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 2010

Real-Time Signal Analysis with Kyaw Thu Ya Thein (H0705065)LabView/Micro-processor

ACKNOWLEDGEMENTS Firstly, I would like to express my sincere and heartfelt appreciation to my project 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 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.

Throughout my thesis-writing period, he provided encouragement, sound advice, 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 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 system are installed and assembled inside some 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 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 cost, with user-friendly interface, with less complexity and with effective 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

1.3 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

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..............................................................................................24

5.2.1 Voltage Regulator............................................................................................25

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

7.3 Software Testing......................................................................................................47

7.3.1 Internal Thermometer.......................................................................................47

7.3.2 External Thermometer......................................................................................47

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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

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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1.3 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

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hot water 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

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converted 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 low-

temperature 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 (N2)

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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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]

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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 Required Resources

For the project to be made possible, several resources were needed for the research. In order

to build the system for my project, understanding the datasheet of the hardware 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.

3.1.1 School Facility

Library

The access to UniSIM library or any neighborhood library is a must. As most

of my research and read up on the various types of applications for

Microcontrollers, came from the library shelf.

Lab view books were obtained from the library to help improve my

programming skills for this project.

Laboratory

Free access labs in BLK 82 were open to students of UniSIM every Saturday

and even Sunday. These labs were open as to provide students with an

environment were they can do their testing and troubleshooting of their

individual project.

3.1.2 Internet Broadband

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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3.1.3 Expenditure (COST)

In this final year project, some of the components are funded by UniSIM. It is 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 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 for Development

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

from SIM LIM Tower. Micro-controller LM3S8962 ARM® Cortex™-M3-based

microcontroller was provided by the school (UniSIM).

S/N Description Unit Price QTY Total Cost1 Voltage Regulator – LM7805 +5V 2.00$ 1 2.00$2 Voltage Regulator – LM3940IT +3.3V 4.17$ 1 4.17$3 Temp Sensor – LM35DT/NOPB 5.39$ 2 10.78$4 RESISTOR, METAL FILM, 100KOHM, 1W, 1% CCF60100KFKE36 0.10$ 2 0.20$5 RESISTOR, METAL FILM, 0.25W, 1%, 5K1 OHM MF1/4CC5101F 0.49$ 1 0.49$6 CAPACITOR ALUM ELECT 0.1UF, 50V, RADIAL 0.17$ 2 0.34$7 CAPACITOR, 10UF, 25V 0.15$ 3 0.45$8 DIODE, STANDARD, 1A, 50V – 1N4001 0.22$ 3 0.66$9 Darlington Transistor – 2N5308 0.44$ 1 0.44$

10 Axial Fan - 109R0605H402 20.01$ 1 20.01$11 Power Adapter 240V-12V 20.00$ 1 20.00$

Total Cost 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

- 16 -


3.4 Project Task and Schedule

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 unforeseen circumstances while developing the Labview design. From the tight schedule,

project plan from initial report is presented, and discrepancy in the schedules will be

discussed.

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 us about 7 days to choose. And the project committee makes

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, 31 days are used for Task 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.

- 17 -


Detailed Project Plan and Gantt chart are attached below.

Real-Time Signal Analysis with LabView/Microprocessor

Tasks Description Start Date End DateDuration

( Days )Resources

1. Project Consideration and Selection Process 2-Jan-10 16-Jan-10 15Library

Resources

(Reference

Books )

Web Resources

(IEEE Journals,

Past Thesis,

NI website,

Related

reference

Books)

School Lab

Facility &

Personal

computer

LabView

software

HVAC Control

system

References

1.1 Project consideration 2-Jan-10 8-Jan-10 7

1.2 Selection of the project 9-Jan-10 16-Jan-10 8

2. Literature Search 17-Jan-10 16-Feb-10 31

2.1 Research on IEEE online journals , relevant

reference books and former student thesis report17-Jan-10 30-Jan-10 14

2.2 Analyze and study relevant books and journals 31-Jan-10 16-Feb-10 17

3. Preparation of initial report (TMA01) 17-Feb-10 8-Mar-10 20

4. Research on project components 9-Mar-10 6-Apr-10 29

4.1 Research on available temperature sensor 9-Mar-10 20-Mar-10 12

4.2 Design the temperature sensor circuit 21-Mar-10 6-Apr-10 17

5. Design of the simulation model 7-Apr-10 2-May-10 26

5.1 Study of existing model 7-Apr-10 15-Apr-10 9

5.2 Create and modify of the model for HV system 16-Apr-10 24-Apr-10 9

5.3 Evaluation of HV system model 25-Apr-10 2-May-10 8

6. Integration and interaction with LM3S8962 evaluation

board3-May-10 19-Jun-10 48

6.1 Study of existing labview programming 3-May-10 25-May-10 23

6.2 Programming and evaluate on the model 26-May-10 2-Jun-10 8

6.3 Evaluation of design model 3-Jun-10 19-Jun-10 17

7. Evaluation and testing of heat ventilation system 20-Jun-10 31-Aug-10 72

8. Preparation for final report 1-Sep-10 31-Oct-10 61

8.1 Writing skeleton of final report 1-Sep-10 7-Sep-10 8

8.2 Writing Literature search 8-Sep-10 15-Sep-10 8

8.3 Writing Introduction of report 16-Sep-10 22-Sep-10 8

8.4 Writing Main body of report 23-Sep-10 14-Oct-10 22

8.5 Writing conclusion and further study 15-Oct-10 20-Oct-10 5

8.6 Finalizing and amendments of report 21-Oct-10 31-Oct-10 10

9. Preparation for oral presentation 1-Nov-10 25-Nov-10 22

9.1 Review the whole project and decide for presentation 1-Nov-10 15-Nov-10 12

9.2 Prepare poster for presentation 16-Nov-10 25-Nov-10 10

Table 3.2: Detail Project Plan

- 18 -

Week 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44ACTIVITY

Legend

9.1 Review and extract important notes for presentation

9.2 Create poster and prepare for presentation

Main Task

Sub Task

8.6 Finalizing and Amendments of reort

9. Preparation of oral presentation

8.4 Writing Main Body of report

8.5 Writing Conclusion and Further study

8.2 Writing Literature review

8.3 Writing Introduction of reort

8. Preparation of Final Report

8.1 Writing skeleton of final report

6.2 Programming and evaluate on the model

7. Evaluation and testing of heat ventilation system

6. Integration and interaction with LM3s8962 evaluation board

6.1 Study of existing labview programming

6.3 Evaluation of the design model

5.2 Create and modify the model for HV system

5.3 Evaluation of HV system model

5. Design of the simulation model

5.1 Study existing model

Mar

Duration

4.2 Design the temperature sensor circuit

3. Preparation of Initial Report (TMA01)

4.1 Research on available temperature sensor

2.1 Find relevant reference books and IEEE online journals

2.2 Review and study relevant books and journals

4. Research on project components

Jan

1. Project Consideration and Selection

2. Literature Search

Feb

Actual

May Jun Jul AugApr Sep Oct Nov

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.

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.

- 20 -


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 CortexTM-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

in-circuit 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]

- 21 -


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

- 22 -


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.

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.

- 23 -


5.2 External Sensor Board

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.

- 24 -


5.2.1 Voltage Regulator

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:

- 25 -


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").

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.

- 26 -


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 also available in the plastic TO-92 transistor package. The LM35D is also

available in an 8-lead 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

- 28 -


power-of-ten 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 characterized by a single constant value, capacitance, measured in farads.

- 29 -


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 -


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 . 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

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Figure 7.17: External temperature monitor

The history of the temperature and the current temperature can be examined in terms

of Fahrenheit or Celsius.

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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 3.0V

Minimum single-ended, full-scale analog input voltage 0.0V

Maximum differential, full-scale an analog input voltage 1.5V

Minimum differential, full-scale analog input voltage 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 = .

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 = .

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 . 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 .

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.

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.

Figure 9.2: Corrected circuit for fan output

- 56 -

D3

R2

J4

J5DarlingtonTransistor

D3

R2

J4

J5

J6

DarlingtonTransistor5V


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.

- 59 -


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-has-changed/

[14] http://www.ni.com/arm

[15] http:// www.arm.com

- 60 -

http://www.arm.com/

http://www.ni.com/arm

http://www.ni.com/arm

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

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

http://www.farnell.com/

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

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

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


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 <Shift> 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.

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5. LM3S8962 Evaluation Kit Target Applications

Motion control

Factory automation

Fire and security

HVAC and building control

Power and energy

Transportation

Test and measurement equipment

Medical instrumentation

6. LM3S8962 Evaluation Kit Power

On-chip Low Drop-Out (LDO) voltage regulator, with programmable output user-adjustable from 2.25 V to 2.75 V

Battery-backed hibernation module with real-time clock and 256- bytes of non-volatile memory

3.3-V supply brown-out detection

Low-power options on controller: Sleep and Deep-sleep modes

Low-power options for peripherals: software controls shutdown of individual peripherals

User-enabled LDO unregulated voltage detection and automatic reset

On-chip temperature sensor

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kyawthuyathein fyp

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