KyawThuYaThein FYP

Real-Time Signal Analysis with LabView/Micro-processor

ENG 499 CAPSTONE PROJECT COURSE A project report submitted to SIM University in partial fulfillment of the requirements for the degree of Bachelor of Electronic Engineering

STUDENT:

Kyaw Thu Ya Thein (H0705065)

SUPERVISOR:

Mr. Qian Ji

PROJECT CODE: ENG499

Bachelor of Electronic Engineering SCHOOL OF SCIENCE AND TECHNOLOGY SIM UNIVERSITY

November November 2010



ACKNOWLEDGEMENTS Firstly, Firstly, I would like to express my sincere and heartfelt appreciation to my project supervisor, supervisor, Mr. Qiang Ji for his exceptional guidance, invaluable advice and wholehearted support in matters of practical and theoretical nature throughout the project. His constant time check and meet ups had certainly motivated me in the the completion of the project. Although he have been resigned from Uni Sim , he gave guidance through per mail and lead me to the correct part of project scope. scope.

Throug Throughou houtt my thesisthesis-wri writing ting period, period, he provid provided ed encour encourage agement ment,, sound sound advice, advice, good good teaching, good company, and lots of good ideas. Thanks to him for his tolerance and patience to all my queries regardless be it an email or phone call, he had almost response to it with no delays. The completion of the Final Year Project would not be possible without his excellence supervision.

I am gratefully appreciative of UniSIM capstone project instructors particularly Dr. Lim Teik Cheng for providing me the opportunity to study in Microcontroller application. I would like to thank UniSIM for providing the financial means and laboratory facilities.

Lastly, I would like to thank all the lectures and friends in UniSIM and also to my loved ones who have given their fullest support in this Final Year Project.

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ACKNOWLEDGEMENTS Firstly, Firstly, I would like to express my sincere and heartfelt appreciation to my project supervisor, supervisor, Mr. Qiang Ji for his exceptional guidance, invaluable advice and wholehearted support in matters of practical and theoretical nature throughout the project. His constant time check and meet ups had certainly motivated me in the the completion of the project. Although he have been resigned from Uni Sim , he gave guidance through per mail and lead me to the correct part of project scope. scope.

Throug Throughou houtt my thesisthesis-wri writing ting period, period, he provid provided ed encour encourage agement ment,, sound sound advice, advice, good good teaching, good company, and lots of good ideas. Thanks to him for his tolerance and patience to all my queries regardless be it an email or phone call, he had almost response to it with no delays. The completion of the Final Year Project would not be possible without his excellence supervision.

I am gratefully appreciative of UniSIM capstone project instructors particularly Dr. Lim Teik Cheng for providing me the opportunity to study in Microcontroller application. I would like to thank UniSIM for providing the financial means and laboratory facilities.

Lastly, I would like to thank all the lectures and friends in UniSIM and also to my loved ones who have given their fullest support in this Final Year Project.

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ABSTRACT Any Any elect electric rical al and and mecha mechanic nical al syst system em such such as comp comput uter er,, powe powerr supp supply ly unit, unit, ampli amplifie fier, r, machinery machinery room, vehicle interior generates heat during its operation. Most of the electrical and mechanical mechanical system are installed installed and assembled assembled inside some of casing, casing, housing or even a room to protect it from being touch or expose to unnecessary contact which may cause injury to the operator or malfunction to the system. The casing serve as protective housing for the system but it also also accumulate accumulate and and trap heat within within the system without without proper proper ventilation. ventilation.

An automatic Heat ventilation system model is build and studied the nature of the HVAC system. The model is using two temperature sensors one for exterior environment temperature and one for system interior temperature, heat source, LM 3S8962 Evaluation Board used as temperature acquisition and NI LabView were used as processing platform that try to match and maintain the interior temperature to the exterior temperature using ventilation fan. Thus the interior temperature set point is determined by the exterior environment temperature.

The purpose of creating this project is to reduce comfortable and reliable environment, with minimum minimum cost, with with user-frie user-friendl ndly y interfac interface, e, with with less less comple complexity xity and with with effectiv effectivee area area coverage from the components that are easily available in the market.

The experiments are carried out and monitored the system model temperature. It was observed that during the heat source is turned on; the minimum temperature difference that can go down is 3 degree. And the temperature goes down within 7 minutes. When the heat source is off, it matches to exterior within 2 minutes.



List of Figures Figure 1.1: Proposed Design...........................................................................................................3 Figure 2.1: Example of contact type sensor...................................................................................5 Figure 2.2: Example of Op-amp configuration..............................................................................7 Figure 2.3: LM3S8962 Evaluation Board Block Diagram..........................................................11 Figure 2.4: ARM Cortex M3 Architecture...................................................................................13 Figure 3.1: Gantt chart..................................................................................................................19 Figure 4.1: System Block Diagram..............................................................................................20 Figure 5.1: Stellaris LM3S8962 Evaluation Board Layout.........................................................22 Figure 5.2: Schematic for external sensor board..........................................................................24 Figure 5.3: Voltage regulator symbol...........................................................................................25 Figure 5.4: Schematic for checking regulator quality............................................................... ..26 Figure 5.5: Temperature sensor configuration.............................................................................27 Figure 5.6: Capacitor configuration..............................................................................................30 Figure 5.7: Diode specification.....................................................................................................31 Figure 5.8: Darlington transistor symbol......................................................................................33 Figure 5.9: Darlington transistor configuration............................................................................33 Figure 5.10: Internal Sensor board...............................................................................................35 Figure 6.1: Block diagram of conversion.....................................................................................36 Figure 6.2: Front panel of conversion..........................................................................................37 Figure 6.3: Internal Thermometer................................................................................................37 Figure 6.4: Block diagram of External Thermometer..................................................................38 Figure 6.5: Block diagram of Internal Temperature Monitor......................................................38 Figure 6.6: Block diagram of External Temperature Monitor.....................................................39 Figure 6.7: Block diagram of Internal and External Temperature...............................................39 Figure 6.8: Block diagram of Fan out..........................................................................................40 Figure 7.1: Final Front-panel for blinking LED VI.....................................................................42 Figure 7.2: Final Block Diagram for blinking LED VI...............................................................42 Figure 7.3: Setting Build Specification........................................................................................43 Figure 7.4: Blinking of LED on Evaluation board.......................................................................43 Figure 7.5: Testing on incoming voltage......................................................................................44 Figure 7.6: Output Voltage after LM7805...................................................................................44

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Figure 7.7: Output Voltage after LM3940...................................................................................45 Figure 7.8: Output Voltage of External/Outside Temperature sensor.........................................45 Figure 7.9: Output Voltage of Internal Temperature sensor........................................................46 Figure 7.10: Internal Thermometer..............................................................................................47 Figure 7.11: External Thermometer.............................................................................................48 Figure 7.12: Internal Temperature History in Fahrenheit............................................................48 Figure 7.13: Internal Temperature History in Celsius.................................................................49 Figure 7.14: External Temperature History in Fahrenheit...........................................................49 Figure 7.15: External Temperature History in Celsius................................................................50 Figure 7.16: Internal temperature monitor...................................................................................50 Figure 7.17: External temperature monitor..................................................................................51 Figure 8.1: Temperature history of inside and outside of the system model...............................52 Figure 8.2: The temperature difference after heat source is ON..................................................53 Figure 8.3: The minimum temperature difference.......................................................................53 Figure 9.1: Wrong Connection circuit for fan output..................................................................56 Figure 9.2: Corrected circuit for fan output.................................................................................56

List of Tables Table 3.1: Total Cost for Project.................................................................................................16 Table 3.2: Detail Project Plan.......................................................................................................18 Table 5.1: LM35 Sensor Feature..................................................................................................27 Table 5.2: Resistor-band configuration........................................................................................29 Table 5.3: Diode Features.............................................................................................................31 Table 9.1: the ADC input Voltage................................................................................................55

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Table of Contents

ACKNOWLEDGEMENTS............................................................................................................ . i ABSTRACT.................................................................................................................................... ii List of Figures............................................................................................................................... . iii List of Tables .............................................................................................................. ................... iv Chapter 1: Project Definition....................................................................................................... ... 1 1.1 Project Objective............................................................................................. ..................... 1 1.2 Project Scope ........................................................................................................ ................ 1 Project Background............................................................................................... ..................... 2 1.4 Proposed Approach and method to be employed................................................................. 2 Chapter 2: Review of theory and previous work ........................................................................... 4 2.1 Overview of Heat Ventilation system .................................................................................. 4 2.2 Overview of Temperature Sensor......................................................................................... 4 2.3 Overview of Operational Amplifier ..................................................................................... 7 2.4 Overview of FFT nature.......................................................................................... ............. 8 2.5 Overview of Lab View............................................................................................ ............. 8 2.5.1 Principles of LabVIEW................................................................................... .............. 9 2.6 Overview of Stellaris LM 3S8962 Evaluation Board ....................................................... 11 2.7 Features of LM3S8962 Micro controller ........................................................................... 12 ...................................................................................................................................................... 13 2.8 ARM® Cortex™-M3 processor......................................................................................... 13 2.8.1 Key Benefits ............................................................................................ .................... 14 Chapter 3: Project Management ................................................................................. .................. 15 3.1 Required Resources............................................................................................... ............. 15 3.1.1 School Facility................................................................................................... .......... 15 3.1.2 Internet Broadband .................................................................................... ................ 15 3.1.3 Expenditure (COST) ................................................................................................... 16 3.2 Planning ............................................................................................................................. 16 3.3 Cost for Development......................................................................................................... 16 3.4 Project Task and Schedule ................................................................................................ 17 Chapter 4: Overall System Design ............................................................................. .................. 20 Chapter 5: Hardware Design and Specification........................................................................... 21 5.1 Stellaris LM 3S8962 Evaluation Board ............................................................................ 21



5.1.1 LM3S8962 Microcontroller......................................................................................... 23 5.1.2 Clocking.................................................................................................................... ... 23 5.1.3 Reset............................................................................................................................. 23 5.1.4 Power Supplies ......................................................................................... ................... 23 5.2 External Sensor Board................................................................................................. ....... 23 5.2.1 Voltage Regulator................................................................................................... .... 24 5.2.2 Measures of regulator quality................................................................................... ... 25 5.2.3 LM35 - Precision Centigrade Temperature Sensor.................................................... 26 5.2.4 Ohm's law................................................................................................ .................... 28 5.2.5 Four-band resistors ...................................................................................... ................ 28 5.2.6 Capacitor............................................................................................................... ....... 29 5.2.7 Diode.......................................................................................................................... .. 30 5.2.8 Darlington transistor............................................................................................ ........ 33 5.3 Internal Sensor Board.............................................................................................. .......... 35 Chapter 6: Software Development ............................................................................................... 36 6.1 Conversion of Degree Celsius to Fahrenheit .................................................. ................... 36 6.2 Internal Thermometer................................................................................................. ........ 37 6.3 External Thermometer................................................................................................... ..... 38 6.4 Internal Temperature Monitor .................................................................................. .......... 38 6.5 External Temperature Monitor...................................................................................... ..... 38 6.6 Internal and External Temperature Monitor................................................... ................... 39 6.7 Fan Out ....................................................................................................... ...................... 40 Chapter 7: Integration and Testing .................................................................................. ............. 41 7.1 LM3S8962 Evaluation board Testing................................................................................ 41 7.2 Hardware Testing....................................................................................... ........................ 44 44 7.3 Software Testing............................................................................................................. .... 47 7.3.1 Internal Thermometer.......................................................................................... ........ 47 7.3.2 External Thermometer............................................................................................. .... 47 7.3.3 Internal Temperature Monitor ........................................................................... .......... 48 7.3.4 External Temperature Monitor .............................................................................. ...... 49 7.3.5 Internal and External Temperature Monitor............................................................... 50 Chapter 8: Simulation and Result........................................................................................... ...... 52 Chapter 9: Problem Encountered ................................................................................................. 55 9.1 Choice of temperature sensor.................................................................................... ......... 55 9.2 Choice of Light bulb........................................................................................................... 56 9.3 Connection on the Darlington transistor ............................................................................ 56 Chapter 10: Conclusion and Recommendation............................................................................ 57 10.1 Conclusion.......................................................................................................... .............. 57

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10.2 Future recommendations.................................................................................... .............. 57 Chapter 11: Critical Review and Reflection................................................................................. 58 11.1 Review and Reflections............................................................................................... ..... 58 11.2 Skills Review............................................................................................................ ........ 59 References............................................................................................................................. ........ 60 APPENDIXES............................................................................................................... ............... 61

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PART 1 Chapter 1: Project Definition 1.1

Project Objective

The main objective is to build a Remote Radiant room temperature monitoring system based on signal capturing and analysis with Lab View This project requires the following tasks to achieve the main objective. •

Evaluate the different types of temperature sensor on the market and choose one as a platform to design a Remote Temperature& Energy monitor

•

To capture external analogue signal, do the real time signal processing (FFT etc).

•

To understand the various algorithms and functional of Signal

•

Development of Temperature control function on laptop with Lab view.

The expected Outcome

Waveform from functional Temperature Sensor will be sampled at the controller and do the assessment on Lab View software. Then user-programmable function will process the analog signal and resulting temperature and temperature chart will be displayed on PC.

1.2

Project Scope

This project requires the following tasks to achieve the main objective.

•

Evaluate the different type of temperature sensors, such as thermocouples, RTD and themistors on the market and choose one as a platform to measure the temperature

•

To understand the various sampling, triggering methods and FFT transform algorithms, functional blocks of digital oscilloscope

•

Implement the algorithms and functions LM 3S8962 Evaluation Board

•

Design interface program for data transfer between Evaluation Board and computer

•

Development of Temperature reading on Lab view

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Project Background The automatic heat ventilation system is the primary element in controlling environmental temperatures of an enclosed area. The system will also provide fresh outdoor air to the enclosed area to dilute any contaminants in the air and to increase circulation. Systems will control and adjust temperatures to improve comfort and increase efficiency. By performing tests on the Remote Radiant system and improving the control, you will be able to optimize the performance of the system, provide the highest level of environmental comfort and increase energy efficiency.

There are several benefits associated with building a test and control unit for your Heating, Ventilation and Air-Conditioning (HVAC) system. First and foremost, the objective is to create an optimal working environment. If the HVAC system is to be used to control the environment of an office building, you want to ensure that the workers are comfortable at all times of the day. An optimized HVAC system will properly control temperature, reduce humidity, and circular air throughout the building. [17]

HVAC systems make up approximately 50% of energy usage in commercial and residential buildings. By testing the HVAC system, you will be able to determine if there are inefficient areas of the environment. Possible areas where the heating is lost or the cooling does not reach an important area, thus causing the system to work harder to meet desired set points. Being able to test your system, you can create custom controls that will increase reliability and performance of your system therefore making it more energy efficient. [14]

1.4

Proposed Approach and method to be employed

The system should be low cost, small size and easy to implement which will help to use these monitoring system in household. An Automatic Heat Ventilation System will be designed to ventilate heat air that accumulated or generated within a system housing interior to improve thermal management of the system based on natural environmental cooling concept where the cooling factor or the interior temperature set point is determined by it exterior surrounding environment temperature.

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The prototype system consists of two analog semiconductor temperature sensors, a LM3S8962 evaluation kit, and a computer with LabVIEW and ventilation fan. The system use one temperature sensor to sense the interior temperature of a given system and another sensor to measure the exterior environment temperature than the heat ventilation system try to match the interior temperature to the exterior temperature by activating the ventilation fan to exhaust the heat air out from the system interior housing. Hence the system ventilation temperature set point is determined by the exterior temperature this allows the heat ventilation system to react and adapt to the environment temperature changes.

NI LabVIEW will be used as processing platform that try to match and maintain the interior temperature to the exterior temperature using ventilation fan. Thus the interior temperature set point is determined by the exterior environment temperature.

A small system model will be built to simulate a system that generates internal heat within a system. The system model was build with the dimension of 21cm x 12cm x 9cm. A 100W light bulb was use as internal heat source to simulate convection heat generate by the system. Two ventilation fans was place on both end of the model to exhaust heat out from the system.

. Figure 1.1: Proposed Design

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Chapter 2: Review of theory and previous work 2.1

Overview of Heat Ventilation system

Basically any electrical and mechanical system such as computer, power supply unit, amplifier, machinery room, vehicle interior generates heat during its operation. Most of the electrical and mechanical systems are installed and assembled inside some sort of casing, housing or even a room to protect it from being touch or expose to unnecessary contact which may cause injury to the operator or malfunction to the system.

The casing serve as protective housing for the system but it also accumulate and trap heat within the system without proper heat ventilation. Heat Ventilation Air Conditional (HVAC) system is a common solution to a room based system, which allow any desired temperature control regardless of its surrounding and exterior environment temperature.

HVAC system are usually costly because of additional power consumption due to the use of air conditional unit for heat exchanger process, thus it is not energy efficient. Fan based heat ventilation system with preset temperature set point is a common solution to smaller casing or housing based electrical system. The preset temperature set point is usually fixed and does not change even the system is place and operate in a cooler or hotter environment. [17]

The fan based heat ventilation system using natural environmental cooling concept where the cooling factor or the interior temperature set point is determine by it exterior surrounding environment temperature this allows the temperature set point to change and adapt to the surrounding environment temperature that the system is place and operate. This allows better thermal management in term of cooling efficient while place and operate in a cool or air conditional environment and energy efficient while place and operate in a warm environment.

2.2

Overview of Temperature Sensor

Big differences exist between different temperature sensor or temperature measurement device types. In HVAC system, most sensors are used to detect Temperature or heat. These types of sensors vary from simple ON/OFF thermostatic devices which control a domestic hot water

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system to highly sensitive semiconductor types that can control complex process control plants. Temperature Sensors measure the amount of heat energy or even coldness within an object or system, and can "sense" or detect any physical change to that temperature.

There are many different types of Temperature Sensors available and all have different characteristics depending upon their actual application. Temperature sensors consist of two basic physical types:

Contact Types

These types of temperature sensors are required to be in physical contact with the object being sensed and used conduction to monitor changes in temperature. They can be used to detect solids, liquids or gases over a wide range of temperatures.

Non-contact Types

These types of temperature sensors detect the Radiant Energy being transmitted from the object in the form of Infra-red radiation. They can be used with any solid or liquid that emits radiant energy.

Figure 2.1: Example of contact type sensor

Analogue sensors tend to produce output signals which are slow changing and very small in value so some form of amplification is required. Also analogue signals can be easily converted

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into Digital type signals for use in microcontroller systems by the use of Analogue to Digital Converters.

Selecting the right temperature sensor depends on the process being measured, the temperature range stipulated, the response time desired, the accuracy required, and the operating environment encountered. Another important factor to consider is price, which varies with the accuracy rate and the mounting style of the device. Temperature sensors generate output signals in one of two ways: through a change in output voltage or through a change in resistance of the sensor's electrical circuit. Thermocouples and IR devices generate voltage output signals. RTDs and thermistors output signals via a change in resistance.

Thermocouples

These sensors have the widest operating range and are best suited for high temperatures. Thermocouples of noble metal alloys can be used for monitoring and controlling temperatures as high as 3100ºF. These devices are also best for applications requiring miniature sensor designs.

RTDs.

These are precision temperature-sensing devices. They're the ones to use when applications require accuracy, long-term electrical (resistance) stability, element linearity, and repeatability. The devices can work in a wide temperature range—some platinum sensors handle temperatures from 328ºF to 1202ºF.

Thermistors

These sensors are sensitive to small temperature changes. These devices are best for lowtemperature applications over limited ranges. The element is small-thermistor beads can be the size of a pinhead for point sensing-and tends to become more stable with use. Depending on the grade and price of the thermistor performance can range anywhere from low accuracy to accuracy matching high-end RTDs.

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2.3


Overview of Operational Amplifier

Op-amps can be used to provide amplification of signals when connected in either Inverting or Non-inverting configurations. The very small analogue signal voltages produced by a sensor such as a few mill volt’s can be amplified many times over by a simple op-amp circuit to produce a much larger voltage signal of say 5v or 10v that can then be used as an input to a microprocessor based system.

Then when using sensors, generally some form of amplification (Gain), impedance matching or perhaps phase shifting may be required before the signal can be used and this is conveniently performed by Operational Amplifiers. Also, when measuring very small physical changes the output signal of a sensor can become "contaminated" with unwanted signals or voltages that prevent the actual signal required from being measured correctly. These unwanted signals are called "Noise".

This Noise or Interference can be either greatly reduced or even eliminated by using signal conditioning or filtering techniques. By using Low Pass, High Pass or even Band Pass filters the "bandwidth" of the noise can be reduced to leave just the output signal required.

For example, many types of inputs from switches, keyboards or manual controls are not capable of changing state rapidly and so Low-pass filter can be used. When the interference is at a particular frequency, for example mains frequency, narrow band reject or Notch filters can be used. Where some random noise still remains after filtering it may be necessary to take several samples and then average them to give the final value so increasing the Signal-to-Noise ratio.

Figure 2.2: Example of Op-amp configuration

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2.4


Overview of FFT nature

A real time FFT analyzer is a measurement apparatus that continuously transforms a signal under test by the process in real time without dead time in order to extract the frequency domain component from the signal to analyze it. It is an efficient algorithm to compute the discrete Fourier transform (DFT) and it’s inverse. There are many distinct FFT algorithms involving a wide range of mathematics, from simple complex-number arithmetic to group theory and number theory; An FFT is a way to compute the same result more quickly: computing a DFT of N points in the obvious way, using the definition, takes O (N 2) arithmetical operations, while an FFT can compute the same result in only O (N log N) operations. The difference in speed can be substantial, especially for long data sets where N may be in the thousands or millions—in practice, the computation time can be reduced by several orders of magnitude in such cases, and the improvement is roughly proportional to N/log(N).

2.5

Overview of Lab View

Lab view (Laboratory Virtual Instrument Engineering Workbench) is one of the more common software packages used to automate data acquisition developed by National Instruments. It is a simple way to set up and run numerous instruments on a PC. The user of the virtual instrument can change its function at will to suit a range of applications. The virtual instrument with the right algorithm can analyze and display information in anyway the user wants.

Lab view was focused at providing a graphical tool for measurement task in the area of laboratory automation. It is a language based on data driven dataflow language plus additional graphical control flow constructs such as loop and additional codes to create a graphical editing and multitasking execution environment. The software was aimed at non-programmers in mind. Each virtual instrument has its own user interface. Programming languages was also substituted by graphical programming. From the traditional edit/compile/link/run sequence is being replaced by the draw/run cycle. Idea of graphical programming started with flow diagrams then to loops. [5]

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Real-Time Signal Analysis with LabView/Micro-processor 2.5.1


Principles of LabVIEW

Dataflow Programming

The programming language used in LabVIEW, also referred to as G, is a dataflow programming language. Execution is determined by the structure of a graphical block diagram (the LV-source code) on which the programmer connects different function nodes by drawing wires. These wires propagate variables and any node can execute as soon as all its input data become available.

Graphical Programming

LabVIEW ties the creation of user interfaces (called front panels) into the development cycle. LabVIEW programs / subroutines are called Virtual Instruments (VIs). Each VI has three components: a block diagram, a front panel, and a connector panel. The last is used to represent the VI in the block diagrams of other, calling VIs. Controls and indicators on the front panel allow an operator to input data into or extract data from a running virtual instrument. However, the front panel can also serve as a programmatic interface. Thus a Virtual Instrument can either be run as a program, with the front panel serving as a user interface, or, when dropped as a node onto the block diagram, the front panel defines the inputs and outputs for the given node through the connector pane. This implies each VI can be easily tested before being embedded as a subroutine into a larger program.

The graphical approach also allows non-programmers to build programs simply by dragging and dropping virtual representations of lab equipment with which they are already familiar. The LabVIEW programming environment, with the included examples and the documentation, makes it simple to create small applications. [5] •

To maintain clean and legible VI user interfaces keep these tips in mind:

•

Keep panels simple and clean

•

Maintain a consistent style

•

Clean up wires where ever possible

•

Use proper terminology when labeling controls and indicators

\

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2.6


Overview of Stellaris LM 3S8962 Evaluation Board

The LM3S8962 Evaluation Board is a compact and versatile evaluation platform for the Stellaris LM3S8962 ARM® Cortex™-M3-based microcontroller. The Stellaris LM3S8962 Evaluation Kit includes the following features: •

Stellaris LM3S8962 microcontroller with fully-integrated 10/100 embedded Ethernet controller and CAN module

•

Simple setup; USB cable provides serial communication, debugging, and power

•

OLED graphics display with 128 x 96 pixel resolution

•

User LED, navigation switches, and select pushbuttons

•

Magnetic speaker

•

MicroSD card slot

•

USB interface for debugging and power supply

•

Standard ARM® 20-pin JTAG debug connector with input and output modes

•

LM3S8962 I/O available on labeled break-out pads

•

Standalone CAN device board using Stellaris LM3S2110 microcontroller. [5]

Figure 2.3: LM3S8962 Evaluation Board Block Diagram

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2.7


Features of LM3S8962 Micro controller

•

•

32-bit RISC performance using ARM® Cortex™-M3 v7M architecture –

50-MHz operation

–

Hardware-division and single-cycle-multiplication

–

Memory protection unit (MPU), provides a privileged mode for protected

operating system functionality –

Integrated Nested Vectored Interrupt Controller (NVIC)

–

42 interrupt channels with eight priority levels.

•

256-KB single-cycle flash

•

64-KB single-cycle SRAM

•

Four general-purpose 32-bit timers

•

Integrated Ethernet MAC and PHY

•

Controller area network (CAN) module

•

Three fully programmable 16C550-type UARTs

•

Four 10-bit ADC channels (inputs) when used as single-ended inputs

•

One integrated analog comparator

•

One I2C module

•

Two PWM generator blocks –

One 16-bit counter

–

Two comparators

–

Produces two independent PWM signals

–

One dead-band generator

•

Two QEI modules with position integrator for tracking encoder position

•

Two synchronous serial interfaces (SSIs)

•

0 to 42 GPIOs, depending on user configuration

•

On-chip low drop-out (LDO) voltage regulator

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Figure 2.4: ARM Cortex M3 Architecture

2.8

ARM® Cortex™-M3 processor

The ARM® Cortex™-M3 processor has been specifically designed to deliver outstanding performance in cost and power sensitive applications, ranging from complex SoC to low-end microcontrollers.

Based on the ARMv7-M architecture the Cortex-M3 processor is a highly configurable and fully synthesisable processor that includes an efficient Harvard 3-stage pipeline core that delivers more than 1.25 DMIPS/MHz. The core achieves an outstanding power efficiency of 0.047mW/MHz and the standard processor implementation, which includes 32 physical interrupts, achieves 0.06 mW/MHz (0.13µm Metro™ @ 50MHz). To enable the design of cost sensitive devices the Cortex-M3 processor implements tightly coupled system components that reduce processor area and integration issues while significantly improving interrupt handling capabilities and system debug.

Furthermore the central core is up to 30% smaller than existing 3-stage cores, providing additional cost reduction. The Cortex-M3 processor implements the Thumb®-2 ISA to ensure high code density and lower memory requirements. Thumb-2 also provides the exceptional performance expected of a modern 32-bit architecture, while supporting traditional Thumb code. [15] - 13 -


2.8.1


Key Benefits

The ARM Cortex-M3 processor offers significant benefits to system and software developers. •

Lower cost devices through smaller processing core, system and memories

•

Ultra low power consumption and integrated sleep modes

•

Outstanding processing performance for challenging applications

•

Fast interrupt handling for critical control applications

•

Enhanced system debug for faster development

•

No assembler code requirement to ease system development

•

Wide application envelope encompassing ultra-low cost microcontrollers and high performance SoC

Cortex-M3 Processor Applications

The features of the Cortex-M3 processor make it ideal for a wide range of applications, including: •

Cost Sensitive Devices — Generic MCUs, Smart Toys, Personal Electronics

•

Low Power Devices — ZigBee, PAN (Bluetooth), Medical

•

Electronics

•

High Performance Devices — Ultra Low Cost Handsets,

•

Automotive Systems, Mass Storage

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Chapter 3: Project Management 3.1

Requ Requir ired ed Resou esourc rces es

For the project to be made possible, several resources were needed for the research. In order to build the system system for my project, project, understanding understanding the datasheet datasheet of the hardware hardware components components of micro controller, resistor, Capacitor, NPN Darlington Transistor is important. It is so as to make the right approach in the selection of the components.

The resources used throughout the duration of this project are shown below.

3.1. 3.1.1 1 •

Scho Schoo ol Fac Facilit ility y

Library The access to UniSIM library or any neighborhood library is a must. As most of my res researc arch and read read up on the vario ariou us types of appli ppliccatio ation ns for for Microcontrollers, came from the library shelf. Lab view iew books ooks were ere obtai btaine ned d fro from the the libr librar ary y to help help imp improve rove my programming programming skills for for this project. project.

•

Laboratory Free access labs in BLK 82 were open to students of UniSIM every Saturday and and even even Sunda Sunday. y. These These labs labs were were open open as to prov provide ide stude student ntss with with an envir environ onme ment nt were were they they can can do their their testi testing ng and and troub trouble lesh shoo ootin ting g of their their individual project.

3.1. 3.1.2 2

Inte Intern rnet et Br Broa oadb dban and d

The access to internet is very important as most researches could be done by a “click” of the mouse. It is especially essential as many datasheets are available in the World Wide Web for information. The Broadband connection will help speed up the downloading of the information we need.

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Real-Time Signal Analysis with LabView/Micro-processor 3.1. 3.1.3 3


Expe Expend ndit itur uree (COS (COST) T)

In this final year project, some of the components components are funded funded by UniSIM. It is i s rather costly for components like micro controller. Hence, my target is to get the best component and yet minimizing the cost spends on the project.

3.2

Planning

From the start of the project, proper planning is very important important as it contributes the success of the project. Time management factor is the “rule” of having a good graded project. I need to juggle between both my project and my full-time job, having a well plan is not only my own contribution. Project Supervisor, Mr. Qiang Ji, also did his part to meet up and constantly reminding me as not to have lapsed on the planned schedule. [5]

3.3

Cost Cost for for Dev Devel elop opme ment nt

In this section, this is an estimated cost for the entire project. Most components were brought from from

SIM SIM

LIM LIM

Tower ower..

Micr Microo-co cont ntro roll ller er

LM3S LM3S89 8962 62

ARM® ARM®

Cort Cortex ex™-M ™-M33-ba base sed d

microcontroller was provided by the school (UniSIM). S/N 1 2 3 4 5 6 7 8 9 10 11

Description Voltage Regulator – LM7805 +5V Voltage Regulator – LM3940IT +3.3V Temp Sensor – LM35DT/NOPB RESISTOR, METAL FILM, 100KOHM, 1W, 1% CCF60100KFKE36 RESISTOR, METAL FILM, 0.25W, 1%, 5K1 OHM MF1/4CC5101F CAPACITOR ALUM ELECT 0.1UF, 50V, RADIAL CAPACITOR, 10UF, 25V DIODE, STANDARD, 1A, 50V – 1N4001 Darlington Transistor – 2N5308 Axial Fan - 109R0605H402 Power Adapter 240V-12V Total Cost

Unit Price QTY 1 2.00$ 4.17$ 1 2 5.39$ 0.10$ 2 0.49$ 1 2 0.17$ 0.15$ 3 3 0.22$ 0.44$ 1 20.01$ 1 20.00$ 1

Total Cost 2.00$ 4.17$ 10.78$ 0.20$ 0.49$ 0.34$ 0.45$ 0.66$ 0.44$ 20.01$ 20.00$ 59.54$

Table 3.1: Total Cost for Project Above table shown is an estimated cost for the entire project. Under Miscellaneous Items are lists of smaller components include resistors, LEDS, capacitors and soldering iron, etc. The two main costly items are the PIC micro controller and the Axial fan

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3.4


Proj Projec ectt Task Task and and Sch Scheedu dule le

There were slight changes between the planned schedule and the actual dates. Such changes were unavoidable; as there are many other commitments such as assignments, exams, work and unforese unforeseen en circums circumstanc tances es while while develo developing ping the Labvie Labview w design. design. From From the tight tight schedu schedule, le, project plan plan from initial report report is presented presented,, and discrepan discrepancy cy in the the schedules schedules will will be discusse discussed. d. Project tasks are divided into nine sections. 1. Project Consideration and Selection Process 2. Literature Search 3. Preparing for Initial Report (TMA01) 4. Research on project components 5. Design of the simulation model 6. Integration and interaction with LM3S8962 Evaluation board 7. Evaluation and Testing of heat ventilation system 8. Preparing for Final Report (Thesis) 9. Preparing for oral Presentation 

In Task 1, we are allowed to consider the project and need to select the interested project. It takes takes us about 7 days to choose. choose. And the project project committee committee makes allocation allocation for proposed project. It takes about 8 days to approve.



Since Literature research is one of the most important steps for understanding of the project, project, 31 days days are used used for Task 2. 2.



Since preparation of initial report partially depends on Task 2. Task 2 and 3 were carried out at the same time.



We set to complete piratical project work on 1 Aug 2009. The duration for Task 4, 5, 6 and 7 is 175 days. Since the main objective is to develop the automatic heat ventilation system, Task 4 for 29 days, Task 5 for 26 days and Task 6 for 48 days are distributed.



For task 8, preparation for final report is 61 days as it is portrayal of our whole project work and 40% of capstone project score is carried by this task. It will start from 1 Sep 10 and end at submission date 9 Nov 10 and it will also be carried out concurrently with task 7.



For task 9, preparation for oral presentation will start 3 weeks before finish writing of the report. There are 22 days available for this task.

Detailed Project Plan and Gantt chart are attached below.

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Real-Time Signal Analysis with LabView/Microprocessor Duration

Tasks Description

Start Date

End Date

1. Project Consideration and Selection Process

2-Jan-10 2-Jan-10 9-Jan-10

16-Jan-10 8-Jan-10 16-Jan-10

15 7 8

17-Jan-10

16-Feb-10

31

17-Jan-10

30-Jan-10

14

31-Jan-10 17-Feb-10 9-Mar-10 9-Mar-10 21-Mar-10 7-Apr-10 7-Apr-10 16-Apr-10 25-Apr-10

16-Feb-10 8-Mar-10 6-Apr-10 20-Mar-10 6-Apr-10 2-May-10 15-Apr-10 24-Apr-10 2-May-10

17 20 29 12 17 26 9 9 8

3-May-10

19-Jun-10

48

3-May-10 26-May-10 3-Jun-10 20-Jun-10 1-Sep-10 1-Sep-10 8-Sep-10 16-Sep-10 23-Sep-10 15-Oct-10 21-Oct-10 1-Nov-10

25-May-10 2-Jun-10 19-Jun-10 31-Aug-10 31-Oct-10 7-Sep-10 15-Sep-10 22-Sep-10 14-Oct-10 20-Oct-10 31-Oct-10 25-Nov-10

23 8 17 72 61 8 8 8 22 5 10 22

1-Nov-10

15-Nov-10

1.1 Project consideration 1.2 Selection of the project 2. Literature Search 2.1 Research on IEEE online journals , relevant reference books and former student thesis report 2.2 Analyze and study relevant books and journals 3. Preparation of initial report (TMA01) 4. Research on project components 4.1 Research on available temperature sensor 4.2 Design the temperature sensor circuit 5. Design of the simulation model 5.1 Study of existing model 5.2 Create and modify of the model for HV system 5.3 Evaluation of HV system model 6. Integration and interaction with LM3S8962 evaluation board 6.1 Study of existing labview programming 6.2 Programming and evaluate on the model 6.3 Evaluation of design model 7. Evaluation and testing of heat ventilation system 8. Preparation for final report 8.1 Writing skeleton of final report 8.2 Writing Literature search 8.3 Writing Introduction of report 8.4 Writing Main body of report 8.5 Writing conclusion and further study 8.6 Finalizing and amendments of report 9. Preparation for oral presentation 9.1 Review the whole project and decide for presentation

( Days )

12

Resources

Library Resources (Reference Books )

Web Resources (IEEE Journals, Past Thesis, NI website, Related reference Books)

School Lab Facility & Personal computer

LabView software

9.2 Prepare poster for presentation HVAC Control system 16-Nov-10

Table 3.2: Detail Project Plan

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25-Nov-10

10

References

Week

1

Jan 2 3

4

5

Feb 6 7

8

9

Mar 10 11

12

13

Apr 14 15

16

17

May 18 19

20

ACTIVITY

21

Jun 22 23 24 Duration

25

Jul 26 27

28

29

Aug 30 31

32

33

Sep 34 35

36

37

Oct 38 39

40

41

Nov 42 43

1. Project Consideration and Selection 2. Literature Search 2.1 Find relevant reference books and IEEE online journals 2.2 Review and study relevant books and journals 3. Preparation of Initial Report (TMA01) 4. Research on project components 4.1

Research on available temperature sensor

4.2 Design the temperature sensor circuit 5. Design of the simulation model 5.1 Study existing model 5.2 Create and modify the model for HV system 5.3 Evaluation of HV system model 6. Integration and interaction with LM3s8962 evaluation board 6.1 Study of existing labview programming 6.2 Programming and evaluate on the model 6.3 Evaluation of the design model 7. Evaluation and testing of heat ventilation system 8. Preparation of Final Report 8.1 Writing skeleton of final report 8.2 Writing Literature review 8.3 Writing Introduction of reort 8.4 Writing Main Body of report 8.5 Writing Conclusion and Further study 8.6 Finalizing and Amendments of reort 9. Preparation of oral presentation 9.1 Review and extract important notes for presentation 9.2 Create poster and prepare for presentation Main Task Legend

Actual

Sub Task

Figure 3.1: Gantt chart

- 19 -

Chapter 4: Overall System Design 0In order to simulate the Automatic Heat Ventilation system, a small system model was built using the small container. There consist of Internal Sensor board, Power Supply and External sensor board and Micro-controller board. In order to ventilate the air, the small holes are drilled at the side of the container. A light Bulb is used as the heat source to provide to the system.

44

Chapter 4: Overall System Design 0In order to simulate the Automatic Heat Ventilation system, a small system model was built using the small container. There consist of Internal Sensor board, Power Supply and External sensor board and Micro-controller board. In order to ventilate the air, the small holes are drilled at the side of the container. A light Bulb is used as the heat source to provide to the system.

Figure 4.1: System Block Diagram

A 12V dc adapter is continuously supplied to the system. When the system is powered up, internal sensor and external sensors are kept measuring of the temperature inside the container and outside temperature. And the light was turned ON to generate the heat source. When the temperature difference between internal and external reaches to 5 Degree, the fan was started to turn on to ventilate the air and let the internal room temperature to be comfortable temperature. User can monitor the temperature on the display by the choice of Degree Fahrenheit and Celsius.

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Chapter 5: Hardware Design and Specification The system model is comprised of Internal sensor Board (ISB), External sensor board (ESB) and LM 3S8962 Evaluation Board and the cooling Fan. Usually for microcontroller, the development kits are available together with an evaluation board or some hardware foundation, from which we can build our system. For LM368962 micro-controller, a demonstration board is available. The demonstration board was studied in details so as design the hardware.

5.1

Stellaris LM 3S8962 Evaluation Board

The Stellaris LM3S8962 Evaluation Board is a compact and versatile evaluation platform for the Stellaris LM3S8962 ARM Cortex TM-M3-based microcontroller. The evaluation kit design highlights the LM3S8962 micro-controller’s integrated CAN and 10/100 Ethernet controllers. As well as implementing an embedded web server, the kit functions as a complete controller area network (CAN) by providing two boards each with a Stellaris microcontroller.

The main evaluation board (EVB) is the CAN host. A small CAN device board, linked with ribbon cable, uses a Stellaris LM 32S2110 microcontroller. The function of each board is fully configurable in software. The EVB can be used as an evaluation platform or as low-cost incircuit debug interface (ICDI)

In debug interface mode, the on-board microcontroller is bypassed, allowing connection of the debug signals to an external Stellaris microcontroller target. The kit is also compatible with high-performance external JTAG debuggers.

The evaluation kit enables quick evaluation, prototype development and creation of application-specific designs for Ethernet and CAN networks. The kit also includes extensive source-code examples, allowing the user to start building C code applications quickly. [1]

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Figure 5.1: Stellaris LM3S8962 Evaluation Board Layout

The Stellaris LM3S8962 evaluation board includes a range of useful peripherals and an integrated in circuit debug interface (ICDI). The main features that includes in evaluation board are 1. LM3S8962 Microcontroller 2. Ethernet 3. CAN module 4. Clocking 5. Reset 6. Power Supplies 7. Debugging 8. Debugging Modes

In this project, we do not need to configure specially for Microcontroller, Clocking, Reset and Power Supplies. It can be used from the evaluation kit.

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5.1.1


LM3S8962 Microcontroller

The heart of the EVB is a Stellaris LM3s8962 ARM Cortex-M3-based microcontroller. The LM3S8962 offers 256-KB flash memory, 50-MHz operation, an Ethernet controller, a CAN module and wide range peripherals. [1]

5.1.2

Clocking

The LM3S8962 microcontroller has four on-chip oscillators; three are implemented on the EVB. An internal 12 MHz oscillator is the clock source the microcontroller uses during and following POR. An 8.0-MHz crystal completes the LM3S8962’s main internal clock circuit. An internal PLL, configured in software, multiplies this clock to 50-MHz for core and peripheral timing. The internal 12 MHz oscillator is the primary clock source during start-up.

A small, 25-MHz crystal is used by the LM3S8962 microcontroller for Ethernet physical layer timing.

5.1.3

Reset

The LM3S8962 microcontroller shares its external reset is input with OLED display. External reset is asserted (active low) under any one of the three conditions. •

Power-on reset

•

Reset push switch SW1 held down

•

Internal debug mode- By the USB device controller (U4 FT2232) when instructed by debugger.

5.1.4

Power Supplies

The LM3S8962 is powered from a +3.3-V supply. A low drop-out (LDO) regulator regulates +5V power from the USV cable to +3.3-V. +3.3-V power is available for powering external circuits. A +15-V rail is available when the OLED display power supply is active. The speaker and the OLED display boost-converter operate from the +5-V rail.

5.2

External Sensor Board

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External sensor board (ESB) consists of two voltage regulator, External sensor, Resistor, Capacitor, on/off switch that can be powered from a wall adapter, Darlington transistor and Diode.

Figure 5.2: Schematic for external sensor board.

The input voltage from 12-V adapter is reduced down by the voltage regulator LM7805 and the voltage is supplied to the internal and external sensor. After that output voltage is crossed to the LM3940 voltage regulator and gives the output around 3.3-V.

Darlington transistors are used as electronic switches in this project. In a grounded-emitter transistor circuit, such as the light-switch circuit shown, as the base voltage raises the base and collector current rise exponentially.

If VCE could fall to 0 (perfect closed switch) then Ic could go no higher than VCC / RC, even with higher base voltage and current. The transistor is then said to be saturated. Hence, values of input voltage can be chosen such that the output is either completely off. Therefore the transistor is acting as a switch. 5.2.1 Voltage Regulator

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A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. It may use an electromechanical mechanism, or passive or active electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.

With the exception of passive shunt regulators, all modern electronic voltage regulators operate by comparing the actual output voltage to some internal fixed reference voltage. Any difference is amplified and used to control the regulation element in such a way as to reduce the voltage error. This forms a negative feedback control loop; increasing the open-loop gain tends to increase regulation accuracy but reduce stability (avoidance of oscillation, or ringing during step changes). There will also be a trade-off between stability and the speed of the response to changes. If the output voltage is too low (perhaps due to input voltage reducing or load current increasing), the regulation element is commanded, up to a point, to produce a higher output voltage - by dropping less of the input voltage (for linear series regulators and buck switching regulators), or to draw input current for longer periods (boost-type switching regulators); if the output voltage is too high, the regulation element will normally be commanded to produce a lower voltage. However, many regulators have over-current protection; so that they will entirely stop sourcing current (or limit the current in some way) if the output current is too high, and some regulators may also shut down if the input voltage is outside a given range.

Figure 5.3: Voltage regulator symbol

5.2.2

Measures of regulator quality

The output voltage can only be held roughly constant; the regulation is specified by two measurements: Load regulation is the change in output voltage for a given change in load current (for example: "typically 15mV, maximum 100mV for load currents between 5mA and 1.4A, at some specified temperature and input voltage").

- 25 -



line regulation or input regulation is the degree to which output voltage changes with input (supply) voltage changes - as a ratio of output to input change (for example "typically 13mV/V"), or the output voltage change over the entire specified input voltage range (for example "plus or minus 2% for input voltages between 90V and 260V, 50-60Hz").

Figure 5.4: Schematic for checking regulator quality

5.2.3

LM35 - Precision Centigrade Temperature Sensor

The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling.

The LM35 does not require any external calibration or trimming to provide typical accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C temperature range. Low cost is assured by trimming and calibration at the wafer level.

The LM35’s low output impedance, linear output, and precise inherent calibration make interfacing to readout or control circuitry especially easy. It can be used with single power supplies, or with plus and minus supplies. As it draws only 60 μA from its supply, it has very low self-heating, less than 0.1°C in still air.

The LM35 is rated to operate over a −55° to +150°C temperature range,while the LM35C is rated for a −40° to +110°C range (−10°with improved accuracy). The LM35 series is available packaged in hermetic TO-46 transistor packages, while the LM35C, LM35CA, and LM35D are

- 26 -



also available in the plastic TO-92 transistor package. The LM35D is also available in an 8lead surface mount small outline package and a plastic TO-220 package.

Table 5.1: LM35 Sensor Feature

Figure 5.5: Temperature sensor configuration

- 27 -


5.2.4


Ohm's law

The behavior of an ideal resistor is dictated by the relationship specified in Ohm's law:Ohm's law states that the voltage (V) across a resistor is proportional to the current (I) through it where the constant of proportionality is the resistance (R). Equivalently, Ohm's law can be stated: This formulation of Ohm's law states that, when a voltage (V) is maintained across a resistance (R), a current (I) will flow through the resistance. [10]

5.2.5

Four-band resistors

Four-band identification is the most commonly used color-coding scheme on resistors. It consists of four colored bands that are painted around the body of the resistor. The first two bands encode the first two significant digits of the resistance value, the third is a power-of-ten

- 28 -



multiplier or number-of-zeroes, and the fourth is the tolerance accuracy, or acceptable error, of the value. The first three bands are equally spaced along the resistor; the spacing to the fourth band is wider. Sometimes a fifth band identifies the thermal coefficient, but this must be distinguished from the true 5-color system, with 3 significant digits.

For example, green-blue-yellow-red is 56×104 Ω = 560 kΩ ± 2%. An easier description can be as followed: the first band, green, has a value of 5 and the second band, blue, has a value of 6, and is counted as 56. The third band, yellow, has a value of 104, which adds four 0's to the end, creating 560,000 Ω at ±2% tolerance accuracy. 560,000 Ω changes to 560 kΩ ±2% (as a kilo- is 103). Each color corresponds to a certain digit, progressing from darker to lighter colors, as shown in the chart below. [10]

Table 5.2: Resistor-band configuration

5.2.6

Capacitor

A capacitor (formerly known as condenser) is a passive electronic component consisting of a pair of conductors separated by a dielectric (insulator). When there is a potential difference (voltage) across the conductors a static electric field develops in the dielectric that stores energy and produces a mechanical force between the conductors. An ideal capacitor is

- 29 -



characterized by a single constant value, capacitance, measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them.

A capacitor is assumed to be self-contained and isolated, with no net electric charge and no influence from any external electric field. The conductors thus hold equal and opposite charges on their facing surfaces, and the dielectric develops an electric field. In SI units, a capacitance of one farad means that one coulomb of charge on each conductor causes a voltage of one volt across the device.

The capacitor is a reasonably general model for electric fields within electric circuits. An ideal capacitor is wholly characterized by a constant capacitance C, defined as the ratio of charge ±Q on each conductor to the voltage V between them. Sometimes charge build-up affects the capacitor mechanically, causing its capacitance to vary. In this case, capacitance is defined in terms of incremental changes. [11]

Figure 5.6: Capacitor configuration

5.2.7

Diode

A diode is a two-terminal electronic component that conducts electric current in only one direction. The term usually refers to a semiconductor diode, the most common type today. This is a crystalline piece of semiconductor material connected to two electrical terminals. [1] A vacuum tube diode (now little used except in some high-power technologies) is a vacuum tube with two electrodes: a plate and a cathode.

- 30 -



The most common function of a diode is to allow an electric current to pass in one direction (called the diode's forward direction) while blocking current in the opposite direction (the reverse direction). Thus, the diode can be thought of as an electronic version of a check valve. This unidirectional behavior is called rectification, and is used to convert alternating current to direct current, and to extract modulation from radio signals in radio receivers.

However, diodes can have more complicated behavior than this simple on-off action, due to their complex non-linear electrical characteristics, which can be tailored by varying the construction of their P-N junction. These are exploited in special purpose diodes that perform many different functions. For example, specialized diodes are used to regulate voltage (Zener diodes), to electronically tune radio and TV receivers (varactor diodes), to generate radio frequency oscillations (tunnel diodes), and to produce light (light emitting diodes).

Features

Table 5.3: Diode Features

Figure 5.7: Diode specification - 31 -



- 32 -

Real-Time Signal Analysis with LabView/Micro-processor 5.2.8


Darlington transistor

Darlington transistor (often called a Darlington pair) is a compound structure consisting of two bipolar transistors (either integrated or separated devices) connected in such a way that the current amplified by the first transistor is amplified further by the second one. This configuration gives a much higher current gain (written β, hfe, or hFE) than each transistor taken separately and, in the case of integrated devices, can take less space than two individual transistors because they can use a shared collector. Integrated Darlington pairs come packaged singly in transistor-like packages or as an array of devices (usually eight) in an integrated circuit. [16]

Figure 5.8: Darlington transistor symbol

Figure 5.9: Darlington transistor configuration

This device is designed for applications requiring extremely high current gain at currents to 1.0A.

- 33 -



- 34 -



5.3 Internal Sensor Board The input voltage to internal sensor is supplied by external sensor board via J7 connector. And the output voltage of the temperature sensor is connected via J8 connector to the ADC input of the micro-controller.

Figure 5.10: Internal Sensor board

- 35 -



Chapter 6: Software Development LabVIEW

(Laboratory

Virtual

Instrument Engineering Workbench) is a graphical

programming language that uses icons instead of lines of text to create applications. In contrast to text-based programming languages, where instructions determine the order of program execution, LabVIEW uses dataflow programming where the flow of data through the nodes on the block diagram determines the execution order of the VIs and functions. VIs or virtual instruments are LabVIEW programs that imitate physical instruments. Each VI has three components: a block diagram, a front panel, and a connector panel.

In LabVIEW, a user interface is built by using a set of tools and objects. The user interface is known as the front panel. The codes are added using graphical representations of functions to control the front panel objects. This graphical user source code is also known as G code or block diagram code. The block diagram contains this code. In some ways the block diagram resembles a flowchart.

In this project, 7 VIs are constructed to monitor the temperature in different forms. 1. Conversion Degree Celsius to Fahrenheit 2. Internal Thermometer 3. External Thermometer 4. Internal Temperature Monitor 5. External Temperature Monitor 6. Internal and External Temperature Monitor 7. Fan out

6.1

Conversion of Degree Celsius to Fahrenheit

Figure 6.1: Block diagram of conversion

- 36 -



In order to display the user’s choice of the Degree Celsius and Fahrenheit, block diagram for conversion VI is constructed as in Figure 5.1. Degree Fahrenheit is converted by using the formula [ ° F ] = [ °C ] ×

9 5

+ 32 .

This VI will be used in another VI as a selection of Celsius or

Fahrenheit.

As a user interface (the front panel) will be shown as in below figure.

Figure 6.2: Front panel of conversion

6.2

Internal Thermometer

Figure 6.3: Internal Thermometer.

Internal temperature sensor is connected via Analogue to Digital Converter pin (ADC1) of Micro-controller. As the temperature sensor (LM35) gives the changes of 10mV per degree Celsius, the output of the sensor is multiplied by 100 to get the temperature reading. Conversion of Temperature VI is embedded into it for the user to select in terms of Degree Celsius or Degree Fahrenheit. And the temperature is displayed on the thermometer and value as a user interface.

- 37 -


6.3


External Thermometer As the same as the internal temperature sensor, external temperature sensor is

connected to Analogue to Digital Converter (ADC3). The outside temperature can be monitored in terms of Thermometer or value. The block diagram for External temperature is as shown in below figure.

Figure 6.4: Block diagram of External Thermometer

6.4

Internal Temperature Monitor

In order to see visually on the chart, the internal thermometer VI is embedded into Internal Temperature Monitor. From the chart, the user can be monitored the temperature in terms of Degree Celsius or Fahrenheit.

Figure 6.5: Block diagram of Internal Temperature Monitor

6.5

External Temperature Monitor

With the help of external thermometer VI, the external temperature chart can be monitored by building the below block diagram.

- 38 -



Figure 6.6: Block diagram of External Temperature Monitor

6.6

Internal and External Temperature Monitor

In order to monitor the internal and external temperature at the same time, the block diagram is constructed as shown in below figure.

Figure 6.7: Block diagram of Internal and External Temperature - 39 -


6.7


Fan Out

For simulation purpose, after switched on the supply, the internal temperature and external temperature are kept measuring the surrounding temperature. And then the light bulb is turned on to generate as a heat source. After difference of internal and external temperature reaches to 5 Degree, the micro-controller gives the output voltage to output pin PC7. The temperature monitoring charts are used to know the temperature difference. The flow is designed by using below block diagram.

Figure 6.8: Block diagram of Fan out

- 40 -



Chapter 7: Integration and Testing Before the hardware and software are integrated as a system, it needs to be tested out in order to prevent for unforeseen failure. In this project, the individual and Combine of software and hardware are tested out as follows

•

LM3S8962 Evaluation board Testing

•

Hardware Testing

•

Software Testing

7.1

LM3S8962 Evaluation board Testing

In order to test the evaluation board functional status, we created the blinking Led on the LM3S8962 Evaluation board. The steps of building the VI are carried out and monitor the rate of the blinking LED by adjusting the delay (ms) function in the Block Diagram

The VI was constructed by following blocks.



Elemental I/O > Digital Output > LED0.



Programming > Express > Execution Control > While Loop



Add Shift Register



Programming >Boolean > Not and False Constant.



Wire up the functions after placing the functions



Programming > Time, Dialog & Error > Wait (ms).



Programming > Numeric > Numeric Constant.

The finished Front Panel and Block Diagram will look like in below figure.

- 41 -



Figure 7.1: Final Front-panel for blinking LED VI

Figure 7.2: Final Block Diagram for blinking LED VI

It needs to ensure that the “ Enable Debugging” check box is selected and under Debug options that it is selected to “Run on target using ULINK2” at EK-LM3S8962 Build Specification.

- 42 -



Figure 7.3: Setting Build Specification After running the VI, You will observe that the LED on the hardware itself is blinking. The rate of the blinking is due to the Wait (ms) function in the Block Diagram. You can stop the VI, change the value and run again. Click Stop button when you want to stop the VI.

Or press reset button on the EK-LM3S8962 board.

Figure 7.4: Blinking of LED on Evaluation board From the above test, we can conclude that EK-LM3S8962 Evaluation board is functionally working. - 43 -


7.2


Hardware Testing

A voltage regulator generates a fixed output voltage of a preset magnitude that remains constant regardless of changes to its input voltage or load conditions. In this project, we only need 5V to automatically maintain a constant voltage level for fan, temperature sensor and respective capacitor and resistor.

In the first phase we need to check the incoming voltage when the power on status. It must be DC voltage around 12V.

Figure 7.5: Testing on incoming voltage

After the current goes through the regulator, it will step down incoming 12 V to 5V.

Figure 7.6: Output Voltage after LM7805

- 44 -



After the current goes through the second regulator, expected voltage is around 3V as the stand-by supply for the micro-controller. .

Figure 7.7: Output Voltage after LM3940

After the output voltage testing is confirmed, the supply to the temperature is applied and tested the output voltage of the external temperature sensor. As the temperature is calibrated to 10mV per 1 degree Celsius, the output of the temperature is measured about 291mV as shown in below figure.

Figure 7.8: Output Voltage of External/Outside Temperature sensor

- 45 -



The internal heat source is applied by using 12 V and the output of the internal temperature is measured as follow figure.

Figure 7.9: Output Voltage of Internal Temperature sensor

- 46 -


7.3


Software Testing

The VI constructed in the process of Software development are tested by integrating with the hardware.

7.3.1

Internal Thermometer

After running the block diagram, we can monitor the internal temperature as thermometer and temperature value. Depend on the choice of user; the temperature can be toggled as Degree Fahrenheit or Degree Celsius. The front panel screen can be seen as follows.

Figure 7.10: Internal Thermometer 7.3.2

External Thermometer

The external thermometer is constructed as the same flow with the internal thermometer. The outside temperature sensor that connected through the ADC pin of the microcontroller is monitored by using the following front panel.

- 47 -



Figure 7.11: External Thermometer 7.3.3

Internal Temperature Monitor

In order to know the fluctuation of the temperature, the history of the temperature can be monitored on the Internal Temp History chart. From the front-panel, user can monitor the temperature in terms of Degree Fahrenheit or Celsius as shown in below figures.

Figure 7.12: Internal Temperature History in Fahrenheit

- 48 -



After toggling the Temp Scale, the temperature changes from around 85 Degree Fahrenheit to around 31 Degree Celsius.

Figure 7.13: Internal Temperature History in Celsius

7.3.4

External Temperature Monitor

From the user interface of the front-panel, the history of the external temperature can be monitored in terms of Degree Fahrenheit or Celsius. By defining the time interval in Labview VI, the history of the temperature is monitored as followed.

Figure 7.14: External Temperature History in Fahrenheit

- 49 -



Figure 7.15: External Temperature History in Celsius

7.3.5

Internal and External Temperature Monitor

For the convenience of user, VI for monitoring the external temperature and internal temperature is constructed and can be observed from below figures.

Figure 7.16: Internal temperature monitor

- 50 -



Figure 7.17: External temperature monitor

The history of the temperature and the current temperature can be examined in terms of Fahrenheit or Celsius.

- 51 -



Chapter 8: Simulation and Result After testing and verification of individual components, the final system was built up and the reliability of the system is tested. The system is powered up and tested by using the Labview program and monitored the temperature from the front panel. The temperature is around 32 degree Celsius for inside and outside of the system model. The temperature is as shown in below figure.

Figure 8.1: Temperature history of inside and outside of the system model

To monitor the basic of the HVAC system, a 12 V 10W light bulb is used as a heat source and monitored the temperature. Before the light bulb is turned on, the difference between internal and external temperature is set to 5 degree Celsius.

After the heat source is ON, the temperature is increased gradually and the fan will not turned on until it reaches to 5 degree difference. When the voltage difference reaches to around 4.9 degree, the fan is started to move according to the hardware design using the Darlington transistor. The temperature history difference can be seen as shown in below figure.

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Figure 8.2: The temperature difference after heat source is ON

When the internal temperature is reached to 5 degree difference, the fan ventilation is initiated. By adjusting the temperature difference, it can be reduced to temperature. The minimum temperature difference that can go down during the heat source is ON is around 3 degree Celsius. That makes the things inside of the system model to stay at comfortable temperature. It was observed that time taken to reach to comfortable temperature is about 7 minutes.

Figure 8.3: The minimum temperature difference

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Once the heat source is turned off the interior temperature drops from 35 degree Celsius to 32 degree Celsius in 2 minutes and the fan is automatically deactivated. Since the interior temperature already matches the exterior temperature, ventilation is not required anymore. That gives the energy saving.

The next experiment is to turn on again the internal heat source, once the interior temperature rise more than 2 degree Celsius difference. And then the fan start to activate and prevent the interior further rising , the interior temperature is maintain around 33 degree Celsius after two minutes with this the heat ventilation system maintain the minimum possible interior temperature as the set point temperature is determine by the exterior temperature and adapt accordingly to the environment temperature changes.

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Chapter 9: Problem Encountered As inexperienced to circuit design, a lot of problems were encountered for choosing components at initial stage. With all engineering design, there may be challenges that cannot be foreseen during the design stage and discover along with the implementation.

9.1

Choice of temperature sensor

At the beginning of design stage, I am not sure which type of temperature sensor to use. There are different types of temperature sensor available in the market. Firstly, designing of Op-Amp with temperature is considered. But it is not matched to input voltage of the controller.

Solution The ADC of Micro-controller is 10 bit ADC and the data sheet for Analog to Digital Input Voltage is as follow.

VADCIN

Maximum single-ended, full-scale an analog input voltage Minimum single-ended, full-scale analog input voltage Maximum differential, full-scale an analog input voltage Minimum differential, full-scale analog input voltage

3.0V 0.0V 1.5V 0.0V

Table 9.1: the ADC input Voltage The LM 35 Centigrade temperature was chosen to use in this project. 10 bit ADC = 210 = 1024 For Single-ended input, the minimum resolution =

3 1024

= 3 mV .

And the output of the sensor is 10 mV per degree. So 0.3 degree will be changed in every 3 mV. For Differential input, the minimum resolution =

1.5 1024

= 1.5 mV .

And the output of the sensor is 10 mV per degree. So 0.15 degree will be changed in every 1.5 mV. From above calculation, we can conclude that we do not need the Op-amp because 0.3 degree in temperature change is good enough to provide the good accuracy.

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9.2


Choice of Light bulb.

At first, Light Bulb (12V 100W) is planned to use as a heat source. The supply of the circuit is provided by 12 V DC and 1.5 A (3 pin Adapter). After taking quite a long time, a bit of reddish on the filament was seen.

Solution By calculating the current for the light bulb, it gives that P = VI

⇒ I =

P

=

100 12

V

= 8.3 A . That is far

away from what the current of the adapter can be supplied So by calculating the power that the adapter can be supplied, it gives that P = VI = 12 × 1.5 = 18 W .

Therefore, the light bulb which has 12 V 10W was chosen as a heat source.

9.3

Connection on the Darlington transistor

After prototyping was done on the board, the output voltage of the fan is tested and gives 0V. Solution The circuit was connected as in below diagram.

R2 J5 Darlington Transistor

J4 D3

Figure 9.1: Wrong Connection circuit for fan output When the transistor turns on, it pulls down the output voltage of the collector to zero voltage. After verifying the circuit and connected as below, it can be measured for output voltage for fan.

R2 J5 Darlington Transistor

5V D3

J6

J4

Figure 9.2: Corrected circuit for fan output

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Chapter 10: Conclusion and Recommendation 10.1 Conclusion The automatic heat ventilation system based on natural environment cooling concept was built, tested and demonstrated using LabView. The system works effectively in real time and the natural environment cooling concept ensure that the heat ventilation system maintain the minimum possible temperature as the set point temperature is determine by the exterior environment temperature. The ventilation is deactivated when the interior temperature drops to comfortable temperature thus allow energy saving for unnecessary ventilation.

This project is actually successfully done with significant control, time and budget. The project can be implemented very much close the plan without much deviation. All the problems and difficulties can be overcome even though it has been very tedious and stressful to identify the root causes of the problems.

The project reflects all aspects of Proper Hardware and Software Design as well as the efficient troubleshooting and effective management still.

10.2 Future recommendations In the modern world, most of the parents are out of the house with leaving children with maid or grandparents. If the maid or grandparents overslept and the kitchen oven overheats or children room temperature getting higher, parent can use the internet to control, adjust the temperature and alarm the respective person at home.

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Chapter 11: Critical Review and Reflection 11.1 Review and Reflections I have faced through several problems in the entire project. From the initial start of the project, I knew it would not be easy beacause I have little knowledge of the lab view and micro controller. However upon completion of the project, I was able to better understand my strengths and weakness.

In this Final Year Project (FYP), UniSIM had given me the opportunity to realize my strengths. I started by running simple sample programs and slowly edit and research in further developing what was needed to fulfill the project. I am able to source for solutions once I have encounter problems in the project. In the other hand, Project supervisor Qian Ji gave me a numerous advice and guide through in whole project.

My weakness would be the development of software and hardware integration. I believe that my understanding of the microcontroller wasn’t in depth enough. The problem came when there is a delay as the hardware integration seems to have a problem. However, after doing some researches and read up, I manage to complete the project. Throughout this entire project, I must admit there are times of giving up but with the determination and encouragement from tutor and friends, I have managed to pull through and complete the project in the given time frame.

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11.2 Skills Review

For this project, a great deal of knowledge of both software and hardware is required to make it possible. Skills like project management and information researches are greatly enhanced over the period of the entire project.

I would say Project management skill is the most important in making the project a successful one. The tight schedule of juggling both part time studies and a full time job makes it difficult. These were overcome as proper planning was carried out. From the beginning lots of researches were done over the internet, regional library to know more about embedded systems. Lots of time were spend on Project Overview and Literature Review as of knowing what was already available in the market, as to make this project both cost effective and workable.

Troubleshooting skills are also required for this project which I have obtained the skills from the ENG301 Mircroprocessor programming (labview), PMJ300-Project Management skills will also be used in creating the software interface for the system to work. Database and System Analysis and Design skills are also used in this project.

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References [1]

LabVIEW Programming, Data Acquisition and Analysis (with CD-ROM) Jeffrey Y. Beyon

[2]

Engineering Circuit Analysis, 7th Edition

[3]

Principles of Electronic Materials and Devices ( Third Edition ) by S.O.Kasap

[4]

The Definitive Guide to the ARM Cortex-M3 by Joseph Yiu

[5]

ENG 301 –Microprocessor Programming

[6]

PMJ 300- Project Management

[7]

Applied Electromagnetism and Materials André Moliton

[8]

M. James,” Microcontroller cookbook”, Published 2001 by Oxford Newnes

[9]

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

[10]

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

[11]

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

[12]

http://www.farnell.com

[13]

http://chrisgammell.com/2008/12/16/circuit-board-design-and-how-it-haschanged/

[14]

http://www.ni.com/arm

[15]

http://www.arm.com

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APPENDIXES 1. LM35 - Precision Centigrade Temperature Sensor Electrical Characteristics

Note 1: Unless otherwise noted, these specifications apply: −55°C£TJ£+150°C for the LM35 and LM35A; −40°£TJ£+110°C for the LM35C and LM35CA; and 0°£TJ£+100°C for the LM35D. VS=+5Vdc and ILOAD=50 μA, in the circuit of Figure 2. These specifications also apply from +2°C to TMAX in the circuit of Figure 1. Specifications in boldface apply over the full rated temperature range.

Note 2: Thermal resistance of the TO-46 package is 400°C/W, junction to ambient, and 24°C/W junction to case. Thermal resistance of the TO-92 package is 180°C/W junction to ambient. Thermal resistance of the small outline molded package is 220°C/W junction to ambient. Thermal resistance of the TO-220 package is 90°C/W junction to ambient. For additional thermal resistance information see table in the Applications section.

Note 3: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output due to heating effects can be computed by multiplying the internal dissipation by the thermal resistance.

Note 4: Tested Limits are guaranteed and 100% tested in production.

Note 5: Design Limits are guaranteed (but not 100% production tested) over the indicated temperature and supply voltage ranges. These limits are not used to calculate outgoing quality levels.

Note 6: Specifications in boldface apply over the full rated temperature range.

Note 7: Accuracy is defined as the error between the output voltage and 10mv/°C times the device’s case temperature, at specified conditions of voltage, current, and temperature (expressed in °C).

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Note 8: Nonlinearity is defined as the deviation of the output-voltage-versus-temperature curve from the best-fit straight line, over the device’s rated temperature range.

Note 9: Quiescent current is defined in the circuit of Figure 1.

Note 10: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating

2. Tools Palette of Labview

1. The Tools palette is available on the front panel and the block diagram.A tool is a special operating mode of the mouse cursor. The cursorcorresponds to the icon of the tool you select on the palette.

2. Use the toolsto operate and modify front panel and block diagram objects.

3. If automatic tool selection is enabled and you move the cursor over objects on the front panel or block diagram, LabVIEW automatically selects the corresponding tool from the Tools palette.Select View»Tools Palette to display the Tools palette. LabVIEW retains the Tools palette position so when you restart LabVIEW, the palette appears in the same position.

Tip Press the key and right-click to display a temporary version of the Tools palette at

the location of the cursor.

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3. Nodes of Labview

Nodes are objects on the block diagram that have inputs and/or outputs and perform operations when a VI runs. They are analogous to statements,operators, functions, and subroutines in text based programming languages. The Add and Subtract functions in the previous figure are

4.Wires of Labview

You transfer data among block diagram objects through wires. In the previous figure, wires connect the control and indicator terminals to the Add and Subtract functions. Each wire has a single data source, but you can wire it to many VIs and functions that read the data. Wires are different colors, styles, and thicknesses, depending on their data types. A broken wire appears as a dashed black line with a red X in the middle. Broken wiresoccur for a variety of reasons, such as when you try to wire two objects with incompatible data types.

5. LM3S8962 Evaluation Kit Target Applications

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KyawThuYaThein FYP

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