiles, telephones, appliances, and peripherals for computer systems. While some embedded systems are very sophisticated, many have minimal requirements for memory and program length, with no operating system, and low software complexity. Typical input and output devices include switches, relays, solenoids, LEDs, small or custom LCD displays, radio frequency devices, and sensors for data such as temperature, humidity, light level etc. Embedded systems usually have no keyboard, screen, disks, printers, or other recognizable I/O devices of a personal computer, and may lack human interaction devices of any kind.

Interrupts

Microcontrollers must provide real time (predictable, though not necessarily fast) response to events in the embedded system they are controlling. When certain events occur, an interrupt system can signal the processor to suspend processing the current instruction sequence and to begin an interrupt service routine (ISR, or "interrupt handler"). The ISR will perform any processing required based on the source of the interrupt, before returning to the original instruction sequence. Possible interrupt sources are device dependent, and often include events such as an internal timer overflow, completing an analog to digital conversion, a logic level change on an input such as from a button being pressed, and data received on a communication link. Where power consumption is important as in battery operated devices, interrupts may also wake a microcontroller from a low power sleep state where the processor is halted until required to do something by a peripheral event.

Programs

Typically microcontroller programs must fit in the available on-chip program memory, since it would be costly to provide a system with external, expandable, memory. Compilers and assemblers are used to convert high-level language and assembler language codes into a compact machine code for storage in the microcontroller's memory. Depending on the device, the program memory may be permanent, read-only memory that can only be programmed at the factory or program memory that may be field-alterable flash or erasable read-only memory.

Manufacturers have often produced special versions of their microcontrollers in order to help the hardware and software development of the target system. Originally these included EPROM versions that have a "window" on the top of the device through which program memory can be erased by ultraviolet light, ready for reprogramming after a programming ("burn") and test cycle. Since 1998, EPROM versions are rare and have been replaced by EEPROM and flash, which are easier to use (can be erased electronically) and cheaper to manufacture.

Other versions may be available where the ROM is accessed as an external device rather than as internal memory, however these are becoming increasingly rare due to the widespread availability of cheap microcontroller programmers.

The use of field-programmable devices on a microcontroller may allow field update of the firmware or permit late factory revisions to products that have been assembled but not yet shipped. Programmable memory also reduces the lead time required for deployment of a new product.

Where hundreds of thousands of identical devices are required, using parts programmed at the time of manufacture can be an economical option. These "mask programmed" parts have the program laid down in the same way as the logic of the chip, at the same time.

A customizable microcontroller incorporates a block of digital logic that can be personalized in order to provide additional processing capability, peripherals and interfaces that are adapted to the requirements of the application. For example, the AT91CAP from Atmel has a block of logic that can be customized during manufacture according to user requirements.Microcontrollers usually contain from several to dozens of general purpose input/output pins (GPIO). GPIO pins are software configurable to either an input or an output state. When GPIO pins are configured to an input state, they are often used to read sensors or external signals. Configured to the output state, GPIO pins can drive external devices such as LEDs or motors.

Many embedded systems need to read sensors that produce analog signals. This is the purpose of the analog-to-digital converter (ADC). Since processors are built to interpret and process digital data, i.e. 1s and 0s, they are not able to do anything with the analog signals that may be sent to it by a device. So the analog to digital converter is used to convert the incoming data into a form that the processor can recognize. A less common feature on some microcontrollers is a digital-to-analog converter (DAC) that allows the processor to output analog signals or voltage levels.

In addition to the converters, many embedded microprocessors include a variety of timers as well. One of the most common types of timers is the Programmable Interval Timer (PIT). A PIT may either count down from some value to zero, or up to the capacity of the count register, overflowing to zero. Once it reaches zero, it sends an interrupt to the processor indicating that it has finished counting. This is useful for devices such as thermostats, which periodically test the temperature around them to see if they need to turn the air conditioner on, the heater on, etc.

A dedicated Pulse Width Modulation (PWM) block makes it possible for the CPU to control power converters, resistive loads, motors, etc., without using lots of CPU resources in tight timer loops.

Universal Asynchronous Receiver/Transmitter (UART) block makes it possible to receive and transmit data over a serial line with very little load on the CPU. Dedicated on-chip hardware also often includes capabilities to communicate with other devices (chips) in digital formats such as IC and Serial Peripheral Interface (SPI).3 Methodology3.1 There are five steps in PCB designing

1. Circuit & layout designing

2. Ironing

3. Etching

4. Drilling

5. Soldering

Circuit & Layout Designing

We have used Cadstar software for circuit design. We have used Orcade for layout designing. The PCB layout is a mirrored positive one black on white. After the layout designing we print the layout in butter paper or glossy paper. Now we have the layout. Now other process has to come.

Fig 1.9 :- Layout design of speaking microcontroller

Ironing process

Ironing is the process in which we take the print of layout from glossy paper to PCB.Fig 1.10:- Ironing process

Etching process

The developed PCB is etching with a 220 g/l solution of FeCl3 (Ferrous Chloride).220 gram added to one litter of water and mix it until everything is dissolved.When the Ferrous Chloride is dissolved it is a clear liquid.After the etching process total part of copper will be remove.Fig 1.11 :-Etching process

Drilling process

Drilling is the process in which we drill the holes on PCB for the placement of component.

Fig 1.12 :-Drilling processSoldering process In this process we placed the component in there right place in PCB. We use soldering wire to place the component tightly.Fig 1.13 :- Soldering processCODING//Program to interface voice module with 8051 microcontroller (AT89S52)

#include

sbit ip1=P1^0;//input for switch1

sbit ip2=P1^1;//input for switch2

sbit ip3=P1^2;// input for switch3

sbit ip4=P1^3;//input for switch4

sbit v1=P2^0;// output for 1st voice

sbit v2=P2^1; // output for 2nd voice

sbit v3=P2^2; // output for 3rd voice

sbit v4=P2^3; // output for 4th voice

sbit bzr=P2^7;// output for buzzer

void delay(unsigned int count) //Function to provide delay

{

int i,j;

for(i=0;i