UNIVERSITI TEKNOLOGI MALAYSIA
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1. 3 2 2 1 Calibration The sensitivity of the triggering circuits needs to be calibrated in order for them to be able to easily detect signals that they need to For example if the triggering circuit using microphone is assigned to detect door knocks the sensitivity of the circuit needs to be adjusted so that it will be easy to be triggered by door knocks but not too sensitive so that the circuit won t be triggered by other sound made at the door s surrounding 24 The same thing also applied to the triggering circuit using 3 5mm male audio jack The sensitivity of this circuit also needs to be calibrated so that only a specific sound at a specific volume will be detected to trigger the circuit The calibration for both of these triggering circuits can be made by changing the value of resistor that is used for biasing one of the amplifying transistors in the circuits The bigger the value of the resistor is the less sensitive it gets 3 2 2 2 Troubleshoot In the troubleshoot process the circuits will be tested whether they are functioning as intended or not The troubleshoot process begins by testing the triggering circuit whether the input signal is able to trigger the circuit or not Troubleshoot will commence if the input signal does not triggered the circuit The next step of this process is to check whether the RF signal transmitted by the triggering circuit is received by the RF receiver at the receiving device or no2. can be overcome with the help of electronic devices 2 1 Current Reliable Product to Help Deaf People 2 1 1 Hearing Aid A hearing aid is a small electronic device that has three basic parts the microphone amplifier and speaker The hearing aid basically helps a deaf people by making sounds louder for the deaf person 2 1 1 1 The Application of Hearing Aid The three basic parts of hearing aid has their own important role in order to help the deaf person Hearing loss is caused by the lack of functioning small sensory cells in the inner ear called hair cells The more hair cells damaged in the inner ear the more severe the hearing loss is Hearing aids are worn inside or behind the ear depend on the style of the hearing aid The first basic part of the hearing aid which is the microphone is also the first process of how the hearing aid functions The microphone acts as a sensor of the deaf person s surrounding It detects surrounding sound and noises and sends it to the second basic part of the hearing aid the amplifier The amplifier functions like its name suggested amplifying the sound and noises picked up by the microphone The more hair cells in the inner ear are damaged the more the amplifier needs to amplify the sound and noises for that person The amplified sound and noises will then sent to the hair cells using a speaker These remaining hair cells will detect the louder noise produced and send the signal
3. 28 Connection for PT2272 L4 35 Connection for PT2262 35 XV LIST OF SYMBOLS AND ABBREVIATIONS BTE Behind the ear CIC Completely in canal DC Direct Current Hz Hertz ITC In the canal ITE In the ear LED Light Emitting Diode Mic Microphone RF Radio Frequency CHAPTER 1 INTRODUCTION 1 1 Project Background 1 1 1 Deaf People The term Deaf with the capital D and deaf brings two different meaning The term Deaf with the capital D refers to the community or culture of the deaf people while the term deaf refers to the symptom itself where deaf can be define as audiologic lack of hearing 1 The membership of the deaf people community is not entirely populated by a deaf person A person with normal hearing may have the membership This may be due to they are the children of a deaf person and they learn the sign language as one of their primary language since a child A deaf person also may not have the membership of a deaf community due to them still communicating verbally 1 1 2 Deaf People s Alertness Due to the lack of hearing ability deaf people are less aware of the changes in their surrounding that they can t see such as the ringing of a door bell and phones To make up for this disadvantage that they are having this project of inventing a multiple sensed device for deaf people will take advantage of their skin and touch receptor to sense vibration that will trigger on these sounds or changes th
4. Knocking on the surface the microphone is attached b LED turns from OFF to ON when triggered by knocks 42 Volume input 5V 12V Figure 4 4 Schematic circuit used on triggering circuit with 3 5mm male audio jack Another triggering circuit that needs to be calibrated in order to have the sensitivity needed is the triggering circuit with 3 5mm male audio jack The same circuit shown in Figure 4 1 was used to create this triggering circuit 28 The voltage output of the audio jack of a device is not absolutely zero even when no sound was made There s noise output that needs to be compensate so that the triggering circuit does not triggers needlessly After a few try and error adjustments the value of R1 needed was found to be 47kQ for this triggering circuit making the circuit to look like shown in Figure 4 4 Figure 4 5 Connecting the triggering circuit with 3 5mm male audio jack to an electronic device FN Figure 4 6 LED turns from OFF to ON when triggered by electrical signal from the audio output of device 4 3 Outputs 4 3 1 LED indicators In order to know which of the triggering circuit is triggered each of the triggering circuit has its own LED indicator assigned to each of them placed on the receiver device Whenever a triggering circuit is triggered a specific LED will lit up to show the user from where the signal came from 29 Figure 4 7 LED indicators lit up according to which trig
5. a b Figure 2 3 Two types of canal style hearing aid a In the canal ITC b Completely in canal CIC The canal style is very small and fits inside the wearer s ear as shown in Figure 2 3 Two types of canal style hearing aid a In the canal ITC b Completely in canal CIC The CIC style is well hidden inside the wearer s ear due to its small size Both CIC and ITC are only suitable for person with mild to moderate severe hearing loss This is because the small size has limited its battery capacity to supply a louder volume on the speaker This style also not recommended for children due to children s ear is still in a growing stage 2 1 2 Sonic Boom Alarm Clock Model SB1000ss 2 1 2 1 Overview SB1000ss The SB1000ss is a specially designed alarm clock to help the deaf to wake up from the bed It is designed so it can be used to all levels of severe of hearing impair Like a normal alarm clock it has all the normal features to show the time and let the user to set the alarm as they please What makes it different is the SB1000ss has three significant extra features to help the deaf which are an extra loud alarm system a lamp connection port and a vibrator connection port Figure 2 1 shows the SB1000ss Figure 2 4 The Sonic Boom Alarm Clock Model SB1000ss 2 1 2 2 Setting up the SB1000ss Figure 2 5 Setting up the SB1000ss Figure 2 5 shows how the SB1000ss is set up in a bedroom The SB100ss is connected
6. to the deaf person 2 1 1 2 Styles of Hearing Aids As mentioned before hearing aids are worn inside or behind of the ear The way that hearing aids are worn differs based on its design and style There are three basic styles of hearing aids 2 1 1 2 1 Behind the ear BTE Receiver in ear canal Figure 2 1 Two types of BTE style hearing aid a Classic BTE b Mini BTE Figure 2 1 Two types of BTE style hearing aid a Classic BTE b Mini BTE shows two styles of BTE that we have today These BTE are made of hard plastic case and as the name suggested are worn behind the ear with an ear mold that fits inside the ear connected The small electronic parts of the hearing aid are encased inside a small case attached behind the ear BTE are suitable for people with mild to profound hearing loss 2 1 1 2 2 In the ear ITE e Figure 2 2 In the ear Figure 2 2 In the ear shows the ITE hearing aid style This hearing aid fits completely inside the ear of the wearer The electronic parts also encased inside a hard plastic case The ITE may also have an added feature called the telecoil Telecoil is a small magnetic coil functions to detect signal through circuits instead of the microphone of the hearing aid This is very useful to help the deaf person with telephone conversation for example The ITE are not recommended for children due to the children s ear is still in the growing stage 2 1 1 2 3 Canal
7. 3 92MHz Table 3 1 RF module specifications data 3 2 1 2 1 2 BC140 transistor Figure 3 9 The BC140 transistor Although it is a common electronic component the BC140 plays a big role in the triggering circuit This NPN silicon transistor acts as a switch that activates the triggering circuits when an input is detected 5 3 2 1 2 1 3 Encoder PT2262 The encoder PT2262 is a remote control encoder utilizing CMOS Technology 6 Its pair the decoder PT2272 is equipped on the receiving device to decode which triggering circuit is activated Some of the features of this encoder are 1 Low power consumption 2 Up to 6 data pins 3 Operates at Vcc 4 15V a 19 b Figure 3 10 a The PT2262 b The pin configuration AO 1 au 18 Vcc A1 2 17 DOUT A2 3 16 OSC2 A3 4 15 OSC1 A4 5 14 ITE A5 6 13 A11 DO A6 D5 T 12 A10 D1 A7 D4 8 11 A9 D2 Vss 9 10 A8 D3 PT2262 PT2262 IR PT2262 S18 Pin Name YO Description Pin No Code Address Pin Nos 0 5 AO AS 1 These six tri state pins are detected by PT2262 1 6 to determine the encoded waveform bit 0 bit 5 Each pin can be set to 0 1 or f floating Code Address Pin Nos 6 11 Data Pin Nos 5 0 These six tri state pins are detected by A6 DS A7 D4 PT2262 to determine the encoded wa
8. PSZ 19 16 Pind 1 07 UNIVERSITI TEKNOLOGI MALAYSIA DECLARATION OF THESIS UNDERGRADUATE PROJECT PAPER AND COPYRIGHT Author s fullname ABDUL HANNAN BIN MOHD ZAHID Date of birth OCTOBER 287 1988 Title MULTIPLE SENSED DEVICE FOR DEAF PEOPLE Academic Session 2011 2012 declare that this thesis is classified as CONFIDENTIAL Contains confidential information under the Official Secret Act 1972 RESTRICTED Contains restricted information as specified by the organisation where research was done OPEN ACCESS agree that my thesis to be published as online open access full text acknowledged that Universiti Teknologi Malaysia reserves the right as follows The thesis is the property of Universiti Teknologi Malaysia The Library of Universiti Teknologi Malaysia has the right to make copies for the purpose of research only The Library has the right to make copies of the thesis for academic exchange Certified by SIGNATURE SIGNATURE OF SUPERVISOR 881028 56 6421 EN MOHAMAD SHUKRI BIN ABDUL MANAF NEW IC NO PASSPORT NO NAME OF SUPERVISOR Date 29th JUNE 2012 Date 29th JUNE 2012 NOTES i If the thesis is CONFIDENTIAL or RESTRICTED please attach with the letter from the organisation with period and reasons for confidentiality or restriction 11 T hereby declare that I have read this thesis and in my opinion this thesis 1s sufficient in term of scope and quality for award
9. PT2262 Datasheet September 2008 2008 P T Corp Remote Control Decoder PT2272 Datasheet June 2008 2008 34 APPENDICES APPENDIX A Gant chart Activity Week Searching for title Literature Review Design planning Presentation Report writing Table A 1 FYP 1 Gant Chart Activity Week 212 3 p 6 MESA O LON MEE ales USA alee ELSA LOA EA ESA ELSA 49 Fabricate device Testing troubleshoot and adjustments Improvement Presentation Report writing Table A 2 FYP 2 Gantt Chart 35 APPENDIX B Schematic circuit diagram PT2272 L4 Figure B 1 Connection for PT2272 L4 IN4148X4 Swo 2 7KQX4 MPSH10 1817 16 15 14 13 12 11 10 D PT2262 123456789 Figure B 2 Connection for PT2262
10. VW The third feature is the ability to control the bed side lamp The bedside lamp AC outlet will be connected to the SB1000ss To use this feature user must first ensure that the switch of the lamp is in the ON position When the alarm goes off 1t will automatically give supply to the lamp and turning it on User can also manually turn on the lamp by pressing the large yellow LAMP button on the front of the SB1000ss 2 1 2 4 Using the Alarm The SB1000ss has several waking options These options will determine how the SB1000ss will react upon the alarm goes off Like all the other alarm clock the SB1000ss will require the user to set the clock and the alarm first Then the waking options can be set The options are 1 Audio alarm only 2 Flashing Light with Audio On or Off 3 Vibrator with Audio On or Off 4 Flashing light and Vibrator with Audio On or Off 11 Other than having the function of triggering the alarm using timer the SB1000ss can also trigger 1ts alarm using optional transmitters sold separately by the manufacturer These optional transmitters for example are 1 DS 700 Doorbell Signaler 2 TR 75 Telephone Signaler 3 BC 400 Baby Cry Signaler CHAPTER 3 RESEARCH METHODOLOGY This chapter discusses the concept of this project as the methodology used to design and fabricate the hardware structure and electronic circuit 3 1 Concept of this project The purpose of this project is to help deaf peop
11. achieved by redesign the circuit by removing the switches used to set the addressing of the decoder Also the usage of Printed Circuit Board to make the circuit will help improve the size of the circuit The receiving device should be as small as the conventional wrist watch we have today More functions can be added to the receiving device such as an alarm that can be set to trigger the receiving device The user can set at what time the receiving device will be triggered When the time comes the vibrator will be triggered Think of this as an alarm watch feature for deaf people 32 Another future improvement that can be made is to integrate this system to a mobile phone Nowadays programs for mobile phones can be written easily The idea is to write a program that will trigger the vibrator of the mobile phone whenever one of the triggering circuits detects any changes in the surrounding Instead of using RF in this application Bluetooth signal will be used 1 2 3 4 5 6 7 REFERENCES S Barnett Clinical and cultural issues in caring for deaf people FAMILY MEDICINE KANSAS CITY vol 31 pp 17 22 1999 S Alert Alarm Clock with Super Shaker SB1000ss online S Alert Sonic Boom Alarm Clock Model SB 1000 Instruction Manual C Technologies RF Transmitter Module User s Manual vol V1 1 p 8 November 2008 2008 M E LTD BC140 BC141 datasheet P T Corp Remote Control Encoder
12. an getaran yang seterusnya akan memberi istarat kepada pengguna bahawa ada ketukan di pintu Sebagai kesimpulan peranti ini boleh menjadi satu alternatif bagi individu yang mempunyai masalah pendengeran untuk lebih peka dengan apa apa perubahan yang berlaku di tempat tempat yang diperuntukkan dalam sesuatu kawasan CHAPTER TABLE OF CONTENTS TITLE DECLARATION DEDICATION ACKNOWLEDGEMENTS ABSTRACT ABSTRAK TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF SYMBOLS AND ABBREVIATIONS INTRODUCTION 1 1 Project Background 1 1 1 Deaf People 1 1 2 Deaf People s Alertness 1 2 Problem Statement 1 3 Project Objectives 1 4 Project Scope 1 5 Aim of This Report LITERATURE REVIEW PAGE iv Vi vii viii ix xii xiii XV WO N N N e e 2 1 Current Reliable Product to Help Deaf People 2 1 1 Hearing Aid 2 1 1 1 2012 The Application of Hearing Aid Styles of Hearing Aids 21 12 1 Behind the ear BTE 21 12 2 In the ear ITE 2 1 1 2 3 Canal 2 1 2 Sonic Boom Alarm Clock Model SB1000ss 2 1 2 1 Overview SB100ss 2 1 2 2 Setting up the SB1000ss 2 1 2 3 Feature 2 1 2 4 Using the Alarm 3 RESEARCH METHODOLOGY 3 1 Concept of this project 3 2 Flow Chart 3 2 1 Hardware development 3 2 1 1 3 2 1 2 Hardware structure 3 2 1 1 1 Triggering circuits 3 2 1 1 2 Receiver device Electronic components 3 2 1 2 1 Triggering circuits 3 2 1 2 1 1 RF transmitter 3 2 1 2 1 2 BC140 transistor 3 2 1 2 1 3 E
13. at will be detected by sensors 12 Problem Statement In this modern world we are living few ways have been invented to help deaf people to overcome their hearing weakness Even though there are already several reliable devices to help them these devices still have their own weaknesses such as the hearing aid can t solve all level of deafness and some found it uncomfortable to wear 1 3 Project Objectives There are several objectives for this project which are 1 To create a device that has multiple sensors placed around an area 2 To assist deaf people using this device to gain more awareness of their surroundings 1 4 Project Scope 1 In the designing process three parts will be focused on i The sensors 11 Transmitting the signal from the sensors to the receiving device 111 The receiving device that will alert the user upon receiving signal from the sensors 2 Will be focusing on implementing only three inputs i Temperature sensor 11 Sound sensor 3 The device will be created to work in a small area such as a room 1 5 Aim of This Report The aim of this report is to make the reader understands the purpose of this project how it will be achieved and how it will help improve everyday lives of deaf people CHAPTER 2 LITERATURE REVIEW In this chapter the review of other product that has been used to help deaf people today is covered in order to give an understanding to reader on how deafness
14. e Sensed Device for Deaf People in action Work Flow Chart Triggering circuit using microphone Triggering circuit using 3 5mm male audio jack Triggering circuit using simple push button Receiver device that will be attached to the user s body Completed receiver device The RF_TX_315MHz Type2 RF transmitter The BC140 transistor a The PT2262 b The pin configuration Condenser Microphone The RF_RX_315Mhz a PT2272 L4 b Pin configuration Small imbalance rotor DC motor Schematic circuit used on triggering circuit with xiii PAGE 10 11 12 14 14 14 15 15 16 17 18 19 19 20 22 25 4 2 4 3 4 4 4 5 4 6 4 7 4 8 B 1 B 2 xiv microphone a How the triggering circuit with microphone is 25 attached on surface b Placement of the microphone Triggering circuit with microphone in action a 26 Knocking on the surface the microphone is attached b LED turns from OFF to ON when triggered by knocks Schematic circuit used on triggering circuit with 26 3 5mm male audio jack Connecting the triggering circuit with 3 5mm male 27 audio jack to an electronic device LED turns from OFF to ON when triggered by 27 electrical signal from the audio output of device LED indicators lit up according to which 28 triggering circuit is sending signal From left triggering circuit with microphone triggering circuit with 3 5mm male audio jack and simple push button a Vibrator at OFF b Vibrator at ON
15. e user s body The receiver device is the one that will be attached to the user s body It is equipped with a small imbalanced DC motor to generate vibration in order to alert the user that is wearing it Figure 3 6 shows the receiver device in two parts These two parts will then be connected using jumper wires and four PCB stands shown in Figure 3 7 Figure 3 7 Completed receiver device 17 3 2 1 2 Electronic components This sub topic discusses the main electronic components used in this project 3 2 1 2 1 Triggering circuits 3 2 1 2 1 1 RF transmitter RF_TX_315MHz Type2 Figure 3 8 The RF_TX_315MHz Type2 RF transmitter The RF_TX_315MHz Type2 is an RF transmitter produced by Cytron Can be operated at 3V to 12V this transmitter transmits 315MHz radio frequency at less or equal 10Kbps transfer rate and 25mW transmitting power if powered using 12V supply 4 Using this RF module the triggering circuits can send the triggered signal to the receiver device wirelessly 18 No Specifications RF Transmitter Module 1 Operating Voltage 3V to 12V 2 Operating Current Max lt 40mA 12V Min lt 9mA 3V 3 Oscillator SAW Surface Acoustic Wave oscillator 4 Frequency 315MHz 433 92MHz 5 Frequency error 150kHz max 6 Modulation ASK OOK 7 Transfer Rate lt 10Kbps 8 Transmitting power 25mW 315MHz 12V 9 Antenna Length 24cm 315MHz 18cm 43
16. gering circuit is sending signal From left triggering circuit with microphone triggering circuit with 3 5mm male audio jack and simple push button 4 3 2 Vibrator The vibrator is actually the most crucial output part of this project The vibrator will be used to alert the user whenever a triggering circuit is triggered There are no specific outputs of the vibrator for each triggering circuit Hence the condition of the vibrator is only two which are Condition Output No signal received OFF Signal received ON Table 4 1 Output of the vibrator for each condition b Figure 4 8 a Vibrator at OFF b Vibrator at ON CHAPTER 5 CONCLUSION This chapter concludes the research and development of this multiple sensed device for deaf people project Some of the weakness of this project and how to improve it is also included in this chapter 5 1 Conclusion The objective of this project is to help deaf people to gain more awareness of their surroundings The scope of this project is to cover only a small area such as an apartment or a small room There are already effective devices to help a deaf person not only to gain awareness but also to help them hear like normal people does But to certain deaf people they are not very comfortable with the existing device such as the hearing aid Hence this multiple sensed device for deaf people can act as an alternative for these people After various tests and expe
17. le to be more aware of their surroundings by taking advantage of their skin and touch receptor The term multiple sensed used in the project title is realized by placing three circuits at different places in a small area These circuits will be triggered using sound signals or manually By triggering these circuits RF signal will be transmitted to an RF receiver attached to the user s body and trigger a vibration to alert the user R ALERT a Sensor triggered A RF to send signal N RF signal will be received and alert the user with vibration Figure 3 1 Multiple Sensed Device for Deaf People in action 13 A situation example can be described based on Figure 3 1 Multiple Sensed Device for Deaf People in action One of the circuit sensors is attached to the door as shown The circuit is equipped with a microphone to detect any sound made on the door Whenever sound is detected it will trigger the RF transmitter and transmit RF signal This RF signal will then picked up by a receiver attached to the user s wrist and vibrates alerting the user 3 2 Flow Chart Figure 3 2 shows the work flow chart of this project Basically a work flow chart is how the project will be done shown step by step Literature review on available relevant products Develop hardware Calibration and troubleshoot Finish Figure 3 2 Work Flow Chart The literature review on available relevant products i
18. ncoder PT2262 3 2 1 2 1 4 Condenser Microphone 3 2 1 2 2 Receiver device 3 2 1 2 2 1 RF receiver 3 2 1 2 2 2 Decoder PT2272 L4 3 2 1 2 2 3 Imbalance rotor DC motor VD VD 0 0 1 nanan un A A RA ha 12 12 13 14 14 14 16 17 17 17 18 18 20 20 20 21 23 3 2 2 Calibration and troubleshoot 3221 Calibration 3222 Troubleshoot RESULT AND DISCUSSION 4 1 Microphone sensitivity 4 2 Volume input 4 3 Outputs 4 3 1 LED indicators 4 3 2 Vibrator CONCLUSION 5 1 Conclusion 5 2 Weaknesses of project 5 3 Suggestions for future improvement REFERENCES APPENDICES APPENDIX A APPENDIX B 23 23 24 25 25 27 28 28 29 30 30 31 31 33 34 35 xi TABLES NO 3 1 3 2 3 3 3 4 4 1 A 1 A 2 LIST OF TABLES TITLE RF module specifications data PT2262 pin description Technical specifications of RF_RX_315 Pin description of decoder PT2272 L4 Output of the vibrator for each condition FYP 1 Gant Chart FYP 2 Gant Chart xii PAGE 17 18 20 21 28 34 34 FIGURES NO 2 1 22 2 3 2 4 2 5 2 6 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9 3 10 3 11 3 12 3 13 3 14 4 1 LIST OF FIGURES TITLE Two types of BTE style hearing aid a Classic BTE b Mini BTE In the ear Two types of canal style hearing aid a In the canal ITC b Completely in canal CIC The Sonic Boom Alarm Clock Model SB1000ss Setting up the SB1000ss Super Shaker Bed Vibrator SS12VW Multipl
19. of the degree of Bachelor of Engineering Electrical Control and Instrumentation Signature Name of supervisor Encik Mohamad Shukri bin Abdul Manaf Date 111 MULTIPLE SENSED DEVICE FOR DEAF PEOPLE ABDUL HANNAN BIN MOHD ZAHID A thesis submitted in fulfillment of the requirement for the award of the degree of Bachelor of Engineering Electrical Control and Instrumentation Faculty of Electrical Engineering Universiti Teknologi Malaysia JUNE2012 I declare that this thesis entitled Multiple Sensed Device for Deaf People is the result of my own research except as cite in the reference The thesis has not been accepted for any degree and is not currently submitted in candidature of any degree Signature Name ABDUL HANNAN MOHD ZAHID Date Specially dedicate to My beloved family lecturers and friends who have guided and inspired me through my journey of education Also to thank their support beliefs and motivation vi ACKNOWLEDGEMENT I would like to take this opportunity to express my greatest appreciation to my supervisor of this project En Mohamad Shukri bin Abdul Manaf I would like to thank him for his supervision guidance and support during this project Besides that I would also like to thank my parents and family for giving me their support and encouragement throughout this project Last but not least also to my friends and those that have given me their support directly or indi
20. rectly vii ABSTRACT A new method to help people with hearing problem to notify some of the changes in their surrounding by using sensors placed on certain area that will trigger a device attached to the person s body In this project we are using multiple sensors placed on certain spots in an area in order to detect any changes For example the entrance door a condenser microphone is attached to the door to detect knocks on the door These knocks will trigger the RF transmitter An RF receiver in the receiving device that is attached to the user will trigger a motor and vibrates hence alerting the user about the knocks As a conclusion the device can be an alternative for people with hearing impair to notice any changes that occur at allocated spots in an area Vili ABSTRAK Satu kaedah baru untuk membantu individu yang mempunyai masalah pendengaran untuk mendengar perubahan yang berlaku di sekeliling mereka dengan menggunakan beberapa sensor yang diletakkan di kawasan tertentu yang akan mengaktifkan satu peranti yang melekat pada badan pengguna Projek ini akan menggunakan pelbagai sensor yang diletakkan pada tempat tempat tertentu di sesuatu kawasan untuk mengesan sebarang perubahan Sebagai contoh pintu dia mana satu mikrofon akan dilekatkan pada pintu untuk mengesan ketuakan pada pintu Ketukan ini akan mengaktifkan pemancar RF Penerima RF dalam peranti penerima yang berada di badan pengguna akan mengaktifkan motor dan menghasilk
21. riments the multiple sensed device for deaf people is not only achieved its objective to help deaf person to gain more awareness of their surroundings but also comfortable to wear to most people with wristwatch Hence 1t can be an alternative to help deaf people to be more aware of their surroundings 31 5 2 Weaknesses of Project There are a few weaknesses the final product has The main weakness that anyone can see instantly is that the size of the receiving device is quite large This makes it not that comfortable to wear and is not mobile enough for the user to wear One of the main concern while designing the circuit is the amount of RF signal that will be sent by the same frequency during the exhibition Hence the big circuit design by implementing switches to set the address of the decoder and encoder to ensure that no signal from other RF transmitter will trigger the receiving device Other weakness is the power of the vibrator The motor used is actually the same motor used by mobile phone to generate vibration The weak power of the vibrator may be caused by the weak power provided by the battery source and how the circuit board the vibrator attached to has absorbed the vibration making it less powerful 53 Suggestions for Future Improvement One of the main future improvements that can be made is to design a smaller and compact circuit for the receiving device to make it more comfortable and mobile for the user This can be
22. ring No Specifications RF Receiver 1 Operating Voltage 5 0V 0 5V 2 Operating Current lt 5 5mA 5 0V 3 Operating Principle Monolithic super heterodyne receiving 4 Modulation OOK ASK 5 Frequency 315MHz 433 92MHz 6 Bandwidth 2MHz 7 Sensitivity 100dBm 8 Rate lt 9 6Kbps 315MHz 95dBm 9 Data output TTL 10 Antenna Length 24cm Table 3 3 Technical specifications of RF_RX_315 3 2 1 2 2 2 Decoder PT2272 L4 AO 1 18 VCC A1 2 17 VT A2 3 16 Josci A3 4 15 Josc2 E A4 5 14 DIN A5 6 13 DO A6 7 12 Jon A7 8 11 D2 VSS 9 10 Jos b Figure 3 13 a PT2272 L4 b Pin configuration The remote control decoder PT2272 L4 uses the same CMOS technology as the encoder PT2262 7 These two encoder and decoder will be paired with each other in order to determine which triggering circuit is sending signal to the receiver device 22 Pin Name T O Desciption Pin No AO AS Code Address Pin Nos 0 5 These six tri state pins are detected by PT2272 to determine the encoded waveform bit 0 bit 5 Each pin can be set to 0 1 or f floating A6 D5 A11 D0 I O Code Address Pin Nos 6 11 Data Pin Nos 5 0 These six pins are used as higher address input bits or data output pins depending on the version type of PT2272 used When used as address inpu
23. s already covered in CHAPTER 2 of this thesis In this chapter discussion on the next steps will be covered 14 3 2 1 Hardware development This sub topic explains the hardware structure of the triggering circuit and the receiver circuit 3 2 1 1 Hardware structure 3 2 1 1 1 Triggering circuit There are three triggering circuit that were used in this project All three are triggered differently Figure 3 3 is one of the three triggering circuits that used a microphone to detect input This circuit can be used to detect any sound made in the surrounding This is the circuit that can be used to have the same effect as the example explained earlier in sub topic 3 1 Another triggering circuit is shown in Figure 3 4 This circuit is using a 3 5mm male audio jack to detect any input This circuit can be equipped ona computer or any electronic device such as phones to detect any sound signal Unlike the others the triggering circuit shown in Figure 3 5 is manually activated using a simple push button This circuit is useful for anyone in the area wants to get attention from the deaf person This circuit can also be implemented on a house doorbell system Microphone 2 N RF Transmitte ransmitter Figure 3 5 Triggering circuit using simple push button 15 16 3 2 1 1 2 Receiver device w f DEmotor y for vibration wi 6V supply 4 RE receiver Figure 3 6 Receiver device that will be attached to th
24. t While at it the data received at the receiver also was checked whether or not it matches the data sent by the triggering circuit The final step of this process is to test the receiving device The test is successful if the vibrator and LED indicator at the receiving device can be triggered using RF signal sent by the triggering circuit or not Chapter 4 RESULT AND DISCUSSION The objective of this project is to create a device that can help the deaf people to gain more awareness of what they can t see in a small area In order to find out whether or not the objective is achieved several experiments on how the device performed was done to observe the response of the device 41 Microphone sensitivity This experiment was conducted in order to ensure the triggering circuit with microphone was calibrated to have the sensitivity needed to be triggered by simple knocks on where the circuit will be attached Based on Figure 4 1 resistor R1 was adjusted in order to calibrate the sensitivity of the circuit After few try and error adjustments the value of R1 needed was found to be 270kQ in order to get the necessary sensitivity 26 5V 412V Figure 4 1 Schematic circuit used on triggering circuit with microphone a b Figure 4 2 a How the triggering circuit with microphone is attached on surface b Placement of the microphone 27 a b Figure 4 3 Triggering circuit with microphone in action a
25. ts these pins are tri state input pins and each pin can be set to 0 1 or f floating When used as output pins these pins are driven to VCC if 1 the address decoded from the waveform that was received matches the address setting at the address input pins and 2 the corresponding data bits received is a 1 bit Otherwise they are driven to VSS DIN Data Input Pin The encoded waveform received is serially fed to PT2272 at this pin 14 OSC 1 A resistor connected between illator Pin No 1 y Osma these two pins determines the OSC 2 fundamental frequency of Oscillator Pin No 2 PT2272 15 16 VT Valid Transmission Active High Signal VT in high state signifies that PT2272 receives valid transmission waveform 17 VCC Positive Power Supply VSS Negative Power Supply Table 3 4 Pin description of decoder PT2272 L4 23 3 2 1 2 2 3 Imbalance rotor DC motor Figure 3 14 Small imbalance rotor DC motor The imbalance rotor DC motor is a common mechanism used to generate vibration in mobile phones The DC motor used is small and can be operated low voltage The motor needs to be placed as close as possible to the circuit board in order to get the most of the vibration it created when it spins 3 2 2 Calibration and troubleshoot Calibration and troubleshoot the hardware is to ensure that the hardware is working as intended
26. veform bit A8 D3 I 6 bit 11 7 8 A11 D0 When these pins are used as address pins they 10 13 can be set to 0 1 or f floating When these pins are used as data pins they can be set only to 0 or 1 Transmission Enable ITE I Active Low Signal PT2262 outputs the encoded 14 waveform to DOUT when this pin is pulled to low A resistor connected OSC1 O Oscillator Pin No 1 between these two pins 15 determines the OSC2 I Oscillator Pin No 2 fundamental frequency of 16 the PT2262 Data Output Pin The encoded waveform is serially outputted to DRUI 9 this pin When PT2262 is not transmitting i DOUT outputs low Vss voltage Vcc Positive Power Supply 18 Vss Negative Power Supply 9 Table 3 2 PT2262 pin description 20 3 2 1 2 1 4 Condenser Microphone Figure 3 11 Condenser Microphone A small microphone used to detect any surrounding sound This microphone is equipped to one of the triggering circuit 3 2 1 2 2 Receiver device 3 2 1 2 2 1 RF receiver RF RX 315Mhz Figure 3 12 The RF RX 315Mhz The RF RX 315Mhz is an RF receiver It detects any RF signal transmitted via the RF TX 315MHz Type2 from any of the triggering circuits Like its pair this receiver also produced by Cytron The RF RX 315Mhz is operated at 5 0V 0 5V 21 using monolithic super heterodyne receiving operating principle More of its technical specifications can be known by refer
27. with the bedside lamp and a vibrator which was placed under the bed sheet The bedside lamp instead of connected directly to the power source it is connected to the SB1000ss The SB100ss is then connected directly to the home plug The SB1000ss also has a 9V battery backup supply in order to retain the time and alarm settings in case of power failure 2 2 1 2 3 Feature As mentioned before the SB1000ss has three significant features that will help the deaf The first one is the extra loud alarm system which is 113dB louder than normal sound This sound can also be adjusted by the user in terms of its tone and volume This function is suitable for a person who has minimal hearing impairment The second feature which is the vibrator is suitable for those who have a more severe hearing impairment The vibrator a Super Shaker Bed Vibrator model SS12VW which also can be purchased separately used 12V of power supply Figure 2 6 shows the SS12VW Its power supply cord will be connected to the SB1000ss There are two options the user can choose on how the user wants the SS12VW 10 vibrates The first setting called STEADY means the vibrator will have a constant vibration when the alarm goes off The second setting called PULSE will make the vibrator vibrates on and off when the alarm goes off The user can freely choose between these two setting which is the most effective to wake them up 3 Figure 2 6 Super Shaker Bed Vibrator SS12
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