UNIVERSITI TEKNOLOGI MALAYSIA
Contents
1. Further research is recommended to improve the reliability of this project especially in communication This project use wired communication as the medium to communicate due to some limitations of budget and the function which requires no spacious and heavy communication To improve it a wireless communication can be set up to broaden the ability of monitoring system communication in spacious place and wide spectrum For further improvement the research can add some features that enable the master controller to control the sensing element This is to guarantee there is a reliable back up system for this project if any emergency occurs In addition this system was able to monitor and control air condition for various implementations with some system alterations 10 11 12 48 REFERENCES Haines E J 1987 Auto Control of Heating and Air Conditioning Co ed London McGraw Hill Andersen Ib and Korsgaard J 1985 Sensory and Hypereactivity Reactions and Their Significance to Public Health National Institute of Occupational Health Copenhagen Denmark Wobschall D 1979 Circuit Design for Electronic Instrument Analog and Digital Devices from Sensor to Display New York McGraw Hill Nachatelo M July 2002 Weider Publication Gale Group Shahen A 1988 Introduction to Sensor Systems Norwood Artech House Shinskey F 1979 Humidity and Dryer Control Foxbor Mass Harriman K 1995 Humidity Control Desi2. 1 1 Background of Study Environment gives significant impact in human daily live Across the globe environmental issues are critically discussed due to the increase of awareness and responsibility regarding the threats of environment towards public health 2 Quality of the air has significant relation with the quality of environment and weather Since ages people have blamed bad weather for all type of ailments In this project the objective scope has been focused into two factors that will affect public which are percentage of humidity in the air and level of air contaminants Humidity is defined as the amount of water vapor in the air and usually measured in term of Relative Humidity RH Percentage of Relative Humidity is best described as amount of moisture in the air and compared to amount the air can hold at that temperature While air contaminants can be categorized as compounds that may pollute the air With reasons some contaminants are group into several specific categories based on the level of contaminants affecting public health It can be expressed in term of sensor resistance ratio Rs Ro In accordance with this phenomenon where awareness of the importance of air quality control is increasing this project encourages public to be alert with the environment they live in It gives advantage to people who are concern about their health and put efforts in monitoring the environment affected by humidity and contam
3. REVIEW 2 1 Introduction 2 2 Humidity and Gas Sensor Monitoring System 2 3 Definition of Parameters Humidity 2 4 Humidity 2 5 Contaminants Gaseous 2 6 Ideal Environment Standard 2 7 Sensor and Instrumentation 2 7 1 Humidity Sensor 2 7 2 Gas Sensor 2 1 3 40 pins PIC Start up Kit 2 8 PIC Microcontroller 2 8 1 PIC18F452 2 9 Programming Tools 2 9 1 MikroC Software 2 9 2 PIC Kit Programmer 2 9 3 Inter Integrated Circuit Serial Communication 2 10 Indicator 2 11 Components METHODOLOGY 3 1 Introduction 3 2 Research In Phases 3 3 Approches 3 4 Phase 2 Designing Sensor Node 3 4 1 Humidity Sensor HSM 20G 10 10 12 13 13 14 16 17 18 18 20 20 22 22 23 25 26 27 28 29 29 viii 3 4 2 Gas Sensor 3 4 3 Hardware of Humidity and Gas Sensor 3 5 Phase 3 Software 3 5 1 Humidity Sensor Programming 3 5 2 Gas Sensor Programming 3 5 3 Programming for I2C 3 6 Component List and Cost RESULT AND DISCUSSION 4 1 Introduction 4 2 Project Description 4 3 Project Result 4 4 Project Discussion CONCLUSION AND RECOMMENDATION 51 Introduction 5 2 Conclusion 5 3 Recommendation REFERENCES APPENDICES Appendix A HSM 20G User Manual Appendix B TGS 2600 User Manual Appendix C PIC18F452 User Manual 30 33 33 35 38 39 40 41 41 45 46 46 47 48 50 52 54 FIGURE NO 1 1 1 2 1 3 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 2 10 3 1 3 2 3 3 3 4 35 3 6 3 7 3 8 3 9 L
4. Sensor Specification Number Specification Humidity Sensor 1 Circuit voltage range DC 5 0 0 2 V 2 Sensor Resistance Rs 10 k 90k in air 3 Sensitivity change ratio of Rs 0 3 0 6 4 Typical Detection Range 1 10 ppm of H2 The concept is still the same as previous but extra reguirement needed to be considered Gas sensor is measured in term of the ratio between sensor resistance in displayed gas and sensor resistance in fresh air Rs Ro For TGS 2600 Ro is at the range of 32 8 39 6 KQ The calculation involved for converting analog to digital values of gas sensor will be based on the following steps at seen Step 1 Rs Ro can be verified by using the formula given in the datasheet _Ve RkR Vout As mentioned before the value of Rs will vary from 10 90 kQ Vou need to be determined in order to find Rs Step 2 The value chosen for Ro is 32 8 kQ This value meets some condition stated the datasheet where at the gas detection range of 1 10 ppm gas sensor will be more sensitive when sensor resistance ratio is about 0 3 0 6 Rs Ro It can be clearly from Figure 3 7 provided in the datasheet red line area The value of Rs is then divided with the chosen value of Ro When Ro 32 8 kQ 37 Seo E Se Ro 32 8k Ro 32 8k When Ro 39 6 kQ Se aja Se ey Ro 39 6k Ro 39 6k So it can be conclude that the sensor resistance ratio is 0 30 which in the range of 0 3 0 6 if Ro 32
5. Table 2 2 Humidity Sensor Connection Label Description VCC Power supply to the sensor GND The Ground of the sensor Humidity Output The analog output for sensor humidity Sensor For Humidity The sensor to sense humidity 4 pin Header The connector to the cable which connect to microcontroller circuit below HSM20 G is complete with extra features and applications included as Table 2 3 Extra Features and Applications of HSM20 G Applications Extra Features 1 Humidifiers and Dehumidifiers 1 Small size makes it easy to conceal and suit current miniaturization product 2 Air conditioner 2 Compatible with all types of microcontroller makes it reduces the complexity of interfacing 3 Humidity data loggers 3 Very high sensitivity to humidity in the air and makes it reliable 4 Automotive climate control 4 Voltage analog output 16 2 7 2 Gas Sensor The sensing element compromised of a metal oxide semiconductor formed on an alumina substrate of a sensing chip together with an integrated heater In the presence of detectable contaminant gas the sensor s conductivity increases depending on the gas concentration in the air A simple electrical circuit can convert the change in conductivity to an output signal which corresponds to the gas concentration The TGS 2600 has high sensitivity to low concentrations of gaseous air contamin
6. for temperatures gt 25 C TACQ 2 ys TC Temp 25 C 0 05 us C Tc CHOLD RIC RSS RS In 1 2048 120 pF 1 kQ 7 kQ 2 5 kO 1n 0 0004883 120 pF 10 5 kQ In 0 0004883 1 26 us 7 6246 9 61 us 2 us 9 61 us 50 C 25 C 0 05 us C 11 61 us 1 25 ys 12 86 us 2002 Microchip Technology Inc DS39564B page 185
7. indicates as Rs Sensor resistance in displayed gaseous at various concentrations Ro Sensor Resistance in fresh air 2 6 Ideal Environment Standard 13 Table 2 1 shows the specified range for these two elements All the parameters should follow this specification in order to maintain air quality in a closed system Table 2 1 Parameters Specification in Ideal Environment Parameters Specification Humidity 65 85 RH Gas 0 3 0 6 Rs Ro 2 7 Sensors and Instrumentation To design reliable control system for Humidity and Gas Senor Monitoring System in an ideal environment suitable components instrument sensors programming design are needed Presently there are many new developments in electronics that have lead success in designing monitoring system 5 14 2 7 1 Humidity Sensor Humidity sensor is a devise consisting of a special plastic material whose electrical characteristic change according to the amount of humidity in the air Basically this sensor senses the amount of water vapor in air For this project analog input sensor was used HSM 20 G is essential for the objectives and applications where the reading in terms of Relative Humidity was converted into standard voltage output Sensor forl Humidity 4 Pin Header oa Temperature Output Humidity Output GND Figure 2 3 HSM 20 G Connection Based on Figure 2 2 the connection of HSM 20 G is defined as 15
8. microcontroller a Controlling data acquisition in microcontroller b Programming for interfacing the module and sensor Microcontroller communication set up Alerting system when the parameter is out specification Figure 1 1 Block Diagram of Humidity and Gas Sensor Monitoring System in an Ideal Environment 1 5 Outline of Thesis CHAPTER 1 0 This chapter commences with an introduction of humidity and gas sensor monitoring system and automated control system CHAPTER 2 0 This chapter focused on literature review presenting up to data findings and useful theoretical definitions and conventions Besides research related to project is reviewed CHAPTER 3 0 This chapter focuses on the exact steps to be undertaken to complete the project Hardware design and the development of operating system will be examined CHAPTER 4 0 Full system and the results from the performed project will be discussed in detail CHAPTER 5 0 Finally review and summary of project s findings will be concluded in the thesis Recommendation for future development will be included 1 6 Methodology oreparationon and submission FYP 1 report Figure 1 2 Gantt Chart of the Project Schedule for Semester 1 Figure 1 3 Gantt Chart of the Project Schedule for Semester 2 17 Summary of Work This project flows from the sensing data of humidity and gas sensor Analog sensor is used and will indicate as voltage in output Both sensors ar
9. read digital values from 1023 z1 215 lt adc read lt 1023 43 646 4 75 4 75 The differences of this step will be 431 steps Step 3 The operating range of humidity sensor is 20 95 RH with 75 differences It shows that at 20 RH the analog value is 1V while binary is 215 and at 95 RH the analog will be 3V while binary is 646 Step 4 The humidity relation was then obtained as 0 pRa L oi 231 x adc_read 215 20 Step 5 Based on Table 2 1 the RH will be limited to 80 RH which represented a dangerous limit of humidity in the air and automatically set the alarm systems 35 text Humid print string aon LCD 2nd row Ist column LcdS Outirow 1 text ade rd ADC readil get ADC value from 2nd channel iffade rd 15 ade rd gt 646 Led8_Out row 8 ERROR retum humid adc_rd 215 humid 0 17 humid 20 ifihumid 80 4 alert svstem buzzHumiditv 1 LED humid 1 H elsei buzzHumidity 0 LED humid 0 H displaynum humid row 7 display value Led8_Qut row 13 RH Figure 3 6 Source Code for Humidity Sensor 3 5 2 Gas Sensor Programming for Microcontroller For gas sensor the relation will be extracted from the datasheet and focused on some specifications The following calculation will clarify the process to construct an equation for this sensor The main considerations for TGS 2600 are shown by Table 3 2 Refer to Appendix B 36 Table 3 2 Gas
10. 1 42 Project Description This project was based on the objectives stated before which is designing a monitoring system for humidity and gas sensor analog sensor This sensor node will sense analog data convert and displayed into digital Furthermore this system will enable 2 wire communication between devices which is I2C and complete with alarm system After all the phases were completed the whole project can be summarized as shown by Figure 4 1 Indicator LED amp en Micro Controller Task Switch user interface Figure 4 1 Block Diagram of Whole Project 4 3 Project Results This project includes hardware and software parts These two parts were highly dependent where the success of the whole project involves the interfacing between sensor nodes and programming of microcontroller The most critical element in designing hardware is to built up the component connection For the first attempt circuit is set up at proto board based on the theory gathered by some literature reviews done This temporary circuit was use to make 42 sure the connection is working and to avoid errors Then the real connection was sketch using Strip board Designer 1 0 and directly soldered at strip board shown in Figure 4 2 Figure 4 2 The Major Connection of Component To continue with software part some pins of the microcontroller were defined in order to permit programming installation The program was then writte
11. 8 kQ T 2 T z w z s 2 yp cS w a 10 Gas Concentration ppm Figure 3 7 Gas Sensor Sensitivity Characteristic Step 3 The last step will be the determination of Vou Due to the 10 bit of analog to digital converter in PIC18F452 the resolution of 4 75V will be 4 75 Vout ad Creaa X 1023 This equation will complete the finding of Rs which is Vc E R GL F 4 75 aaCread X 1023 Rs ad Cread X R The value of RL is 47kQ stated in datasheet Step 4 Based on Table 2 1 the Rs Ro will be limited to 0 35 represents a dangerous limit of contaminant gaseous in the air and automatically set the alarm system 38 Led8_Out 1 1 Gas text at led first row and column ade rd ADC read 0 get ADC value from 1 channel val unsigned double ade rd rs 1023 47000 val 47000 rs 1000 rs rs 32 8 if rs lt 0 3 5 falert system buzzGas 1 LED gas 1 L J else buzzGas 0 LED gas 0 L J displayNum lt rs 1 5 display value Led8_Out 1 12 Rs Ro 1 J Figure 3 8 Source Code of Gas Sensor 3 5 3 Programming for Inter Integrated Circuit I2C To enable the communication between this project and master controller some programming need to be done A unique address is created for slave in order to communicate with mast
12. CATION FOR WHICH SENSOR HAS NOT BEEN SPECIFICALLY TESTED BY FIGARO 53 Basic Measuring Circuit The sensor requires two voltage inputs heater voltage Vx and circuit voltage Vc The heater voltage Vu is applied to the integrated heater in order to maintain the sensing element at a specific temperature which is optimal for sensing Circuit voltage Vc is applied to allow measurement of voltage Vout across a load resistor RL which is connected in series with the sensor DC voltage is required for the circuit voltage since the sensor has a polarity A common power supply circuit can be used for both Vc and Vu to fulfill the sensor s electrical requirements The value of the load resistor RL should be chosen to optimize the alarm threshold value keeping power consumption Ps of the semiconductor below a limit of 15mW Power consumption Ps will be highest when the value of Rs is equal to RL on exposure to gas bb LA a 5 na w ma all 2 amp S lt A Specifications Model number Sensing element type Standard package Target gases Typical detection range Heater voltage Standard circuit Circuit volta conditions a Load resistance Heater resistance Heater current Electrical characteristics under standard test conditions Heater power consumption Sensor resistance Sensitivity change ratio of Rs Test gas conditions Standard test condit
13. IST OF FIGURES TITLE Block Diagram of Humidity and Gas Sensor Monitoring System in an Ideal Environment Gantt Chart of the Project Schedule for Semester 1 Gantt Chart of the Project Schedule for Semester 2 Relative Humidity in Percentage Humidity Sensor Model HSM 20 G HSM 20 G Connection TGS 2600 Detection of Contaminants Gaseous PIC18F452 pins Programming Diagram Flow Inter Integrated Circuit Bus Light Emitting Diode 16x2 Character LCD Display Buzzer The Methodology Approaches Circuit for Humidity Sensor Bottom View of Gas Sensor Gas Sensor Connection Strip Board Design Source Code for Humidity Sensor Gas Sensor Sensitivity Characteristic Source Code of Gas Sensor Source Code for I2C Unique Address PAGE 11 14 14 16 19 21 23 23 24 24 28 29 31 31 32 35 37 38 38 4 1 4 2 4 3 4 4 4 5 4 6 Block Diagram of Whole Project The Major Connection of Component Complete Hardware of Humidity and Gas Sensor Monitoring System Humidity and Gas reading Enabled Disabled Buzzer Status of Each Sensor xi 41 42 43 43 44 44 TABLE NO 2 1 2 2 2 3 2 4 3 1 3 2 3 3 LIST OF TABLES TITLE Parameters specification in Ideal Environment Humidity Sensor Connection Extra Features and Applications of HSM20 G Features and Application for TGS 2600 Humidity Sensor Specification Gas Sensor Specification List of Components and Cost xii PAGE 13 15 15 17 33 36 39 CHAPTER 1 INTRODUCTION
14. Monitoring System ii Review on sensor node study and comparison study iii Study the related components iv Study the related software Phase 2 Designing Sensor Node i Study the component that will be used ii Finding sources regarding arrangement of component on the strip board iii Including designing hardware for I2C and alert system Phase 3 Designing Programming for Microcontroller 1 Controlling data acquisition in microcontroller ii Programming for interfacing the module and sensor Phase 4 Thesis Writing 28 3 3 Approaches 1 Full understanding the literature review of sensor design to monitor some of the parameters 2 Understand the design method system operation of sensor node 3 Construct the hardware of the Humidity and Gas sensor 4 Programming on data and monitoring system in microcontroller 5 Testing device amp correct errors block diagram flow chart and suitable circuit 6 Finalized the device 7 Prototype practical measurement demonstration amp display result analysis of workable Humidity and Gas Figure 3 1 The Methodology Approach 29 3 4 Phase2 Designing Sensor Node The most complicated part of designing a monitoring system is to design a sensor node Working an analog sensor demands high understanding on how and the range sensor will operates It involved two components for both sensors which is hardware and programming interface Most of the hardw
15. PSZ 19 16 Pind 1 07 UNIVERSITI TEKNOLOGI MALAYSIA DECLARATION OF THESIS UNDERGRADUATE PROJECT PAPER AND COPYRIGHT Author s full name EZLA NAJWA BTE AHYAT Date of birth 29 MAY 2010 Title HUMIDITY AND GAS SENSOR MONITORING SYSTEM IN AN IDEAL ENVIRONMENT Academic Session 2009 2010 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 870529 01 5210 PUAN FATIMAH BINTI MOHAMAD NEW IC NO PASSPORT NO NAME OF SUPERVISOR Date 4 MAY 2010 Date 4 MAY 2010 NOTES 5 If the thesis is CONFIDENTIAL or RESTRICTED please attach with the letter from the organisation with period and reasons for confidentiality or restriction I declare that I have read this work and in my opinion this work is adequate in terms of scope and quality for the purpose of awarding a Bachelor s D
16. ants such as hydrogen and carbon monoxide which exist in cigarette smoke The sensor can detect hydrogen at a level of several parts per million ppm Due to miniaturization of the sensing chip TGS 2600 requires a heater current of only 42mA and the device is housed in a standard TO 5 package Figure 2 4 TGS 2600 Detection of Contaminants Gaseous 17 There are few extra features and application of TGS 2600 shown in Table 2 4 Table 2 4 Features and Application for TGS 2600 Features Applications Low power consumption Air cleaners High sensitivity to gaseous air Ventilation control contaminants Long life and low cost Air quality monitors Small size Uses simple electrical circuit 2 7 3 40 pins PIC Start Up Kit A low cost and yet enhanced technology for save development and soldering time It is designed to offer an easy to start board for PIC MCU user This board comes with basic element for user to begin project development It is compact powerful flexible and robust start up platform 18 2 8 PIC Microcontroller Many related computer systems especially in engineering field used microcontroller The design learning process for beginner can be discovered in many reliable resources making a user friendly component By using microcontroller different methods can be implemented in order to find a solution depending on user s creativity 3 Generally there are many reasons microcon
17. are part is given in the datasheet while for programming some important specification need to be extracted from datasheet and reliable sources 3 41 Humidity Sensor HSM 20 G To enable this sensor to read the moisture water vapor in air is by focusing on the connection part Few things need to be considered such as the external circuit To make sure the relationship between humidity and voltage is linear some components were needed to build the desired circuit as in Figure 3 2 Temperature Output Hunidity RI 5 0VDC 10Kohm 100Kohm Figure 3 2 Circuit for Humidity Sensor 30 In order to use this sensor a connector cable was build to connect the sensor to strip board 4 pin header was connected to the circuit required such that I pin connects to GND Il pin connects to Vcc Il H humidity sensor pin which included 47uF capacitor and 100KQ resistor and connects to microcontroller s I O pin to be set as ADC mode IV T pin not included in this project as the reliability is arguable To ensure the sensor works in the specified range detailed programming must be considered since the sensor is sensitive towards vapor produced by exhalation or heater Refer to Appendix A 3 4 2 Gas Sensor Operation of gas the sensor is the same as the humidity sensor but some consideration needs to be taken in order to interface sensor with programming and hardware In this subtopic most of the discus
18. art is to enable the analog sensor to sense analog data and represent it in digital It can be done with various techniques One of the reliable techniques is to produce a relation between the sensor analog range and microcontroller analog to digital converter ADC specification This relation is based on some calculation and will be clearly explained in the next section 3 5 1 Humidity Sensor Programming for Microcontroller For humidity sensor the relation will be extracted from the datasheet and focused on some specifications The following calculation will clarify the process to construct an equation for this sensor Based on the datasheet of HSM 20G the essentials information is given in Table 3 1 Refer to Appendix A Table 3 1 Humidity Sensor Specification Number Specification Gas Sensor l Input voltage range DC 5 00 2 V 2 Output voltage range DC 1 0 3 0 V 3 Storage RH Range 0 to 99 RH 4 Operating RH Range 20 to 95 100 RH intermittent 34 As mentioned before PIC18F452 is 10 bit analog to digital converter microcontroller and based on the hardware the real input voltage of humidity sensor is 4 75 V Step 1 Since the binary is 10 bit it is equal to 2 1 1023 steps or levels of resolution 4 75V is then divided into 1023 4 75 1023 4 64mV per resolution Step 2 The output voltage range is 1 3 V Thus it will represent as the reference voltage and microcontroller only
19. automatically cleared by hardware when the A D conversion is complete 0 A D conversion not in progress bit 1 Unimplemented Read as 0 bit 0 ADON A D On bit 1 A D converter module is powered up 0 A D converter module is shut off and consumes no operating current Legend R Readable bit n Value at POR ig 2002 Microchip Technology Inc W Wiitable bit Bit is set U Unimplemented bit read as 0 O Bitiscleared x Bit is unknown DS39564B page 181 54 55 PIC18FXX2 REGISTER 17 2 ADCON1 REGISTER RW 0 RWO U 0 U 0 RW0 RW0 RWO RWO ADFM ADCS2 PCFG3 PCFG2 PCFG1 PCFGO bit 7 bit O bit 7 ADFM A D Result Format Select bit 1 Right justified Six 6 Most Significant bits of ADRESH are read as 0 0 Left justified Six 6 Least Significant bits of ADRESL are read as 0 bit 6 ADCS2 A D Conversion Clock Select bit ADCON1 bits in bold Clock Conversion Fosc 2 Fosc 8 Fosc 32 Fre clock derived from the internal A D RC oscillator Fosc 4 Fosc 16 Foscl64 Fre clock derived from the internal A D RC oscillator bit5 4 Unimplemented Read as 0 bit30 PCFG3 PCFG0 A D Port Configuration Control bits Vrert VREF ojoj b gt j gt gt gt oj gt gt gt gt i i isi s olooloslolololo 0 sis 1100 1101 1110 D uu jo jojo D ver ver D A A Analog input D Digital I O C R o
20. d me from the beginning until it finished This project cannot be completed without her supervision and support Lastly a big thanks to my group members Faiz Asraf Saparudin Siti Hasunah Mohamad and Abdul Azim Abdullah for giving me good cooperation and idea to finish this project together Once again thank to all that helps me in this project May Allah bless you all ABTRACT The awareness of air quality control for ideal environment will lessen the risks of increasing environmental threats to public health The relative humidity and level of contaminants gaseous in the air should be monitored in order to achieve the ideal environment This project discussed the monitoring control system for sensing humidity and contaminants gaseous in the air Humidity sensor is a device to detect the percentage of water vapor at a specific temperature in the air which was measured as relative humidity While gas sensor is high sensitivity sensor detects low concentrations of gaseous air contaminants Development in sensor design leads sensor as the main component used to monitor the two factors and microcontroller features as the preferred choice for embedded system which ease the end user to control the system operation Furthermore the control system is designed for monitoring and alerting purposes in order to preserve environmental security and condition Buzzer will produce sounds when relative humidity and level of gaseous are out of the specified
21. e human physically and mentally Based on Argentina study high humidity plays a key role in human health life High humidity contributed to some serious disease as listed below 4 1 Osteoarthritis and Rheumatoid Arthritis 2 Asthma 3 Fatigue 11 Researchers concluded that it is difficult to draw definitive conclusions between arthritis and humidity However some clear up has been made and declared as true which is arthritis patients might be more physically sensitive to humidity changes It affects arthritis symptoms rather than cause of arthritis Nevertheless researches have strong agreement towards the reason why hot humid days cause fatigue Likewise daily activities like washing steaming and drying wet clothes can also contribute to high moisture levels in homes Normally body perspires to cool down when temperatures are high But if the humidity is also high body are trapped in a moist environment where sweat cannot evaporate and escape from skin These causes expend extra energy which can leave the body feeling sluggish or fatigued Furthermore alertness and mental capacity may also be affected In this thesis humidity will be expressed as relative humidity RH which is determined as ratio of the current vapor pressure of water in air to the equilibrium vapor pressure where the gas are saturated at certain temperature It is represented as a percentage Equivalently it is the ratio of the current mass of water p
22. e application please refer Cytron product PR15 which can be found in the web site www cytron com my 52 APPENDIX B TGS 2600 USER MANUAL PRODUCT INFORMATION TGS 2600 for the detection of Air Contaminants Features Applications Low power consumption Air cleaners High sensitivity to gaseous air Ventilation control contaminants Air quality monitors Long life and low cost Uses simple electrical circuit Small size The sensing elementis comprised of a metal oxide semiconductor layer formed on an alumina substrate of a sensing chip together with an integrated heater In the presence of a detectable gas the sensor s conductivity increases depending on the gas concentration in the air A simple electrical circuit can convert the change in conductivity to an output signal which corresponds to the gas concentration The TGS 2600 has high sensitivity to low concentrations of gaseous air contaminants such as hydrogen and carbon monoxide which exist in cigarette smoke The sensor can detect hydrogen at a level of several ppm Figaro also offers a microprocessor FIC93619A which contains special software for handling the sensor s signal for appliance control applications Due to miniaturization of the sensing chip TGS 2600 requires a heater current of only 42mA and the device is housed in a standard TO 5 package The figure below represents typical sensitivity characteristics The figure below represents typica
23. e interfaced to microcontroller PIC18f452 and sensing data is displayed in LCD 2x 16 characters The sensors will work based on the programming in the microcontroller and able to communicate with master controller as the backup monitoring system if any failure happens Alert system is designed and will produce alarm when sensing data out of the specified range CHAPTER 2 LITERATURE REVIEW 2 1 Introduction This chapter will focused on the definition of whole concept of monitoring control system and further details regarding it Explanation on microcontroller sensor and other instrumentation were discussed Related software was determined 2 2 Humidity and Gas Sensor Monitoring System Nowadays the environment is polluted with so many elements which are hazardous to human The most significant pollution is air pollution where the air that human breathes will directly affect the health and living condition Hence drastic action needs to be taken in order to resolve and prevent this problem Two most major elements which give significant effect towards environment are air contaminants gaseous and humidity There are many solutions created to keep the right level of humidity and to detect the existence of contaminants gaseous However alternative system can be design to solve or regulate the value as to minimize the effect of these two elements The automated monitoring control system was designed to overcome this problem and th
24. egree of Engineering Electrical Telecommunication Signature He TN ARE RUKUN Name PUAN FATIMAN BINTI MOHAMAD Date 474 MAY 2010 HUMIDITY AND GAS SENSOR MONITORING SYSTEM IN AN IDEAL ENVIRONMENT EZLA NAJWA BTE AHYAT A report submitted in partial fulfillment of the Requirements for the award of the degree of Bachelor of Engineering Electrical Telecommunication Faculty of Electrical Engineering Universiti Teknologi Malaysia MAY 2010 I declare that this thesis entitled Humidity and Gas Sensor Monitoring System in an Ideal Environment is the result of my own research except as cited in the references This thesis has not been accepted for any degree and is not currently submitted in candidature for any other degree PION AMES PAR AN IR E E A Name EZLA NAJWA BTE AHYAT Date 4 MAY 2010 To my beloved father mother sister and brothers ACKNOWLEGDEMENT In the Name of ALLAH the Most Gracious and the Most Merciful First and foremost I would like to thank Allah because for His bless and guidance I finally finished my final year project successfully Furthermore I would like to thank a lot to my dearest family especially my mom and dad who give me a lot of love and spirit to finish this project till the end I would also like to thank all my friends who gives me idea to solve problem occurs in this project I also like to thank my bighearted supervisor Puan Fatimah Binti Mohamad that has guide
25. er controller This communication is based on the control START and STOP signal by master while slaves simply listen to the bus and react on controls and data sent depending on the unique address SSPADD Addy Get address 7bit Lsb is read wnte flag SSPCONI 0b00110110 li Setto DC slave with 7 bit address PIE1 SSPIE 1 enable SSP interrupts INTCON 0x C0 Figure 3 9 Source Code for I2C Unique Address 3 6 Component List and Total Cost 39 All the components used in this project are listed in order to finalize the total cost Table 3 3 will show the complete components along with each price per item Table 3 3 List of Components and Cost No Component Price Per Unit Quantity Price RM RM 1 Starter Kit Set 39 00 1 39 00 2 PIC18F452 35 00 1 35 00 3 HSM 20G 50 00 1 50 00 4 TGS 2600 46 00 1 46 00 5 PICUSB 49 00 1 49 00 programmer 6 Adapter 15 00 1 15 00 7 LCD 2x16 25 00 1 25 00 character Resistor 0 25 4 1 00 9 Capacitor 0 50 1 0 50 10 Strip Board 4 00 1 4 00 11 Jumper 4 00 4 00 12 LED 0 25 2 0 50 13 Buzzer 3 00 1 3 00 14 Connector 0 50 2 set 1 00 Total 273 00 CHAPTER 4 RESULT AND DISCUSSION 4 1 Introduction This chapter explains about the result achieved in this project and few discussions regarding on problem solving during the process of completing this Final project overview such as block and flow diagram were included 4
26. er volume of gas and the mass per volume of a saturated gas LN actual vapor pressure Relative Humidity RH saturation vapor pressure Figure 2 1 Relative Humidity in Percentage 12 2 5 Contaminants Gaseous Air contaminants give huge impact to the level of human health and directly affected human through the mixture of gaseous that human breath in air contaminants including gaseous liquid or solid state which emitted from many sources in industry mining transportation electricity generation and agriculture Examples of contaminant gaseous are Methane Carbon Monoxide Iso butane Ethanol and Hydrogen However in daily routines human are always exposed and poisoned by Methane and Carbon Monoxide resulting from cigarette smoke and fuel combustion of vehicle These results the suffering respiratory system hospitalization for heart and lung disease asthma and even premature death However this thesis focused on indoor contaminant gaseous as these gaseous are two to five times polluted than outdoor This phenomenon happen when outdoor air contaminants is allowed to bypass filters indoor area potentially disrupt the balance and permit the introduction of excess moisture if access is not controlled It can be monitored by using monitoring control and solved by proper design of Heating Ventilation and Air Conditioning HVAC Systems 10 Air Contaminants will be determined as sensor resistance ratio Rs Ro which
27. f analog input channels of A D voltage references oO o e elelololele elelelo ole z Legend R Readable bit W Wniable bit U Unimplemented bit read as 0 n Value at POR 1 Bit is set O Bit is cleared x Bit is unknown Note On any device RESET the port pins that are multiplexed with analog functions ANx are forced to be an analog input DS39564B page 182 2002 Microchip Technology Inc 56 PIC18FXX2 To calculate the minimum acquisition time Equation 17 1 may be used This equation assumes that 1 2 LSb error is used 1024 steps for the A D The 1 2 LSb error is the maximum error allowed for the A D to meet its specified resolution EQUATION 17 1 ACQUISITION TIME TACQ Amplifier Settling Time Holding Capacitor Charging Time Temperature Coefficient TAMP4 TC 4 TCOFF EOUATION 17 2 A D MINIMUM CHARGING TIME VHOLD VREF VREF 2048 1 e TO Cro1pRic Rss Rs 120 pF 1 kQ Rss Rs In 1 2048 Example 17 1 shows the calculation of the minimum required acquisition time TACQ This calculation is based on the following application system assump tions e CHOLD 120 pF Rs 25kQ Conversion Eror lt 1 2LSb VDD V gt Rss 7kQ Temperature 50 C system max e VHOLD OV time 0 EXAMPLE 17 1 CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME TACQ TAMP TC TCOFF Temperature coefficient is only required
28. gn Guide for Commercial and Institutional Buildings American Society of Heating Refrigerating and Air Conditioning Engineers Sakata S 2002 Removal of Gaseous Contaminants with Various Kinds of Filters Gaseous Contaminants Inorganic Contaminants JPN VOL 76 NO 10 PAGE 941 950 Huadong W and Mel S Odor Based Incontinence Sensor Carnegie Mellon University Pittsburgh IEEE Rafal L and Tiina R 2002 Fungal Fragments as Indoor Air Biocontaminants Morgantown West Virginia Desiree G and Lena K 2005 Perceived Problems and Discomfort at Low Air Humidity Among Worker Occupational Health Care Center Perstorp Support AB Perstorp Sweden IEEE B Martin PIC Microcontroller Elsevier Ltd 2004 13 14 15 16 17 49 MikroC C Complier for Microchip PIC Microcontroller Mikroelektronika User Manual Microchip PICI8FXXX Data Sheet Microchip Technology Inc 2001 HSM 20G User Manual Cytron Technologies TGS 2600 Product Informatio Figaro H Han way PIC Microcontroller An Introduction to Software an Hardware interfacing Delmar Learning 2005 APPENDIX A HSM 20G USER MANUAL Cytron Technologie 2 PRODUCT SPECIFICATION 2 1 The specifications of humidity sensor 50 ROBOT HEAD to TOE Product User s Manual Humidity Sensor No Specification Humidity Sensor 1 Input voltage range DC 5 0 0 2 V 2 Output v
29. id discomfort but for broad range of industries Maintaining good environment quality is essential to closed space system as poor air quality will rapidly reduce health fitness living quality and productivity Hence monitoring on continuous basis is a must because it tends to significantly give huge effect when readings are out of specified range In order to ensure energy efficient and optimized results proper controlled system need to be designed The intelligence of current technologies is applied to revolutionize the system Development in sensor design lead sensor as main component used to monitor some of the parameters and microcontroller features make it preferred choice for embedded control to ease the end user to control the parameters control devices and system operation 1 3 Objectives of Project The objectives of the project are to l 2 1 4 Receive sensing data physical condition from analog sensor Able the communication between microcontroller via inter integrated circuit 12C Activate alert system when result is out of specification Scope of Project The scope of this project is to study investigate and understand humidity and gas sensor monitoring system in an ideal environment The scope involved 1 Review on sensor node study for monitoring system and comparison study Designing sensor node a Component needed b Arrangement of component on the strip board Designing programming for
30. inants gaseous The proper controlled system with continuous and automatic monitoring are the criteria needed to ease the end user The advantage of this system when it is completed with alarm system is the ability to communicate with multi microcontroller and back up control system in case of any failure Besides this simple system can be applied in various implementations with some alteration especially indoor Thus current technologies development and microcontroller may reform the control and operation systems Development in electronics the increase reliability of sensor and instrument help monitoring equipment which maintains the parameter 1 2 Problem Statement The awareness of air quality control for ideal environment will lessen the risks of increasing environmental threats to public health The relative humidity and level of contaminants gaseous in the air should be monitored in order to maintain an ideal environment The common problem results by humidity such as dampness dryness and condensation in surroundings cause discomfort and various problems to public While for contaminants gaseous the effect of it existence is obviously gives severe pollution and adverse consequences to public A recent development in automated control system has increase the demand of various kinds of sensors Humidity and contaminants gaseous are very common in the environment Control and measurement of these elements is important not only to avo
31. ingle integrated environment to develop code for embedded microcontrollers 13 Furthermore highly sophisticated IDE provides the power you need with the simplicity of a Windows based point and click environment MikroC is a powerful feature rich development tool for PICmicros It is designed to provide the users with the easiest possible solution for developing applications for embedded systems without compromising performance or control PIC and C fit together well because PICs are used widely over the world with wide variety of applications while C credited for its efficiency is a natural choice for developing microcontroller applications MikroC provides a successful match featuring highly advanced IDE ANSI compliant compiler broad set of hardware 21 libraries comprehensive documentation and plenty of ready to run example programs MikroC allows you to quickly develop and deploy complex applications I II HI IV VI VIL Write C source code using the built in Code Editor Use the included MikroC libraries to dramatically speed up the development data acquisition memory displays conversions and communication Monitor your program structure variables and functions in Code Explorer Generate commented human readable assembly and standard HEX compatible with all programmers Inspect program flow and debug executable logic with integrated Debugger Get detailed reports and graphs on c
32. input signal to a corresponding 10 bit digital number The A D module has four registers These registers are AD Result High Register ADRESH A D Result Low Register ADRESL AD Control Register 0 ADCONO AD Control Register 1 ADCON1 The ADCONO register shown in Register 17 1 con trols the operation of the A D module The ADCON1 register shown in Register 17 2 configures the functions of the port pins REGISTER 17 1 ADCONO REGISTER RW 0 RW 0 RW 0 RW R W 0 RW 0 U 0 RW 0 ADCS1 ADCSO CHS2 CHS1 CHSO GO DONE ADON bit 7 bit 0 bit 7 6 ADCS1 ADCS0 A D Conversion Clock Select bits ADCONO bits in bold ADCON1 ADCONO z lt ADCS2 gt lt ADCS1 ADCSO gt Glock Conversion 0 00 0 01 0 10 Fosc 32 0 FEI Fre clock derived from the internal A D RC oscillator 1 00 y 01 Fosc 16 1 10 Fosc 64 1 11 Fre clock derived from the internal A D RC oscillator bit5 3 CHS2 CHSO Analog Channel Select bits 000 channel 0 AN0 001 channel 1 AN1 010 channel 2 AN2 011 channel 3 AN3 100 channel 4 AN4 101 channel 5 AN5 110 channel 6 AN6 111 channel 7 AN7 Note The PIC18F2X2 devices do not implement the full 8 A D channels the unimplemented selections are reserved Do not select any unimplemented channel bit 2 GO DONE A D Conversion Status bit When ADON 1 1 A D conversion in progress setting this bit starts the A D conversion which is
33. ions Conditioning period before test The value of power consumption Ps can be calculated by utilizing the following formula Ps Vc Vout Rs Circuit conditions TGS 2600 TO 5 metal can 1 10 ppm of H2 5 0t0 2V DC AC 5 0t0 2V DC Ps lt 15mW Ps lt 15mW aan typical Variable Rs air normal air at 20 2 C 65 5 RH Vc 5 0t0 01V DC VH 5 0 0 05V DC 0 3 0 6 Sensor resistance Rs is calculated with a measured value of Vout by using the following formula VexRL Ri Rs j Vout For information on warranty please refer to Standard Terms and Conditions of Sale of Figaro USA Inc REV 09 01 Structure and Dimensions 09 2 0 2 08 1 a2 7 8 0 5 Side view 10 0 1 0 00 55 0 05 Top view unit mm Pin connection 1 Heater 2 Sensor electrode 3 Sensor electrode 4 Heater FIGARO USA INC 3703 West Lake Ave Suite 203 Glenview Illinois 60025 Phone 847 832 1701 Fax 847 832 1705 e mail figarousa figarosensor com APPENDIX C PIC18F452 USER MANUAL PIC18FXX2 17 0 COMPATIBLE 10 BIT ANALOG TO DIGITAL CONVERTER A D MODULE The Analog to Digital A D converter module has five inputs for the PIC18F2X2 devices and eight for the PIC18F4X2 devices This module has the ADCONO and ADCON register definitions that are compatible with the mid range A D module The A D allows conversion of an analog
34. is system will ease the end user Furthermore the project was designed with alert system where alarm was produced when sensing data are out of the required specification range Communication between microcontrollers was set up via inter integrated circuit U2C Slave mode was activated only if its internal address matches the value sent by the master controller The transferred sensing data is depending on the master acknowledgement In conjunction with that the main key for closed system aquaculture in this thesis is the control system which monitors and regulates the entire main environment discussed 10 2 3 Definition of Parameters Humidity The concentration of water vapor in the air It can be expressed by relative humidity absolute humidity and specific humidity This element depends on the temperature and it gives adverse effect not only towards human health in fact all life aspect Contaminants Gaseous Undesired compound that consist of acid gaseous which may cause or contribute to an increase in deaths or in serious illness or which may pose a present or potential hazard to human health 2 4 Humidity Malaysia is an equatorial country which experience uniform temperature and high humidity level Since ages weather has been blamed for most types of ailment experienced by human Unfortunately most of the public has neglected humidity as one factor contributed to the scenario and worst humidity actually can influenc
35. l temperature and humidity all data having been gathered at standard test conditions see dependency characteristics Again the Y axis is indicated as reverse side of this sheet The Y axis is indicated as sensor sensor resistance ratio Rs Ro defined as follows resistance ratio Rs Ro which is defined as follows Rs Sensor resistance in fresh air Rs Sensor resistance in displayed gases at at various temperatures humidities various concentrations Ro Sensor resistance in fresh air Ro Sensor resistance in fresh air at 20 C and 65 R H Sensitivity Characteristics Temperature Humidity Dependency 10 10 E 3 5 8 1 Air 2 E z Methane 2 5 2 Lal 2 a B Carbon monoxide g 1 RH 3 5 e 5 Iso butane 3 65 pA Ethanol g 95 s 01 Hydrogen Z 2 9 v a wu 0 01 LI l 01 1 10 100 20 10 0 10 20 30 40 50 Gas Concentration ppm Ambient Temperature C IMPORTANT NOTE OPERATING CONDITIONS IN WHICH FIGARO SENSORS ARE USED WILL VARY WITH EACH CUSTOMER S SPECIFIC APPLICATIONS FIGARO STRONGLY RECOMMENDS CONSULTING OUR TECHNICAL STAFF BEFORE DEPLOYING FIGARO SENSORS IN YOUR APPLICATION AND IN PARTICULAR WHEN CUSTOMER S TARGET GASES ARE NOT LISTED HEREIN FIGARO CANNOT ASSUME ANY RESPONSIBILITY FOR ANY USE OF ITS SENSORS IN A PRODUCT OR APPLI
36. n by using C language MikroC MikroC is simple and flexible software that provides information basic tutorial and details libraries which makes it easier to be used This program was then installed to PIC18F452 by using PIC kit programmer Through programming the flow of this system was created Basically this project will sense humidity and contaminants gaseous in the air The monitoring system will continue working either in or out of the specified range Based on the programmed it will automatically monitor show values and conditions whether it is danger or normal readings and finally produced alarm when the values were out of specified range 43 Figure 4 3 Complete Hardware of Humidity and Gas Sensor Monitoring system By pressing reset button the whole system will be reset and display both humidity and gas sensor value If a buzzer sound was generated the sensor which is out of range will be indicated by LED as shown as Figure 4 4 Figure 4 4 Humidity and Gas Reading 44 To enable or disable buzzer user have to push switch as shown in Figure 4 5 ir in Figure 4 5 Enabled Disabled Buzzer Figure 4 6 shows the status of each sensor s reading The user will have to push switch 2 It will display normal in range or danger out range and to choose displayed sensor user have to push switch 2 work in toggle mode Figure 4 6 Status of each sensor Additionally the connection of I2C is set
37. nsumption longer lifetime improved robustness smaller size and faster switching Figure 2 8 Light Emitting Diode 2 Liquid Crystal Display LCD An electronic display device which has a flat panel display type commonly used in digital devices In this project LCD will display the readings and measurement of parameters LCD 2x 16 characters was used 24 Figure 2 9 16x2 Character LCD Display 3 Buzzer Electronic device which is defined as audio signaling device Buzzer functioned as alert system and automatically produced sound when reading is out of the specified range Figure 2 10 Buzzer 25 2 11 Components Several extra components were used to design this project All the listed component is a compliment to both sensors in order to make it regulates reading and measurement I Resistor 100kQ and 47kQ Il Capacitor 47uF CHAPTER 3 METHODOLOGY 3 1 Introduction The project will be conducted in phases and explained in this chapter This chapter will give the sufficient detail of the exact steps which act as a guidance in order to complete this project The discussion continues with specific block diagram which include the component that will be used to complete the hardware parts Lastly this chapter shows the flow chart that explained the whole system 27 3 2 Research in Phases Phase 1 Literature Review Done in chapter 2 1 Study the concept of Humidity and Gas Contaminants
38. ode statistics and assembly listing Debugger Microcontroller Compiler PIC18F452 Figure 2 6 Programming Diagram Flow 22 2 9 2 PIC Kit Programmer In order to load the program in the microcontroller this software was used This software will load all program made into internal memory of PIC18F452 Once the HEX file was created in MikroC this file will then be loaded into PIC18F452 using PIC Kit2 2 9 3 Inter Integrated Circuit I2C Serial Communication RC interface one or more microcontroller and peripherals in embedded system for example exchanging data with master controllers via single connection 10 It has two active wires which are serial data line SDA and serial clock line SCL These two buses will synchronize mater slave communication by using software I2C is suitable for communication between separate microcontroller boards and provide simple hardware design but more complex in the software Every devices have it own unique address and can act as a receiver or transmitter depending on the function I2C is a multi master bus which indicates that more than one ICs can initiate data transfer and called as Bus Master while other ICs as Bus Slaves 23 Figure 2 7 Inter Integrated Circuit Bus 2 10 Indicator 1 Light Emitting Diode LED Device that act as receiver that indicates sensor node and overall system is working by emitting low intensity light This semiconductor diode has lower energy co
39. oltage range DC 1 0 3 0 V 3 Measurement Accuracy 5 RH 4 Operating Current Maximum 2mA 5 Storage RH Range 0 to 99 RH 6 Operating RH Range 20 to 95 100 RH intermittent 7 Transient Condensation lt 3 RH 8 Temperature Range Storage 20 C to 70 C Operating OTC to 50 C 9 Hysteresis RH 25 C MAX 2 RH 10 Long Term Stability typical drift per year 1 5 1 Linearity Linearity 2 Time Response 63 step change 1 min 3 Dimensions L W 30mm 22mm Table 2 1 2 2 Pin Definitions and Ratings Pin Name Function GND Connects to Ground H Humudity Output Voltage analog output Vee Connects to Vee 5V T Temperature Output Voltage analog output Note Please refer Getting Started for the pin connection Table 2 2 51 Cytron ROBOT HEAD to TOE Technolog Product User s Manual Humidity Sensor 3 ATuF 10V Figure 4 4 Figure 4 4 shows the connection of humidity sensor to PIC microcontroller which is PIC16F876A The voltage supply VCC of the circuit is 5V The voltage analog output of humidity H is connected to RAO ANO while the voltage analog output of temperature T is connected to RAI ANI However user is free to choose any type of microcontroller just have to make sure that both of the voltage analog outputs of humidity sensor are connected to the ADC Analog Digital Convector pin of that particular microcontroller For more details of exampl
40. range vi ABSTRAK Kesedaran terhadap kawalan kualiti udara untuk persekitaran ideal dapat membantu mengurangkan risiko dan ancaman persekitaran terhadap kesihatan orang awam Kelembapan bandingan dan tahap gas gas beracun di udara perlu dikawal bagi mencapai persekitaran ideal Projek ini membincangkan tentang sistem pantauan dan kawalan untuk kelembapan dan gas gas beracun di udara Sensor kelembapan ialah alat yang digunakan untuk mengesan kandungan wap air di udara pada suhu tertentu Ia diukur dalam peratus kelembapan bandingan Sementara itu sensor gas ialah pengesan yang sensitif bagi mengesan kewujudan gas gas beracun yang berketumpatan rendah Kemajuan dalam bidang alat pengesan menyebabkan ia terpilih untuk menjadi komponen utama bagi mengesan kedua kedua elemen Ciri ciri mikropengawal akan memudahkan lagi pengguna untuk mengawal operasi sistem Selain itu projek ini dilengkapi oleh sistem kawalan Penggera akan mengeluarkan bunyi jika elemen di luar julat dalam spesifikasi bagi mengawal keselamatan dan keadaan persekitaran CHAPTER TABLE OF CONTENTS TITLE DECLARATION OF THESIS DEDICATION ACKNOWLEDGEMENT ABSTRACT ABSTRAK CONTENTS LIST OF FIGURES LIST OF TABLES INTRODUCTION 1 1 Background of Study 1 2 Problem Statement 1 3 Objective of Project 1 4 Scope of Project 1 5 Outline of Thesis 1 6 Methodology 1 7 Summary of Work PAGE ii iii iv vi vii xii aUa A A Q vii LITERATURE
41. sion is focused on hardware interfacing part Figure 3 3 Bottom View of Gas Sensor 31 Gas sensor needs a voltage of 5V to operate and it resistances changes with gas concentration and act as a potential meter The connection of each pin is determined as Figure 3 4 Some of specification is essential to continue with next step which is programming part and react significantly with methane in the cigarette lighter Refer to Appendix B Figure 3 4 Gas Sensor Connection 32 3 4 3 Hardware of Humidity and Gas Sensor Monitoring System After considering all the important software criteria the flow of project continues with the construction of hardware The connection of sensor nodes and the related component was built using strip board Before components were placed the strip board design was sketched by using Strip board Designer 1 0 Figure 3 5 Strip Board Design This design work as a connection reference needed for hardware including sensor node interfacing with microcontroller I2C connection and alert system Most of the component in the designer does not represent the actual components due to the software limitations However the main concern is the exact holes connection By following the layout the complete design was soldered 33 3 5 Phase 3 Software Programming for Microcontroller This section will specifically discuss the methodology to interface the sensor and hardware module The most important p
42. synchronous Receiver Transmitter USART SCI Furthermore PIC18F452 is compatible 10 bit Analog to Digital Converter module A D with fast sampling rate and conversion available during SLEEP suits the demand of this project 14 MCLRVPPr e J RB7 PGD RAO ANO RA1 AN1 RA2 AN2 VREF RA3 AN3 VREF RA4 TOCKI RAS AN4 SS LVDIN REO RD ANS RE1 WR AN6 RE2 CS AN7 VDD Vss OSC1 CLKI OSC2 CLKO RAG RCOMT10SO T1CKI RC1 T10SI CCP2 RC2 CCP1 RC3 SCKISCL COON DO amp WH N Ww o 9 a PIC18F452 RB6 PGC RB5 PGM RB4 lt RB3 CCP2 RB2 INT2 gt RB1 INT1 RBO INTO VDD VSS RD7 PSP7 RD6 PSP6 RDS PSPS RD4 PSP4 RC7 RXIDT e RCG TX CK e RC5 SDO RC4 SDI SDA RDO PSPO RD1 PSP1 J 21 LJ gt RD2 PSP2 Figure 2 5 PIC18F452 Pins 20 2 9 Programming Tools I PIC is programmed by using MikroC software I Program written and convert into machine code II PIC is placed in special program a unit which is attached to the host computer IV Program downloaded via PIC kit V PIC is placed in the application circuit 2 9 1 MikroC Software MikroC is powerful and user friendly C compiler for PIC microcontroller form Mikroelektonika This software program runs on a PC to build up applications for PIC microcontroller families It is called an Integrated Development Environment or IDE because it provides a s
43. troller is chosen as the brain of the system It is due to the low cost small packaging low power consumption reprogrammable easy integration with custom circuits and compatible to software development and debugging tools In this project microcontroller will act as the main component in embedded system because of it multi tasking capabilities processing data and the ability to control the functionality of other device 2 8 1 PIC18F452 PIC18F452 is chosen due to it characteristic that is suitable to this project application Based on the data sheet this microcontroller has 32kb internal flash program memory which is reprogrammable and suitable for prototyping Besides that it compatibility to use the same source code with the PIC16 and PIC17 instruction sets makes the references broaden This PIC included with internal 10 bit Analog Digital converter that allows the converting process of analog data from sensors into digital signal 19 Other brilliant features of PIC18F452 have 75 instruction sets need to be learn and low power high speed FLASH EEPROM technology This chosen PIC consist of up to 33 general purpose I O pins with port A B C D E that will reduce the complexity of the system which is suitable for the beginner There are also peripheral features that enable the communication between PIC and other devices including Synchronous Serial Port SSP with SPI Master mode and I2C Master Slave and Universal Synchronous A
44. up sensors will communicate or transfers data if requested by master while sensing the data at the same time 45 44 Project Discussion No project will work without any mistakes and errors To achieve this certain action was taken The completed hardware for sensor monitoring was checked by using continuity test This is to ensure the connection done was accurate and the project is working with the specification The programming need to be totally reviewed to ensure no bugs distracts the whole system CHAPTER 5 CONCLUSION AND RECOMMENDATION 5 1 Introduction This section will conclude the whole project and future recommendations for students or individual who is interested in continuing this project as their research 5 2 Conclusion Sensor technologies are developing fast with time and innovative technology This field is one of the most interesting area to be discovered continuously So many new sensor designs will come out and develop in future hence increasing the competitiveness between researchers 47 This project is a minor contribution to instill the interest of people It also gives a very basic understanding which will be a good learning process to the beginner The hardware and software part of this project is working based on the objectives mentioned before and based on the conduct test or experiments held towards the end this project the results are stable and working as it should be 5 3 Recommendation
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