CHAPTER 1

INTRODUCTION

1.1 Background of Study

Nowadays, in many situations, a communication link between two devices that

are reasonably far apart becomes essential. RF communication widely used because of

its wide range. The two devices do not need to be in line of sight in order to function

since it can cross many obstacles. It is very popular in various everyday applications

such as radios, cell phones and satellites. The application of RF communication in the

study of flood alert system can improve the response time of the public safety worker

and better way for communication between public safety worker and the flooded area.

The flood alert system improves the vision of public safety workers towards the current

situation in a flood area. It also can improve the flood alert system especially in a rural

area. The projects goal is to help public workers handle emergency situation like

floods efficiently and cut off response time should save a lot of life.

1

1.2 Problem Statement

In certain area, flash flood can occur which cannot be forecasted by The

Meteorological Department. Since the flood came suddenly, many locals face the flood

unprepared or at least informed about it right before the flood came while the local

authorities are delayed in action to respond to the flood. Some cable network and

telecommunication station might also damage during the flood; the cable might short

circuit due to conductive nature of water.

The flood alert system directly informs the authorities regarding the flood via a

wireless communication. During flood, road transport and telecommunications are

disrupted and electricity supply is short-circuited. Since it is much safer and will less

likely to experience damage during the flood, the wireless communication is much

more reliable than cable network. It directly informs multiple authorities responsible for

emergency situation like fire-fighter and paramedic from the water level indicator.

Through this direct contact system, a lot of time can be saved and the public safety

workers can respond in time, saving a lot of life in the process.

Figure 1.2.1: The current alert system

2

Rain gauge and

water level stations

Department of

Irrigation and

Drainage

Info-Banjir

website.

Short

message

system (SMS)

alert to

officers in-

charge.

Locals

Local

Authoritie

s

Figure 1.2.2: This project alert system

Figure 1.2.3: Flash flood in the city area

3

Rain gauge and

water level stations

Local

Authorities

1.3 Objective of Research

These are objectives for this project:

1. To implement software coding using Visual Basic.

2. To receive information regarding the water level through the receiver.

3. To deliver information about the current water level to the authorities via

wireless communication.

In order to achieve above objective, the following tasks will be implemented upon this

project:

1. Review on any articles or publication from books and websites related to usage

of Visual Basic software and transmission antennae.

2. Design and simulate both a simple program using Visual Basic and the receiver

schematic circuit.

3. Analyze the output of both programs and schematic circuit.

4. Construct the prototype.

5. Troubleshooting and modification of the prototype will be conducted if

necessary.

6. The result of the experiment will be collected and analyzed.

4

1.4 Scope of Study

Flood alert system that is designed in this project is suitable to be use near the

city where water source is abundant and is prone to flash floods. This flood alert system

is low in cost. With this system, citizen will be informed about the flash flood where

they can prepare to avoid it in time.

This project focuses on the communication system during flood. This project

centre around the PIC that controls the signal sent and retrieved. The PIC is

programmed and transferred to the simulation circuit to test the coding. Since this

project focuses the communication part of the whole system, the sensor that detects the

water level at the transmitter is replaced by buttons.

The signal produced by the button is then sent by using RF communication and

sent to computer for processing. At this stage, the VB software is implemented where

the signal received presents the hazard level of the floods

5

CHAPTER 2

MATERIALS AND METHOD

2.1 Methodology

The RF communication is used throughout this project where information is

received from a transmitter to a receiver and then amplified. The amplified frequencies

that represents to different hazard of flood are then sent to a computer. Using software

called Visual Basic, the different hazard levels are determined and shown, and the

information is sent to the respective authorities. This project only focuses on the

communication part between transmitter and receiver, not on the transmitter part where

the water sensor is used.

Stage 1 Stage 2 Stage 3

Figure 2.1.1: Block Diagram of the overall project.

6

The information

regarding the

flood is

transmitted via a

transmitter.

The information is

received via a receiver

and processed by a

computer.

The different hazard

level of flood is

determined using

Visual Basic.

2.1.1 Flow Chart

The flow chart for this project is as illustrated as in Figure 2.1.1. The data is

presented by numbers ranging from 0 to 9. This data can be adjusted at the transmitting

end of the communication system by using a mini slide switch. After it is sent to the

receiver and processed by the PIC, the data, depending on the number that was sent will

lead to different hazard of flood level.

If the number ranging from 0 to 3 is received, the system will recognized it as

Flooding is expected, be prepared at the computer screen which represents the 1st

level of hazard level. If the number received is from 4 to 6, the system will recognized

it as Flooding is expected, immediate action is required at the computer screen,

representing the 2nd

hazard level of the flood. Lastly, if the number range is 7 to 9, the

system will recognized it as Severe flooding, danger to life in which represents the 3rd

and last hazard level of the flash flood. If no number is received, it will wait the data to

be produced in the receiver part.

The data is shown at the computer screen via VB software. All the warning is

then sent to the local authorities for them to deal with and warn the locals about the

incoming flash flood

7

YES

NO

YES

NO YES

NO

Figure 2.1.1: Flow Chart of Flood Alert System.

8

START

Transmit information about the

current water level at the water

source. (Numbers ranging from 0

to 9)

Receive data of

different number.

1 - 3

4 - 6

7 - 9

Flooding is possible, be

prepared.

Flooding is expected,

immediate action

required.

Flooding is severe,

danger to life.

Control Part

(Computer)

Send warning to

local authorities

END

2.2 Experimental Setup

2.2.1 Proteus Simulation

Proteus is software for microprocessor simulation, schematic capture, and

printed circuit board (PCB) design. Component of system:

ISIS schematic Capture a tool for entering designs

PROSPICE Mixed mode SPICE simulation industry standard SPICE35

simulator combined with a digital simulator.

ARES PCB Layout PCB design system with automatic component placer, rip-

up and retry auto-router and interactive design rule checking.

VSM Virtual System Modelling lets co simulate embedded software for

popular micro-controllers alongside hardware design.

System Benefits Integrated package with common user interface and fully

context sensitive help.

9

2.2.1.1 Schematic Capture

The circuit is simulated using the Proteus software. Step below shows the step

to complete the simulation. The simulation is created on a simple circuit using Proteus

software.

1. Firstly, click on the P button as shown in Figure 2.2.1.1.1.

Figure 2.2.1.1.1: How to click to Pick from Library

2. To find the desired component, write the component name at the left side box as

shown in Figure 2.2.1.1.2. From there, it will display the component that have

the closes name as the written component name.

Figure 2.2.1.1.2: How to find component from library

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3. Place the chosen component on the schematic diagram as shown in Figure

2.2.1.1.3.

Figure 2.2.1.1.3: How to place components

4. Drag wire to connect the circuit as shown in Figure 2.2.1.1.4.

Figure 2.2.1.1.4: How to connect the components

5. After the circuit had been connected, push the run button to simulate the circuit

as shown in Figure 2.2.1.1.5.

Figure 2.2.1.1.5: How to simulate the circuit

11

2.2.1.2 PCB Layout

From the created circuit on the Proteus software, the PCB layout can be created

with the same software. The following step describe on making a PCB layout after the

circuit simulation is done.

1. Find the component that have footprint so the wire will be easy to be connected

or use connector CONN-H2 component at each voltage source, input and

output. Click the net list ARES to transfer the circuit into the layout as shown

in Figure 2.2.1.2.1.

Figure 2.2.1.2.1: How to transfer schematic diagram to PCB layout

Figure 2.2.1.2.2: How to put connector.

2. To create a new layout, click the Generic Single Layer and OK button as

shown in Figure 2.2.1.2.3.

12

Figure 2.2.1.2.3: How to create new layout

3. To set the size of PCB layout, board edge has to be created. Click the bottom

left box and then click the Board Edge at the left side as shown in Figure

2.2.1.2.4.

Figure 2.2.1.2.4: How to set the PCB layout size

4. Place the component according to the circuit given to make sure that the wires

are not overlap. The component also can be arrange and place as it is. After all

the component had been placed, click the AUTOROUTE button to create the

track as shown in Figure 2.2.1.2.5.

13

Figure 2.2.1.2.5: How to place component so that the wire not overlap to each

other

5. Click the Begin Routing button to create the track as shown in Figure

2.2.1.2.6. The blue colour represents the track connection.

Figure 2.2.1.2.6: How to create the track for the PCB layout

6. If there is a path that is not connected, it must be connected manually. Usually a

red circle will show the location of disconnected path. Click at the bottom left

and select Board Edge to make the size of the PCB as shown in Figure

2.2.1.2.7.

14

Figure 2.2.1.2.7: The component track

7. Gerber file can be created if there is no error in the layout. To create Gerber file,

click the output and choose Gerber / Excellon output as shown in Figure

2.2.1.2.8.

Figure 2.2.1.2.8: How to expect the layout to the Gerber file

8. If there is no fail mentioned as shown in, click the close button and proceed.

If there is fail mentioned, locate the error and fix it.

15

9. Next, make sure the bottom copper had been click to make the Gerber file.

Lastly, click OK button as shown in Figure 2.2.1.2.9.

Figure 2.2.1.2.9: Dialog box for Gerber file

16

2.2.2 Microsoft Visual Basic 2008 Express Edition

This project uses VB to show the data received on the computer screen. The

following step describe on making a new project.

1. Open Visual Basic software. Click File on the menu bar, and then click New

Project. Choose the icon Windows Forms Application from the Template list as

shown in Figure 2.2.2.1

Figure 2.2.2.1

.

2. Choose Common Controls on the left side and place it on the design as shown in

Figure 2.2.2.2.

17

Figure 2.2.2.2

3. Double click the on the button for programming. A programming window will

appear as shown in Figure 2.2.2.3.

Figure 2.2.2.3: Current status of the software

4. Program the button. For this example the program closes the window when it is

click as shown in Figure 2.2.2.4. If an error exists, locate it and fix it by referring to

reference book.

Figure 2.2.2.4

18

2.2.3 MPLAB X IDE

MPLAB X IDE is a software program that develops applications for Microchip

microcontrollers and digital signal controllers. It supports all 8-bit PIC microcontroller.

1. Open the MPLAB X IDE, click main menu and select File > New Project.

2. Choose the project type. From the categories choose Microchip Embedded.

From the project column, choose Standalone Project. Then Next as shown

in Figure 2.2.3.1.

Figure 2.2.3.1: Step to start a new project on MPLAB

3. Select device > Family > All Families. Then Device > PIC 16F877A > Next as

shown in Figure 2.2.3.2

Figure 2.2.3.2: Step to select a device

18

4. Select Tool > Hardware Tool > PICkit 2 > Next as shown in Figure 2.2.3.3.

Figure 2.2.3.3: Step to choose hardware tool

5. Select Compiler > XC8 > Next as shown in Figure 2.2.3.4.

Figure 2.2.3.4: Step to select compiler

6. Select Project Name and Folder > Project Name > Project Location > Project

Folder > Finish > Done as shown in Figure 2.2.3.5.

20

Figure 2.2.3.5: Step to select project name and folder

21

2.3 Equipment and Components

No. Components Quantity

1. IC PIC 16F876A 2

2. IC Socket-28 pin (slim) 2

3. Crystal H49S (Low Profile) 20MHz 2

4. Voltage Regulator +5V 2

5. Diode 1N4007 2

6. Diode 1N4148 2

7. Electrolytic Capacitor 16V 10uF 2

8. Ceramic Capacitor 0.1uF 4

9. Ceramic Capacitor 30pF 4

10. 2510 PCB Connector 2 Ways 2

11. Mini Slide Switch (PCB) 2

12. DC Plug (Adaptor Socket) 2

13. 6x6x1 Push Button 2 Pins 5

14. LED 3mm Green 2

15. Resistor 1/4W 220R 16

16. Resistor 1/4W 10K 2

17. Resistor 1/4W 4K7 5

18. Single core cable (Antenna) 18cm 2

19. 7 Segment Display 0.5(C/Cathode) 2

20. RF Receiver 315MHz 1

21. RF Transmitter 315MHz 1

22. 10 Ways Straight Box Header 2

23. 3mm screw & nut 8

24. Header Pin 4 way (R/A) 1

25. Header Pin 3 way 1

Table 2.3.1: List of Components for Receiver and Transmitter Part

22

No. Components Quantity

1. AC to DC adaptor 1

2. UIC00A Programmer 1

Table 2.3.2: List of Components for microC PIC programming

No. Components Quantity

1. RS232 Shifter 1

2. RS232 to USB 1

Table 2.3.3: List of components for connecting the circuit to computer

23

2.3.1.1 PIC 16F876A

PIC16F876A is the main component and act as the brain in this project circuit.

It controls the operation between the transmitter and receiver of the project.

Figure 2.3.1.1.1: PIC16F876A

Parameter Value

Digital Communication 1xA/E/USART, 1 x MSSP(SPI/I2C)

Program Memory (KB) 14KB or 8K 14-bit Flash

RAM (bytes) 368

Data EEPROM (bytes) 256

Timers 2 x 8 bit, 1 x 16-bit

Comparators 2

Max Crystal Speed 20MHz

Capture/Compare/PWM 2 x CCP

Pin Count 28

Table 2.3.1.1: The features of PIC16F877A

24

2.3.1.3 Crystal H49S (Low Profile) 20MHz

The use of Crystal H49S (Low Profile) 20MHz is to provide clock at 20MHz. It

is resistance welded type crystal units. It is mass produced and low in cost.

Figure 2.3.1.3.1: Crystal H49S (Low Profile) 20MHz

25

2.3.1.4 Voltage Regulator +5V

Voltage regulator is designed to automatically maintain a constant voltage

level. It can be simple feed-forward or may include negative feedback control loop.

Figure 2.3.1.4.1 show a voltage regulator and Figure 2.3.1.5.2 show its circuit form.

Figure 2.3.1.4.1: Voltage Regulator

Figure 2.3.1.5.2: Voltage Regulator +5V circuit

26

2.3.1.5 Diode 1N4007

The 1N4007 diode is a general purpose silicon rectifier diode. It is commonly

used in AC adapter in common household appliances. Figure 2.3.1.5.1 shows a 1N4007

diode.

Figure 2.3.1.5.1: Diode 1N4007

27

2.3.1.6 Diode 1N4148

The 1N4148 Diode is a standard silicon switching diode. This component has a

much higher leakage current since leakage is almost never a desirable property. It is

known as a special diode that allows the flow of current in a forward path and also in

reverse direction thus producing breakdown voltage. Figure 2.3.1.6.1 shows a 1N4148

diode.

Figure 2.3.1.6.1: Diode 1N4148

28

2.3.1.7 RF Receiver 315MHz

The RF Receiver as shown in Figure 2.3.1.7.1 is very small in dimension. The

low cost RF receiver can be used to receive RF signal from transmitter at the specific

frequency which determined by the product specifications.

Figure 2.3.1.7.1: RF Receiver 315MHZ

29

2.3.1.8 RF Transmitter 315MHz

The RF Transmitter as shown in Figure 2.3.1.8.1 is both small and low-cost. It

also has a wide operating voltage range (3V-12V).

Figure 2.3.1.8.1: RF Transmitter 315MHz

30

2.3.1.9 Capacitor

2.3.1.9.1 Ceramic Capacitor

A ceramic capacitor is a fixed value capacitor in which ceramic material acts as

the dielectric. It is constructed of two or more alternating layers of ceramic and a metal

layer acting as the electrodes. The composition of the ceramic material defines the

electrical behaviour and therefore applications. Figure 2.3.9.1 shows a ceramic

capacitor.

Figure 2.3.9.1: Ceramic Capacitor

31

2.3.1.9.2 Multilayer Capacitor

Multilayer capacitors (MLCs) overcome this problem by interleaving dielectric

and electrode layers. The electrode layers are usually palladium or a palladium-silver

alloy. These metals have a melting point that is higher than the sintering temperature of

the. Figure 2.3.9.2 shows a multilayer capacitor.

Figure 2.3.9.2: Multilayer Capacitor

32

2.3.1.10 RS 232 Shifter

RS232 is a serial-port interface. It allows a microcontroller that uses RF

transmitter and RF receiver to communicate with computer. Figure 2.3.1.10.1 show the

schematic diagram of RS 232 shifter and Figure 2.3.1.10.2 show the RS 232 shifter

itself.

Figure 2.3.1.10.1: RS232 schematic diagram

Figure 2.3.1.10.2: RS232 Shifter

33

2.3.1.11 RS232 to USB Converter

RS232 to USB converter send data from RS232 Shifter to USB, since many

latest computers does not have DB9 connector. Figure 2.3.11 show a typical USB

Converter.

Figure 2.3.11: RS232 to USB Converter

34

2.3.1.12 LED

LED or Light Emitting Diode is a semiconductor light source. It is usually used

as an indicator lamp in many devices. Figure 2.3.1.12 shows a LED.

Figure 2.3.1.12: LED

35

CHAPTER 3

CIRCUIT DESIGN AND OPERATIONS

3.1 Schematic Diagram

Figure 3.1.1 below shows the schematic diagram for the transmitter part.

Figure 3.1.1

36

Figure 3.1.2 below shows the schematic diagram for the receiver part.

Figure 3.1.2

37

3.2 Circuit Operations

1. Figure 3.2.1 below shows the schematic of transmitter circuit in Proteus

simulation. After the circuit is switched on, the number at the 7-segment

initially is 0. It can be increase by pushing the push button at R12 and decrease

by pushing the push button at R11. The function of push button at R10 is to

initiate sending of the data. The data is processed and then transmitted by the

RF transmitter.

Figure 3.2.1: Transmitter circuit

2. Figure 3.2.2 shows the schematic of receiver circuit in Proteus simulation. After

the circuit is switched on, the RF receiver will receive data sent by the

transmitter. The data is processed and shows on the 7-segment.

38

Figure 3.2.2: Receiver circuit

39

3.3 PCB Designs

3.3.2 Procedures of Printed Circuit Board (PCB) Fabrications

Step 1:

Preparing the artwork by designing schematics and layout using Proteus software.

Step 2:

Generating Gerber File from the design.

Step 3:

Film Processing using photo plotter to process a film. The films are generated from

Gerber data.

a. Lift the photo lid and place fill on the drum fix it by masking tape along the top

and bottom edge.

b. Rotate the drum back to its initial position, and close the lid and set the switch

to auto mode.

c. After completing the photo plot film, open the lid and remove film. Immediately

using developer and fixed chemical to process film.

Step 4:

Cutting PCB.PCB board must be cut depend on circuit design size using PCB Shear

cutter.

a. Ensure the handle is firmly clamped to top bar of shear by the handle clamp and

place the handle in the vertical position.

b. Insert PCB board on the feed bed against the ruler and adjust to cut size using

ruler.

c. Hold PCB with one hand and pull the handle down with the other hand slowly

until horizontal position (PCB board will be cut).

40

d. Release the handle back to vertical position.

e. Remove the PCB board.

Step 5:

The PCB board needs to go through the Clean/Brush and Drying process. Wash the

board under tap with scotch brite.

a. Before placing the PCB board, close the top lid and turn on water supply,

MAINS, BRUSH, OSCILLATOR, CONVEYOR and DRYER. After that set

the oscillator and conveyor speed.

b. Put the PCB board through the brush cleaning machine, make sure copper clad

on top before input.

c. Twist the Brush Pressure Adjuster knob to adjust brush pressure on board

(Clockwise for tighter and anticlockwise for looser)

d. Remove board from the exit end of machine.

e. Repeat process (b) until PCB board is clean free from finger print.

f. Turn on the machine switch and press Heating button. Wait about 10 seconds

for heat up.

g. Finally, put the wet PCB board through conveyor PCB Dryer on right hand side

of the machine and collect dry PCB board from other end

Step 6:

Apply dry film photo resist on copper PCB board surface by using laminator. Make

sure there is no bubble after laminated.

a. Switch on the machine.

b. Set the temperature to 105. Press MEAS to measure the actual temperature of

rollers.

c. Set the roller speed to number 3

d. Put board into Board Dryer Machine to ensure PCB board is free of grease or

oxides before dry film lamination.

41

e. When temperature rollers are 105, insert PCB board between rollers and press

RUN.

f. Allow roller to run until the whole PCB board is covered with dry film

laminator.

g. Allow a little bit more of dry film to run then press STOP. This makes it easier

to cut dry film from the groove behind the machine.

h. Use a blade to cut off the dry film from the groove behind the machine.

i. Cut off excess dry film from the PCB board.

j. Switch OFF machine after use and close with black cloth.

Step 7

There is a lot of method for transferring the layout or artwork onto copper board. One

of them is by using UV exposure process.

a. Place a film toner face down o a laminated PCB board. Use transparent tape to

hold the film in position. Make sure3 that the laminated PCB board. Use

transparent tape to hold the film in position. Make sure that the film is oriented

correctly (tape on top over artwork/ top side of negative artwork).

b. Place PCB board in a vacuum UV exposure unit and run it for 20 seconds.

When UV light strikes the panels. It hardens the resist.

c. Remove the negative film and protective film from PCB board to reveal the

photo resist after exposure.

Step 8:

The exposed photo resist is removed chemically using developer, leaving the layout

photo resist on copper which is call Developer Process using Rota-spray Developer.

The parts that are to be etched should look like completely clean copper, no residue. A

well developed board should have solid traces and a clean copper background.

a. Make sure set the temperature at 35C (wait 10 minutes for heat-up) before

leave exposed PCB board.

42

b. Set timer for 1 min (over developer will damage the photo resist coating). The

developer removes the unexposed photo resist dry film. The areas of PCB board

that have been exposed to UV light will be hardened and cannot be removed by

the developing solution.

c. Put the PCB board into BOARD HOLDER, then insert BOARD HOLDER to

develop chamber.

d. Press START/STOP button to start developer. (Timer will count-down to

zero).

e. After processing has finished it is best to lift the board holder and leave residue

liquid drain into the develop chamber before putting to wash chamber.

f. Insert board holder to wash chamber, then turn ON the spray wash switch.

Step 9:

Next step is Etching Process. The board is placed in an etcher, which is a machine that

washes warm Ferric Chloride over the board eating away any exposed copper.

a. After washed, leave PCB board into etching machine conveyor until exit the

machine. The Etching removes machine removes the exposed copper.

b. The photo resist dry film protects the copper circuitry from being etched.

c. Turn on isolator switch to turn ON the machine.

d. If SUMP-LOW indicators turn on it means Ferric Chloride need to top up to

the set level.

e. Press START button and set temperature to 45C.

f. Turn ON conveyor and set the speed between 0-2 m/min.

g. Switch ON water supply.

h. Press START button next to MAINS ON the Ferric Chloride and water

start spraying now.

i. Insert PCB board to the right hand side of the machine.

j. Take out PCB board from etching machine.

k. Repeat step (h) & (i) if copper is not fully etched.

Step 10:

43

This process will remove all the photo resist from the etched circuit board revealing the

cooper that makes circuit on the board. The process is called Photo resist Stripper.

a. Leave PCB board into tank 1 (photo resist stripper at 45C which contain 1 liter

Photo resist Stripper a 4 litre water) approximately 3 minutes until all photo

resist film are removed. The photo resist stripper removed all photo resist dry

film on PCB board.

b. Put PCB board into tank 2 (Acid cleaner at 40C which contain 1 iter 1320 Acid

Cleaner and 4 litre deionizer water), immerse for 4 minutes until the board clean

and ready to prepare the copper for plating.

c. After that transfer PCB board into tank 3 (Micro Etch at 35C which contain

1305500g Micro Etch Solution and 5 litres water); immerse 4 minutes until the

board clear to have perfectly clean copper and ready to accept the chemical tin

plating.

d. Finally, transfer PCB board into tank 4 (Immersed Tin at 50C- which contain

PC 168 450g immerse Tin Powder and 5 litres deionizer water), immersed for 5

minutes.

e. Make sure, for each step, take out PCB board and spray wash for about 1

minute.

Step 11:

PCB board is applying a Dryer Process. This process required a dryer machine.

a. Turn on the machine via ON/OFF switch.

b. Press Heating and wait until about 10 second for heat up.

c. Insert wet PCB board on right hand side of the machine.

d. Collect dry PCB board from other end.

Switch OFF the machine after use.

44

CHAPTER 4

RESULT AND DISCUSSION

4.1 Software Simulation Result

4.1.1 Proteus

1. Figure 4.1.1.1 below shows simulation for voltage supply. The power source

that could be supplied for this circuit board is between 7V to 15V. Higher input

voltage will result in increase of heat at LM7805 voltage regulator. Typical

voltage would be 12V. However, with 12V supply, the LM7805 regulator will

still produce heat. In the figure below, the simulation supply 11.203V to

LM7805 voltage regulator and it regulates it to 5V.

Figure 4.1.1.1: Simulation result for voltage supply.

45

2. Figure 4.1.1.2 below show the simulation for push button. One I/O pin is

needed for one push button as input of PIC microcontroller. The I/O pin should

be pull up to 5V using a resistor and this will result an active-low input. When

the button is pressed, reading of I/O pin will be in logic 0, while when the

button is not pressed, reading of I/O pin will be logic 1.

Figure 4.1.1.2: Simulation for push button

46

4.1.2 Visual Basic

1. Figure 4.1.2.1 below shows the overall program for this project. An input is

insert to the program as shown on the Figure 4.1.2.2.

Figure 4.1.2.1: The overall program

Figure 4.1.2.2: Insert input

2. When the input with the range between 1 to 3 is insert, the display button is

click to show which Led is ON as shown in Figure 4.1.2.3.

47

Figure 4.1.2.3: Program display warning symbol

3. Led 1 is ON, because is in range of 1 to 3.

4. Warning Statement displays the status condition of the input as shown in

Figure 4.1.2.4.

Figure 4.1.2.4: The program displays the warning status

5. Input range between 4 to 6 turns Led 2 ON and display the warning Flooding

is expected, immediate action required.

6. Those with input 7 to 9 turns Led 3 ON and display the warning Severe

Flooding, Danger to Life.

7. Reset button and Exit button. The Reset button is for resetting the

program and will revert to Figure 4.1.2.1, while the Exit button function is to

end the program.

48

4.2 Hardware Implementation Result

Figure 4.2.1 show the two hardware circuit for this project. The transmitter

circuit is on the left one and the receiver is the right one of the picture.

Figure 4.2.1: Tx and Rx circuit.

49

4.3 Circuit Testing and Troubleshooting

In order to test the communication circuit, the number can be increase and

decrease at the transmitter circuit. The same number is received at the receiver circuit

as shown in Figure 4.2.1.

In order to test the RS232 to USB connection, one of the RS232 is connected to

one of the USB as COM1 and another as COM2. The hardware connection is as shown

in Figure 4.3.1 where the transmitter pin (2) of the 1st RS232 to USB connection is

connected to the receiver pin (3) of the 2nd

one and vice versa. Software called Hyper

Terminal is used to show the sending and receiving of data. The connection between

the two is a success as shown in Figure 4.3.2. However, this software only exists in

Windows XP. Furthermore, the Ports (COM & LPT) in Device Manager do not exist in

Windows 7. Figure 4.3.3 show the hardware connection.

Figure 4.3.1: Connection between RS232 to USB

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Figure 4.3.2: Hyper Terminal Software

Figure 4.3.3: Hardware connection

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4.4 Data Analysis and Discussions

4.4.1 Data Analysis

The circuit successfully sent data from the transmitter to the receiver. The same

number that is produced from transmitter circuit is received at the receiver circuit. This

indicates that the radio communication at frequency of 315MHz between the two

circuits is a success. The connection of RS232 to USB had been proven successful only

on Windows XP. Windows 7 does not detect the USB and in Device Manager, no COM

is detected.

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4.4.2 Discussions

In Proteus software, the communication between transmitter and the receiver cannot

be simulated as there is no transmitter components exist or working in the library. The

power supplied for both transmitter and receiver circuit is 12V. However, the

PIC16F876A, RF Transmitter and RF Receiver all use voltage source of 5V and could

damage with 12V voltage source. In order to achieve this, a voltage regulator is added

to the circuit to regulate 12V into 5V.

In order to use the Visual Basic program, a RS232 serial-interface is used to transfer

the data from the circuit into the computer. However, many of today latest produced

computer does not have the DB9 connector that fits with RS232 serial-interface. To

solve this, a RS232 to USB converter is used to link the RS232 serial-interface with the

computer since all modern computers have USB interface. The RS232 needs a

controller between the communication circuit and PC.

The Visual Basic needs input and output (I/O) programs to receive data from the

serial COM Port. When starting this project, a lot of problems need to encounter in the

process, especially the designing of the program using the Visual Basic 2008 Software.

Firstly, the design must be connected to the button which in this case was the display

button. There are no problems for the typing of integers in the textbox as the program

wants the input in numbers. The main problem is to connect the button to display the

picture of a chosen Led to be display when a certain input is insert, but the input

displayed the same Led picture when different range of input was enter. OrElse is

confused to pick either 0 or numbers lower than 3.eventually the program should use

AndAlso because it need both ranges as written below.

If Input = 0 AndAlso Input

CHAPTER 5

CONCLUSION AND RECOMMENDATION

5.1 Conclusion

As a conclusion, students have been able to design both transmitter and receiver

circuit for Flood Alert System project. The purpose of this project is to warn the local

authorities on the flash flood in shot time and at a very low cost is achieved. During the

process of doing this project students have learned to use a wide variety of software like

Proteus, Visual Basic and MPLAB. Students also have been able to turn a circuit design

from an idea into reality. This project teaches students to take an alternative if facing a

problem.

Students now understand the basic of Radio Frequency communication using

PIC16F876A as a controller. This project teaches students to do a project step by step

which is good for the future of the students. Other than that students understand the

basic use of PIC16F876A as a microcontroller device.

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5.2 Recommendation

This project allows authorities to receive information regarding flash floods via

wireless communication and inform the locals to prepare. This project can save a lot

life and monetary damages, not to mention it is low cost and simple. It also makes the

rescuer job a lot easier since most people would already save themselves. It is very

useful to the people who do not want to get caught in the flood in their car or in their

premises.

This project can be further improved by sending the information not only to

local authorities but also to the people who live in the flood prone locations. This

information can be sent to them by using Short Message Service or SMS to them since

most people own cellular phone. This not only save the time spent by the local

authorities to inform the locals but also allocate them a lot of time to react to the

upcoming flash flood. If the SMS need to be sent to the locals, the circuit design needs

to be modified by adding a Global System for Mobile Communication (GSM) modem.

The transmitter and receiver used in this project can only communicate up to a

couple of meter away from each other. This can be improved by placing both of them at

high communication tower or simply high building. To have the best result, place both

of them at a high tower which is build on high building in the city are or mountains in

the rural area.

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REFERENCES

Textbook

1. G.K. Mithal. Introductory Electrical Engineering.

2. Alexander Sadiku. Fundamentals of Electric Circuits. Fourth Edition. McGraw-

Hill International Edition.

3. Diane Zak. (2008). Microsoft Visual Basic 2008 : Reloaded. Cencage Learning.

4. Qizheng Gu. (2006). RF System of Tranceiver for Wireless Communication.

Springer.

5. Andrei Grebennikov. (2004). RF and Microwave Power Amplifier Design.

McGraw Hill.

6. Jon B. Hagen. (2009). Radio-Frequency Electronic. Cambridge University Press.

Websites

1. http://www.hardwaresecrets.com/article/317

2. http://visualbasic.about.com/od/applications/a/whatisvb.htm

3. http://www.electronics-tutorials.ws/amplifier/amp_5.html

4. http://www.circuitstoday.com/transistor-amplifier

5. http://www.falstad.com/circuit/e-schmitt.html

6. http://www.nuffieldfoundation.org/practical-physics/transistor-current-amplifier

7. http://electronics.howstuffworks.com/relay.htm

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APPENDICES

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