Download - Solar Based Assistive Technology for Voice Impaired

Project Report on

Solar Based Assistive Technology for Voice

Impaired

Submitted in partial fulfillment of the requirements

of the degree of

BACHELOR OF ENGINEERING

in

ELECTRONICS AND TELECOMMUNICATION

by

Aayush Misra (Roll No. 62)

Rishabh Dubey (Roll No.70)

Mitch Fernandes (Roll No. 71)

Under the guidance of

Ms. Lakshmi G. Prabhu

Department of Electronics and Telecommunication Engineering

St. Francis Institute of Technology, Mumbai

University of Mumbai

(2017-2018)

ii

iii

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ABSTRACT

Voice impaired people have difficulty in communicating with normal people because

hand gestures used by them to communicate their information is not easily understandable;

only trained people can understand these. Most expressions and emotions remains un-

conveyed sometimes even misinterpreted. So hand gestures are not an effective method for the

speech impaired people. To take care of this issue, an assistive technology can be used to

enhance communication. This is done by using ATmega328 microcontroller. The assistive

technology consist of specialized keypad in which each key corresponds to a pre-

assigned recorded audio that can be played to convey the message by the voice impaired

person.

Keywords: Voice Impairment, Assistive Technology, Solar Power.

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Contents

Chapter 1 Introduction 01

1.1 Motivation 01

1.2 Problem Statement 02

1.3 Methodology 02

1.4 Organization of Project Report 02

Chapter 2 Literature Review 04

2.1 Electronic Speaking Glove for Speechless Patients 04

2.2 Development of an Assistive Aid for Speech Impaired 04

2.3 Speaking Gloves for Speechless Person 05

2.4 Extraction of Vocal-Tract System Characteristics from Speech 05

Signals

Chapter 3 Design Methodology 06

3.1 Working 06

3.1.1 Transmitter 06

3.1.2 Receiver 07

3.2 Circuit Diagram 08


3.2.2 Receiver 09

3.2 Component List and Description 10

3.2.1 ATmega328 12

3.2.2 aPR33A3 Voice IC 16

3.2.3 HT12E Encoder 17

3.2.4 HT12D Decoder 18

3.2.5 IC7805 19

3.2.6 RF Module (Transmitter And Receiver) 20

3.2.7 Solar Panel 21

3.3 Software Support Overview 23

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3.3.1 Proteus 23

3.3.2 Arduino IDE 23

3.4 Program Code 24


3.4.2 Receiver 30

Chapter 4 Simulation and Experimental Results 32

4.1 Simulation on PCB 32


4.1.2 Receiver 33

Chapter 5 Conclusion 34

5.1 Conclusion 34

5.2 Future Scope 34

Appendix Timeline 35

References 37

Acknowledgement 38

vii

List of Figures

Figure

No.

Figure Captions Page

No.

3.1 Transmitter Block Diagram 06

3.2 Receiver Block Diagram 07

3.3 Transmitter Circuit Diagram 08

3.4 Receiver Block Diagram 09

3.5 Block diagram of Atmega328 14

3.6 Pin diagram of Atmega328 15

3.7 Pin diagram of aPR33A3 Voice IC 16

3.8 Pin diagram of HT12E 17

3.9 Pin diagram of HT12D 18

3.10 Pin diagram of LM7805 19

3.11 Pin diagram of RF Module for Transmitter and Receiver 20

3.12 Solar Cell Structure 21

3.13 Solar Panel Used for the Project 22

4.1 Simulation Result for Transmitter 32

4.2 Simulation Result for Receiver 33

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List of Tables

Table

No.

Title Page

No.

3.1 Component List and Description 10

Timeline Chart 35

9

List of Abbreviations

AAC Alternative and Augmentative Communication

IC Integrated Circuit

LED Light Emitting Diode

AVR Alf and Vegard’s RISC processor

RISC Reduced Instruction Set Computer

EPROM Electrically Programmable Read Only memory

SRAM Static Random Access Memory

USART Universal Synchronous/Asynchronous Receiver ...

SPI Serial Peripheral Interface

JTAG Joint Test Action Group

RF Radio Frequency

PCB Printed Circuit Board

IDE Integrated Development Environment

http://r.search.yahoo.com/_ylt=AwrwXx1fZAFalRcA5l7nHgx.;_ylu=X3oDMTBycWJpM21vBGNvbG8Dc2czBHBvcwMxBHZ0aWQDBHNlYwNzcg--/RV=2/RE=1510069471/RO=10/RU=http%3a%2f%2fwhatis.techtarget.com%2fdefinition%2fUSART-Universal-Synchronous-Asynchronous-Receiver-Transmitter/RK=1/RS=99B4KIVw5h9Pv33hVrEXaWCG_wM-

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Chapter 1

Introduction

“More important than the right to speech is the right to speak.” The world renowned British

theoretical physicist Stephen Hawking knows this exactly to be true. Having been robbed of

his ability to speak to a motor neuron disease, Stephen Hawking had to struggle with crude

communication systems just to be able to tell his wants and needs. How frequently do

we meet a voice impaired person in normal life? How visible are they in offices? The truth is

that there is often little room for these people in the workplaces. Voice impairment is

a communication problem in which the normal speech is disrupted due to

articulation problems.

1.1 Motivation

People with complex communication needs often struggle with verbal language and require an

Alternative and Augmentative Communication (AAC) strategy. Suffering from voice

impairment can have negative social effects, especially among young children.

Generally voice impaired people communicate in sign languages which is not understood by

majority of people so they are not an effective method of communication. To take care of this

issue, an assistive device can be used to enhance the passage of communication. The assistive

device would consist of a specialized keypad in which each key would correspond to a pre-

assigned recorded audio that can be played to convey the message by

the voice-impaired person. The keypad matrix that would consist of a pre-assigned recorded

audio would be an element of the transmitter, so whenever the person wants to communicate a

specific word or a speech, he would press the specific input on the keypad matrix

with respect to that particular speech. The output for that particular speech would be heard on

the receiver section via a speaker.

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1.2 Problem Statement

Voice impaired people have difficulty in communicating with normal people because hand

gestures used by them to communicate their information is not easily understandable, only

trained people can understand these. Most expressions and emotions remains un-

conveyed sometimes even misinterpreted. So hand gestures are not an effective method for

the speech impaired people. To take care of this issue, an assistive technology can be used to

enhance the communication.

1.3 Methodology

We intend to design an assistive technology consisting of transmitter and receiver sections.

This assistive device could be useful for voice impaired and partially paralyzed people

to remove the communication barrier between them and the society. The main reason

to use solar as a power source is that it does not cause pollution and carbon emissions and it

has potential to harness infinitely.

1.4Organization of Project Report

This project report is organized as follows:

(i) Chapter 2: This chapter comprises of the literature survey of the project and contains

a list of various papers read along with the abstract regarding the proposed system discussed

in the respective papers.

(ii) Chapter 3: This chapter comprises of the methodology of the device which consists of

the block diagram and circuit diagrams of the transmitter and receiver sections component list

and a description of the important integrated circuits required for the project, the

software support required and the program code implemented for the project.

(iii) Chapter 4: This chapter comprises of the simulation results obtained during the

implementation of the project.

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(iv) Chapter 5: This chapter comprises of the conclusion drawn from the

project implementation and the future scope of the project in which we describe about

further modifications possible for the device.

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Chapter 2

Literature Survey

In this section, we give a description about the various papers that we had read for

the research of our project. The list of the references read along with the authors of the papers

is given in the following

2.1 Electronic Speaking Glove for Speechless Patients, A Tongue to a

Dumb by Syed Faiz Ahmez [1]

Generally, a speechless person communicates through sign language which is not understood

by the majority of people. This project is designed to solve this problem. Finger gestures of a

user will be converted into synthesized speech to convey an audible message to others, for

example in a critical communication with doctors. A glove is used for this purpose. The glove

is internally equipped with multiple flex sensors that are made up of "bend-sensitive

resistance elements".

2.2 Development of an Assistive Aid for Speech Impaired by Aparna

P, Mohana Priya P, Usha Rani T, Jeba Jaculin B, Pradeep Raja B [2]

This system is implemented in real time to express the basic needs of speech impaired. The

proposed system is a user dependent system in which the speech IC is trained by the

individual who will be using the system. It employs an acoustic plate to sense the

vocal vibration. These vibrations are amplified and processed by the speech IC. The speech IC

is trained with certain words. When the trained words are spoken by the user, the

vibrations produced are recognized and compared by the speech IC. The PIC controller

is interfaced with recording and playback IC. The recording and playback IC is capable of

recording up to

8 messages. The PIC controller is programmed in such a way it directs the output of

the speech IC to the corresponding pins of the playback IC and audio output is

produced by means of speaker.

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2.3 Speaking Gloves for Speechless Person by Abjhijt Auti, V. G. Puranik,

Dr. A. K. Kureshi [3]

A speechless person communicates through sign language which is not understood by the any

people. The proposed system in this paper is designed to solve the problem. In this system

they have used IVR341N which is a 8-bit MCU based Voice chip. It can store 341sec voice

message with 4-bit ADPCM compression at 6KHz sampling rate and it requires an external

memory for voice storing.

2.4 Extraction of Vocal-Tract System Characteristics from Speech Signals

by B. Yegnanarayana and Raymond N. J. Veldhuis [4]

This paper concentrates in the cases where vocal characteristics vary over time, as happens in

dynamic sounds such as consonant-vowel transitions. These instants are obtained by a

method based on the average group-delay property of minimum-phase signals. In

voiced speech, they correspond to the instants of glottal closure. The vocal-tract

system is characterized by its formant parameters, which are extracted from the analysis

segments.

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Chapter 3

3.1 Working

3.1.1 Transmitter

Design Methodology

Fig 3.1 Transmitter Block Diagram

There are two separate microcontrollers for transmitter and receiver. In the transmitter section,

the keypad matrix is connected to digital input/output pins of micro-controller, which is used as

the input device. The microcontroller on board scans the key being pressed and sends a 4-bit

code representing the key pressed to I/O of board.

These four bits are transferred to HT12E encoder for conversion of parallel data into serial data,

which is fed into the RF transmitter. It then transmits the serial data at 433MHz using ASK

modulation. The 750kΩ resistor determines the oscillator frequency of the transmitter side.

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3.1.2 Receiver

Fig 3.2 Receiver Block Diagram

In the receiver section, the 4-bit code is received using the RF receiver and data bits

are decoded if and only if the extracted address from the transmitted code matches the

pre- programmed address in HT12D decoder address pins. If the decoded address and

pre- programmed address matches, the LED corresponding to HT12D (at pin 17) glows. The 33

kΩ resistor determines the oscillator frequency of the receiver.

The decoded output from HT12D is then sent to the microcontroller to generate a binary code

corresponding to it. This output is further from the microcontroller is further sent to 74HCT154

decoder to further trigger aPR33A3 voice IC. In response to the trigger from the decoder, the

voice IC generates corresponding audio messages programmed earlier.

74HCT154, a 4-to-16 line decoder is used to drive the select pins of the voice IC as the number

of input/output pins on the microcontroller is insufficient to drive the voice IC.

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3.2 Circuit Diagram

3.2.1 Transmitter

Fig 3.3 Transmitter Circuit Diagram

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3.2.2 Receiver

Fig 3.4 Receiver Circuit Diagram

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3.3 Component List and Description

Specification Component Name

(a) Semiconductors

IC1, IC3 7805 voltage regulator

IC2 HT12E encoder

IC4 HT12D decoder

IC5 74HCT154, 4-to-16 line decoder

IC6 APR33A3 voice record and play back IC

IC7 LM386 low-voltage audio power amplifier

LED1 5mm LED

TX1 433MHz RF transmitter module

RX1 433MHz RF receiver module

BOARD1, BOARD2 Arduino UNO board

(b) Resistors

R1 750-kilo-ohm

R2-R7, R12, R13 1-kilo-ohm

R8 33-kilo-ohm

R9 47-kilo-ohm

R10, R11, R14 4.7-kilo-ohm

(c) Capacitors

C1, C2, C9 1uF, 16V electrolytic

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C3 10uF,16V electrolytic

C4, C5, C10 100uF,16V electrolytic

C6, C7, C11 100nF ceramic

C8, C12 1nF ceramic

(d) Miscellaneous

CON1, CON3 2-pin connector

CON2 12-pin connector



LS1 4-ohms, 0.5W speaker

MIC1 Electret condenser microphone

ANT1, ANT2 30cm-long single-strand wire antenna

BATT1, BATT2 Solar Powered Battery

S1-S16, S18 Tactile switch

S17 On/Off toggle switch, USB A-B cable

Table 3.1

The Arduino UNO Board contains the ATmega328 microcontroller.

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3.3.1 ATmega328

The ATmega328 is a single chip micro-controller created by Atmel and belongs to the mega

AVR series. The Atmel 8-bit AVR RISC - based microcontroller combines 32 KB ISP flash

memory with read-write capabilities, 1KB EPROM, 2KB SRAM, 23 general purpose

I/0 lines, 32 general purpose registers, three flexible timer/counters with compare modes,

internal and external interrupts, serial programmable USART , a byte-oriented 2-wire serial

interface, SPI serial port, 6-channel 10-bit A/D converter (8-channels in TQFP and

QFN/MLF packages), programmable watchdog timer with internal oscillator, and

five software selectable power saving modes. The device operates between 1.8-5.5

volts. The device ATmega32 microcontroller which belongs to Atmel’s AVR series

micro controller family. ATmega32 is based on RISC (Reduced Instruction Set

Computing) architecture with 131 powerful instructions. Most of the instructions execute in

one machine cycle. ATmega32 can work on a maximum frequency of 16MHz. By

executing powerful instructions in a single clock cycle, the ATmega32 achieves

throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power

consumption versus processing speed.

Features of ATmega 328 microcontroller:

(i) PIN count: Atmega32 has got 40 pins. Two for Power (pin no.10: +5v, pin no.

11: ground), two for oscillator (pin 12, 13), one for reset (pin 9), three for providing necessary

power and reference voltage to its internal ADC, and 32 (4×8) I/O pins.

(ii) About I/O pins: ATmega32 is capable of handling analogue inputs. Port A can be used as

either DIGITAL I/O Lines or each individual pin can be used as a single input channel to the

internal ADC of ATmega32, plus a pair of pins AREF, AVCC & GND together can make an

ADC channel.

No pins can perform and serve for two purposes (for an example: Port A pins cannot work as

a Digital I/O pin while the Internal ADC is activated) at the same time. It’s the programmers

responsibility to resolve the conflict in the circuitry and the program. Programmers are

advised to have a look to the priority tables and the internal configuration from the datasheet.

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(iii) Digital I/O pins: ATmega32 has 32 pins (4portsx8pins) configurable as Digital I/O pins.

(iv) Timers: 3 Inbuilt timer/counters, two 8 bit (timer0, timer2) and one 16 bit (timer1).

(v) ADC: It has one successive approximation type ADC in which total 8 single

channels are selectable. They can also be used as 7 (for TQFP packages) or 2 (for

DIP packages) differential channels. Reference is selectable, either an external reference can

be used or the internal 2.56V reference can be brought into action. There external

reference can be connected to the AREF pin.

(vi) Analog Comparator: On-chip analog is available. An interrupt is assigned for different

comparison result obtained from the inputs.

(vii) External Interrupt: 3 External interrupts are accepted. Interrupt sense is configurable.

(viii) Programming: ATmega32 can be programmed either by In-System Programming via

Serial Peripheral Interface or by Parallel programming. Programming via JTAG interface is

also possible. Programmer must ensure that SPI programming and JTAG are not

diasbled using fuse bits; if the programming is supposed to be done using SPI or JTAG.

Fig 3.5 Block Diagram of ATmega328 Microcontroller

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Fig 3.6 Pin Diagram of ATmega328 Microcontroller

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3.3.2 aPR33A3 Voice IC

The aPR33A3 is a powerful audio processor along with high performance audio analog-to-

digital converters (ADCs) and digital-to-analog converters (DACs). It is a fully

integrated solution offering high performance and unparalleled integration with analog

input, digital processing and analog output functionality. The aPR33A3 incorporates all the

functionality required to perform demanding audio/voice applications.

High quality audio/voice systems with lower bill-of-material costs can be implemented with

the aPR33A3 because of its integrated analog data converters and full suite of quality-

enhancing features such as sample-rate convertor. The aPR33A3 Q7.0 is specially designed

for simple key trigger, user can record and playback the messages in random seven sections

by switch. It is suitable in simple interface, e.g. toys, leave messages system,

answering machine etc. Meanwhile, this mode provides the power-management system.

Users can let the chip enter power-down mode when unused. It can effectively reduce

electric current consuming to 15uA and increase the using time in any projects powered by

batteries.

Fig 3.7 Pin Diagram of aPR33A3 Voice IC

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3.3.3 HT12E Encoder

HT12E is an encoder integrated circuit of 212 series of encoders. They are paired with

212 series of decoders for use in remote control system applications. It is mainly used

in interfacing RF and infrared circuits. The chosen pair of encoder/decoder should have same

number of addresses and data format. Simply put, HT12E converts the parallel inputs

into serial output. It encodes the 12 bit parallel data into serial for transmission through

an RF transmitter. These 12 bits are divided into 8 address bits and 4 data bits.

HT12E has a transmission enable pin which is active low. When a trigger signal is received

on TE pin, the programmed addresses/data are transmitted together with the header bits

via an RF or an infrared transmission medium. HT12E begins a 4-word transmission cycle

upon receipt of a transmission enable. This cycle is repeated as long as TE is kept low. As

soon as TE returns to high, the encoder output completes its final cycle and then stops.

Fig 3.8 Pin Diagram of HT12E[5]

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3.3.4 HT12D Decoder

HT12D is a decoder integrated circuit that belongs to 212 series of decoders. This series

of decoders are mainly used for remote control system applications, like burglar alarm, car

door controller, security system etc. It is mainly provided to interface RF and

infrared circuits. They are paired with 212 series of encoders. The chosen pair of

encoder/decoder should have same number of addresses and data format. In simple terms,

HT12D converts the serial input into parallel outputs. It decodes the serial addresses and data

received by, say, an RF receiver, into parallel data and sends them to output data pins.

The serial input data is compared with the local addresses three times continuously. The

input data code is decoded when no error or unmatched codes are found. A valid

transmission in indicated by a high signal at VT pin. HT12D is capable of decoding 12 bits,

of which 8 are address bits and 4 are data bits. The data on 4 bit latch type output pins remain

unchanged until new is received.

Fig 3.9 Pin Diagram of HT12D[6]

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3.3.5 IC 7805

7805 is a voltage regulator integrated circuit. It is a member of 78xx series of fixed linear

voltage regulator ICs. The voltage source in a circuit may have fluctuations and would not

give the fixed voltage output. The voltage regulator IC maintains the output voltage at

a constant value. Capacitors of suitable values can be connected at input and output

pins

depending upon the respective voltage levels.

Fig 3.10 Pin Diagram of LM 7805

Voltage sources in a circuit may have fluctuations resulting in not giving fixed voltage

outputs. Voltage regulator IC maintains the output voltage at a constant value. 7805, a

voltage regulator integrated circuit (IC) is a member of 78xx series of fixed linear voltage

regulator ICs used to maintain such fluctuations. The xx in 78xx indicates the fixed output

voltage it provides. IC 7805 provides +5 volts regulated power supply with provisions to add

heat sink as well

The difference between the input and output voltage appears as heat. The greater the

difference between the input and output voltage, the more heat is generated. If too much heat

is generated, through high input voltage, the regulator can overheat. If the regulator does not

have a heat sink to dissipate this heat, it can be destroyed and malfunction. Hence, it

is advisable to limit the voltage to a maximum of 2-3 volts higher than the output voltage. So

the two options are to design the circuit so that the input voltage going into the regulator is

limited to 2-3 volts above the output regulated voltage or place an appropriate heatsink that

can efficiently dissipate heat.

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3.3.6 RF Module (Transmitter and Receiver)

The RF module, as the name suggests, operates at Radio Frequency. The corresponding

frequency range varies between 30 kHz & 300 GHz. In this RF system, the digital data is

represented as variations in the amplitude of carrier wave. This kind of modulation is known

as Amplitude Shift Keying (ASK).

Fig 3.11 Pin Diagram RF Module for Transmitter and Receiver

Transmission through RF is better than IR (infrared) because of many reasons. The signals

through RF can travel through larger distances making it suitable for long range applications.

While IR mostly operates in line-of-sight mode, RF signals can travel even when there is an

obstruction between transmitter and receiver. The RF transmission is more strong and reliable

than IR transmission. RF communication uses a specific frequency unlike IR signals which

are affected by other IR emitting sources.

This RF Module comprises of an RF Transmitter and an RF Receiver. The

transmitter/receiver (Tx/Rx) pair operates at a frequency of 433 MHz. An RF

transmitter receives serial data and transmits it wirelessly through RF through its antenna

connected at pin4. The transmission occurs at the rate of 1Kbps - 10Kbps.The transmitted data

is received by an RF receiver operating at the same frequency as that of the transmitter.

The RF Module is often used along with a pair of encoder/decoder. The encoder is used for

encoding parallel data for transmission feed while reception is decoded by a decoder.

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3.3.6 Solar Cell

Solar cell, also called photovoltaic cell, any device that directly converts the energy of light

into electrical energy through the photovoltaic effect. The overwhelming majority of

solar cells are fabricated from silicon with increasing efficiency and lowering cost as the

materials range from amorphous (noncrystalline) to polycrystalline to crystalline (single

crystal) silicon forms. Unlike batteries or fuel cells, solar cells do not utilize chemical

reactions or require fuel to produce electric power, and, unlike electric generators, they do not

have any moving parts.

Fig 3.12 Solar Cell Structure

Solar cells can be arranged into large groupings called arrays. These arrays, composed

of many thousands of individual cells, can function as central electric power stations,

converting sunlight into electrical energy for distribution to industrial, commercial, and

residential users. Solar cells in much smaller configurations, commonly referred to as solar

cell panels or simply solar panels, have been installed by homeowners on their rooftops to

replace or augment their conventional electric supply.

Fig 3.13: Solar Panel Used for the Project

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3.4 Software Support Overview

3.4.1 Proteus

Proteus combines ease of use with powerful features to help you design, test and

layout professional PCBs like never before. With nearly 800 microcontroller variants

ready for simulation straight from the schematic, one of the most intuitive professional

PCB layout packages on the market and a world class shape based autorouter included

as standard, Proteus Design Suite delivers the complete software package for today

and tomorrow's engineers. Proteus is a a software which accepts only hex files. Once

the machine code is converted into hex code, that hex code has to be dumped into the

Microcontroller and this is done by the Proteus. Proteus is a programmer which itself

contains a Microcontroller in it other than the one which is to be programmed. Different

Microcontrollers can be loaded in the Proteus software by importing their respective

libraries. This Microcontroller has a program in it written in such a way that it accept

the hex file and dumps it in the Microcontroller which is to be programmed.

3.4.2 Arduino IDE

The open-source Arduino Software IDE (short for Integrated Development

Environment) makes it easy to write code and upload it to the board. It runs on Windows,

Mac OS X, and Linux. The environment is written in Java and based on Processing and

other open-source software. The Arduino IDE is a cross-platform application which originated

from the IDE for the languages Processing and Wiring. It includes a code editor with

features such as text cutting and pasting, searching and replacing text, automatic

indenting, brace-matching and syntax highlighting, and provides simple one-click

mechanisms to compile and upload programs to an Arduino board. It also contains a

message area, a text console, a toolbar with buttons for common functions and a hierarchy of

operation menus.

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3.5 Program Code

3.5.1 Transmitter:

The source code of the transmitter side contains a 2D array for the pressed key. Initially, the

code configures the column pins and row pins for the keypad and then in the setup

{} function, it configures the output pins for Arduino. The loop function is used to output the

data bits corresponding to read character.

Source Code:

#include <Keypad.h>

char hexaKeys[4][4] = { //keypad map

{'1','2','3','A'},

{'4','5','6','B'},

{'7','8','9','C'},

{'*','0','#','D'}

};

byte rowPins[4] = {0,1,2,3}; //pins 0,1,2,3 connected row pins of keypad

byte colPins[4] = {4,5,6,7}; //pins 4,5,6,7 connected column pins of keypad

byte out[4]={10,11,12,13}; //pins 10,11,12,13 to send the four bit code to the encoder

Keypad customKeypad = Keypad( makeKeymap(hexaKeys), rowPins,

colPins,4,4);

//Configure the keypad

void setup(){

for(int i=0;i<4;i++)

{

pinMode(out[i],OUTPUT); //pins 10,11,12,13 as output

}

pinMode(A0,OUTPUT); //A0(to transmit enable pin) as output

digitalWrite(A0,1); //set transmit enable pin high

}

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void loop(){

char kp = customKeypad.waitForKey(); //read the keypad

if(kp)

{

switch(kp)

{

case '0':

digitalWrite(out[0],0); //outputing the data bits cooresponding to the read character

digitalWrite(out[1],0);



digitalWrite(A0,0); //set transmit enable pin low

delay(200);

digitalWrite(A0,1); //set transmit enable pin low

break;

case '1':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case '2':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case '3':

digitalWrite(A0,1);

36





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case '4':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case '5':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case '6':





digitalWrite(A0,0);

delay(150);



digitalWrite(A0,0);

37

break; case '7':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case '8':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case '9':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case 'A':






38

delay(150);

digitalWrite(A0,1);

break;

case 'B':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case 'C':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case 'D':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case '*':

int buff[4];

void setup()

//temporary variable

39


digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

case '#':





digitalWrite(A0,0);

delay(150);

digitalWrite(A0,1);

break;

}

kp='j';

}

}

3.5.2 Receiver:

In the receiver secion code, the I/O pins are configured for Arduino. The loop function {} is

used to read the receiving bits and convert these from binary to decimal values and send the

received data to the output pins.

Source Code:

byte ip[4] = {8,9,10,11}; //List of input pins from the HT12D

byte op[4]={3,4,5,6}; //List of output pins to the 74HCT154 decoder

int i; //loop variable

boolean b[4],rf; //variable for storing the received 4 bit code and RF reception flag

int key; //To store the integer value of received code

40

{

Serial.begin(9600); //configure serial port

for(i=0;i<4;i++) //set pins 8,9,10,11 as input

pinMode(ip[i],INPUT);

pinMode(12,INPUT); //Reception acknowledgement pin(12) as input

for(i=0;i<4;i++){

pinMode(op[i],OUTPUT); //set pins 3,4,5,6 as output

buff[i]=0;

pinMode(2,OUTPUT); //Enable pin(2) to the decoder(74HCT154) as output

digitalWrite(2,1);

}

}

void loop()

{

rf=digitalRead(12); //Read the reception acknowledgement pin

if(rf)

{

delay(200);

b[0]=digitalRead(ip[0]); // reading the received bits

b[1]=digitalRead(ip[1]);



key=(b[3]&1)+((b[2]&1)*2)+((b[1]&1)*4)+((b[0]&1)*8); //binary to decimal calculation

delay(100);

Serial.println(key); //displaying the key number(0-15) in serial

for(i=0;i<4;i++)

{

digitalWrite(op[i],b[i]); //To sent the read data to the ouput pins

}

digitalWrite(2,0); //Enable decoder(74HCT154)

delay(100);

digitalWrite(2,1); //Disable decoder(74HCT154)

}

41

Chapter 4

Simulation and Experimental Results

4.1 Simulation on PCB

4.1.1 Transmitter

Fig 4.1 Simulation Result for Transmitter

42

4.1.2 Receiver

Fig 4.2 Simulation Result for Receiver

43

Chapter 5

Conclusion

5.1 Conclusion

The source code for the transmitter section was implemented such a way that as many

as sixteen voice inputs could be stored, while the hardware was succesfully implemented

using only eight voice inputs. The blinking of the LED in the transmitter section represented

that data could be successfully transmitted to the receiver if there is any voice data stored in the

voice IC. The receiver support of the device plays an important role in this device as it

mainly consists of voice IC that is important to record and edit the speech. The blinking of the

LED in the receiver section represented that the decoded address and the pre-prograamed

address in the receiver matched successfully.

5.2 Future Scope

The project proposes an assistive device with help of solar energy to decrease the

communication barrier for the voice impaired people so that they can express their views in

front of the society. The assistive device is easy to use and is helpful to not only

voice impaired people but also those who suffer from partial paralysis. Further

implementation can be done for more number of word storage in the device. The assistive

device can also be used for home applications such as leaving a reminder, etc. Moreover,

it can also be useful for improving the speech and language of young children and hence

could further be used in various schools, etc.

44

Appendix

Timeline Chart of the Project

TIMELINE CHART FOR SEMESTER VII

MONTH JULY AUGUST SEPTEMBER OCTOBER

WEEK NO. W1 W2 W3 W4 W1 W2 W3 W4 W5 W1 W2 W3 W4 W1 W2 W3 W4

WORK TASKS

1.Problem

Definition

Search for topics

Identify the goal of

the project

2.Preparation

Study of related

IEEE papers and

books

Study of Proteus

professional

Software

Study of Arduino

IDE software

3.Implementation of

Transmitter part on

proteus

professional.

4.Implementation

of Transmitter

section

45

TIMELINE CHART FOR SEMESTER VIII

MONTH JANUARY FEBRUARY MARCH APRIL

WEEK NO. W1 W2 W3 W4 W1 W2 W3 W4 W1 W2 W3 W4 W1 W2 W3 W4

WORK TASKS

1. Execution of

Transmitter Section

in Breadboard

2. Implementation

of Receiver in

Arduino IDE

3. Execution of

Receiver Section in

Breadboard

4. Execution for

Circuits in PCB

5. Work on

Blackbook

46

References

[1] B. Ali, S. Munawwar, B. Nadeem, "Electronic Speaking Glove for Speechless Patients",

IEEE ,August 2010.

[2] T.H. Falk, J. Chan, P. Duez, G. Teachman, and T. Chau, “.Development of an Assistive

Aid for Speech Impaired,” IEEE transactions on neural systems and

rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology

Society, vol.

18, pp. 159- 63, Apr. 2010.

[3] “Speaking Gloves for Speechless Person” by Abjhijt Auti, V. G. Puranik, Dr. A. K.

Kureshi, IARJSET, Vol. 4, Special Issue 3, January 2017

[4] K.Rajeswari,E.Jeevitha, M.Meenakshi, “Extraction of Vocal-Tract System Characteristics

from Speech Signals”, IEEE, August 2011.

[5] HT12E2^12 Series of Encoders Datasheet April 11,2000

[6] HT12D2^12 Series of Decoders Datasheet April 11,2000

[7] 2017 Communication Matters,VOCAs

47