DESIGN AND IMPLEMENTATION OF REMOTE …...control system (i.e., mobile phone based control...

DESIGN AND IMPLEMENTATION OF REMOTE

MULTIPLE LOADS CONTROL SYSTEM

USING MOBILE PHONE

Debasish Das

Department of Electrical & Electronic Engineering

Dhaka University of Engineering & Technology,

Gazipur-1700,Bangladesh.

June, 2015

ii

DESIGN AND IMPLEMENTATION OF REMOTE MULTIPLE LOADS

CONTROL SYSTEM USING MOBILE PHONE

A Project Report submitted to the Department of Electrical and Electronic Engineering in

partial fulfillment of the requirements for the degree

Of

MASTER OF ENGINEERING IN ELECTRICAL AND ELECTRONIC ENGINEERING

By

Debasish Das

Student No: 052201P

Under the supervision of

Dr. Md. Monirul Kabir

Assistant Professor

Department of Electrical and Electronic Engineering

Dhaka University of Engineering and Technology

Department of Electrical and Electronic Engineering.

DHAKA UNIVERSITY OF ENGINEERING AND TECHNOLOGY,

GAZIPUR – 1700, BANGLADESH

iii

The Project Reportentitled “DESIGN AND IMPLEMENTATION OF REMOTE

MULTIPLELOADS CONTROL SYSTEM USING MOBILE PHONE” submitted by Debasish

Das, Roll no: 052201P, Session: 2005-2006 has been accepted as satisfactory in partial

fulfillment of the requirement for the degree of MASTER OF ENGINEERING IN

ELECTRICAL AND ELECTRONIC ENGINEERING on June 10, 2015.

BOARD OF EXAMINERS

1

.

Professor Dr. Md.SaifuddinFaruk

Head


Dhaka University of Engineering and Technology(DUET)

Chairman

2

.

Dr. Md. Bashir Uddin

Professor



Member

3

.

Dr. Md. Raju Ahmed

Associate Professor



Dr. Md.MonirulKabir

Assistant Professor

Department of Electrical and electronic Engineering


Member

Member

(Supervisor)

4

.

Professor Dr. Md. ShahidUllah

Head

Department of Electrical and electronic Engineering

Islamic University of Technology (IUT), Gazipur

Member

(External)

iv

CANDIDATE’S DECLARATION

I hereby declare that this project or any part of it has not been submitted elsewhere for the

award of any degree or diploma or publication.

_________________________________________

Debasish Das

Student ID: 052201P

v

ACKNOWLEDGEMENT

I would like to express my gratitude and profound indebtedness to my supervisor Dr. Md.

Mnirul Kabir, Assistant Professor, Department of Electrical and Electronic Engineering of

Dhaka University of Engineering and Technology (DUET), Gazipur, Bangladesh for his

guidance, inspiration and helpful support throughout my project work without which the work

could not be completed.

I would like to express my gratitude and specially thanks to Dr. Anwarul Abedin, Professor,

Dept. of EEE, DUET, for his cordial help and valuable suggestions. I shall ever grateful to

him because of his random support to completion this project work. I would like to thanks

librarian of DUET to use library.

vi

ABSTRACT

In this project, a mobile phone based control system (MPCS) has been designed and

implemented to automatically communicate with the multiple electrical remote loads. The

proposed MPCS uses a microcontroller that is mainly connected with Double Tone Multiple

Frequency circuit, Global System for Mobile communication (GSM) modem, and multiple

electrical loads. The prime role of MPCS is to control the remote loads in respect of ON/OFF

switching using the mobile phone-based interface (MPI). To control the remote loads, the user

should send an authentication code through DTMF circuit along with the desired

function/action via GSM. After completed the proper authentication, user using MPI transmits

the commands to a microcontroller that performs the desired function/action. Furthermore, as

a feed-back information, MPCS provides the current status of all of the remote loads via short

messaging system (SMS) by the assistance of Tri-band Modem which is connected with

microcontroller as well as the user’s MPI through GSM. Additionally, the similar information

can also be provided through LCD display system. In order to evaluate the performance of

MPCS, a prototype module has been implemented, where four electrical lamps are considered

as the electrical loads. Experimentally, it was found that MPCS can effectively control the

remote electrical loads as well as provide the current status accurately using SMS.

vii

Contents

Board of Examiners iii

Declaration iv

Acknowledgement v

Abstract vi

List of Figures ix

List of Tables x

Nomenclature xi

Chapter 1 Introduction

1.1 Introduction 1

1.2 Motivation 3

1.3 Objective of the work 4

1.4 Significance of MPCS 4

1.5 Advantages of MPCS 5

1.6 Organizations

Chapter 2 Mobile Phone based Control System-MPCS

2.1 Proposed System-MPCS 6

2.1.1 Method used in MPCS 11

2.1.1.1UART method 11

2.1.1.2 AT command 12

2.2 List of components 13

2.3 Description of the components 14

viii

2.3.1 DTMF circuit 14

2.3.2 PIC16F877A microcontroller 14

2.3.3 Crystal oscillator 17

2.3.4 Electrical relay 17

2.3.5 SIM300CZ tri-band modem 19

2.3.6 LCD Display (16x2) 21

2.3.7 ULN2003 driver 23

2.4 Description of the software 24

2.4.1 MikroC Pro for PIC 24

2.4.2 Proteus 7.1 25

Chapter 3 Software used in MPCS

3.1 Description of Proteus 27

3.1.1 Overview of Proteus design suite 28

3.1.2 Circuit construction and assembly 28

3.1.3 PIC16F877A parameter setting 29

3.1.4 Simulation 29

3.2 Proteus layout of MPCS 31

3.3 MikroC programming tools 31

3.3.1 Creating new project 32

3.3.2 Coding template 32

3.4 AT command 36

3.4.1 Types of AT command 37

3.5 Pseudo code of MPCS 38

3.6 Program coding 40

Chapter 4 Experimental studies

ix

4.1 Experimental studies 48

4.1.1 Implementation and observation of DTMF circuit 48

4.1.2 Controlling and displaying loads using mobile phone 49

4.1.3 Final implementation of MPCS 53

4.1.4 Observation of current load status 54

Chapter 5 Conclusion

5.1 Conclusion 55

5.2 Recommendation for future work 56

References 57

x

LIST OF FIGURES

Fig.2.1: Block Diagram of MPCS 8

Fig.2.2: Flowchart of MPCS 9

Fig.2.3: Complete DTMF input and output diagram 11

Fig.2.4 Pin diagram of PIC16F877A microcontroller 15

Fig.2.5: Crystal oscillator 17

Fig.2.6: Electrical relay 18

Fig.2.7: LCD display 21

Fig.2.8: LCD display interfacing with PIC16F877A 22

Fig.2.9: ULN2003 driver 23

Fig.3.1: Overview of Proteus software 29

Fig.3.2: PIC parameter setting on Proteus 30

Fig.3.3: MPCS shown in Proteus 31

Fig.3.4: New wizard MikroC Pro for PIC microcontroller 32

Fig.3.5: Createa new project in Mikroc Pro for PIC 33

Fig. 3.6: Creating a new project wizard in MikroC Pro for PIC on process 34

Fig.3.7: Defining a file name 34

Fig.3.8: Select location to store hex file 35

Fig.3.9: Final step of a new project wizard 35

Fig: 3.10: Coding of MPCS and built in condition 37

Fig: 3.11: Classifications of AT commands 37

Fig.4.1: Implementation and observation of DTMF circuit 49

Fig.4.2: Controlling and displaying loads using mobile phone 50

Fig.4.3: Final Implementation of MPCS 51

Fig.4.4: Observation of current load status 52

xi

LIST OF TABLES

Table 2.1 A recognized truth table of DTMF circuit. 10

Table2.2 Pin description of PIC16F877A16 16

Table 2.3 Pin-diagram of LCD display 22

Table 4.1 DTMF test datasheet 50

Table 4.2 Results of MPCS 53

xii

Nomenclature

DTMF Dual Tone Multi Frequency

ROM Read Only Memory

RAM Random Access Memory

CPU Central Processing Unit

EEPROM Electrically Erasable Programmable ROM

pF Peko Farad

μF Micro Farad

VSS Ground

SSP Synchronous Serial port

L Logic Low

H Logic High

Z High Impedance

X Don’t Cary

OSCI Oscillator Input

ICSP In Circuit Serial Port

RS Register Select Signal

LD Loop Disconnect

C Coulomb

F Farad

VDD DC Power

1

Chapter 1

Introduction

This chapter describes about the introductory concept of mobile phone based control system,

its motivation, purposes of this work, and so on.

1.1 Introduction

The accessing and popularity of mobile technology is increasing day by day throughout the

whole world. Although the mobile phone mostly uses for voice conversations, it can be

served in different areas, such as, mobile banking, money transfer, home security, fire hazard

security, load control, and so on. In this regard, controlling the remote electrical loads is also

very much promising area.

At the early stages, some efforts have been done to control the home and office appliances.

In these works, they try to introduce about the controlling system using the telephone

networks involving stand-alone telephone set. Though their efforts are appreciated, users

will be deprived from the facility of mobile network. To facilitate such things, nowadays,

research has been going on the mobile technology in the developed countries as well as

Bangladesh also. In 2009, EEE department of DUET initiated first [1][3] to implement a

project, where a single electrical load can be ON/OFF using ringing signal of a mobile

phone. The attempt is nice but affected by several problems, such as, identifying the ringing

signal will be difficult, while ranging, variety and volume of the signal are changed. In order

to overcome the above-mentioned problems, the next attempt was done in 2010 [2]. In [2],

T. Begum implemented an improved automation system that can operate home usable

electrical loads using short messaging system (SMS) from global system for mobile (GSM)

oriented mobile phone. Although this system is effective than the previous one, suffered by

some problems: (i) handling the system using SMS that is more difficult for inexpert persons

Chapter1: Introduction

2

to operate, (ii) no security option is maintained. That is to say, an unauthorized person can

easily run any load from somewhere.

In the same time, furthermore, C. K. Das [3] proposes two theoretical models for mobile

phone-based electrical loads but not implemented yet. The scope of their proposals is out of

displaying the current load status through LCD as well as SMS.A recent work presented in,

where controlling and getting the status of loads by sending the message through the GSM

network.

In regard to overcome the above problems of the models [1-3], we are interested to develop a

control system (i.e., mobile phone based control system-MPCS) that may control the

multiple electrical loads including the home appliances as well as the industrial heavy loads

from a remote distances using any operated mobile phone. The key aspects of this project are

that, (a) MPCS will operate as well as control a number of remote electrical loads more than

10 in numbers easily, (b) loads might be accessed from longer distance even from out of

Bangladesh, (c) easy handling for the inexpert persons because of the use of mobile phone

interface only, instead of SMS, (d) current status of the remote electrical loads could be seen

easily any time by SMS, and (e) a unique LCD displays show the current load status locally.

Finally, the implementation of this project uses the main device DTMF (Double Tone

Multiple Frequency) decoder, this project works covers and fills up the drawbacks of

previous works.

The aim of the proposed system, MPCS is to develop a cost effective solution that will

provide controlling of home/office appliances remotely and enable home security against

intrusion in the absence of homeowner. The system provides availability due to development

of a low cost system. In this regard, MPCS requires a reasonable cost that uses two mobiles

providing remote access to the home appliances with allowing proper homesecurity. Though

devices connected as home, office appliances consume electrical power; these devices

should be controlled as well as turn ON/OFF if required. Most of the time as it was done

manually, now it is a necessity to control devices more effectively and efficiently at anytime

from anywhere. In this system, our attempt is to develop a mobile phone-based home/office

appliance controller that differs from. This system is designed for controlling arbitrary

devices that includes two mobile set(i.e., one is user mobile, another is remote mobile)


3

connected through GSM mobile network, among which only the remote mobile is made of

the hardware connection with DTMF circuit and Microcontroller device. Specifically, “user

mobile” and “remote mobile” called as transmitter and receiver, respectively. In operation,

when the user makes a call to the remote mobile, then it receives the call automatically.

Then, the call is answered when the user enters a two/three digit password to access the

system for controlling the devices. As the caller press the specific password, it results in

turning ON/OFF the specific device. The switching of the specific device is performed by

the specific relay. In this system MPCS, security is preserved because of the dedicated user’s

passwords, which is known by the selected persons only. In addition, MCPS contains a Tri-

band Modem that has been connected with microcontroller physically as well as the user’s

modem through GSM in order to provide the current status of all of the remote loads via

SMS. The similar information can also be provided through LCD display system in MCPS.

1.2 Motivation

In Bangladesh, right now, the common practice is to operate the home and office appliances

manually. It is known that, the manual usage always requires the additional energy because

when the house/office owner is not available for a time, the existing electrical loads will be

operated unnecessarily. In this regard, mobile phone-based operation is much better than

manual practices. This kind of usage of mobile phone in our country is very rare. That’s

why, to operate the home and office appliances using mobile phone in Bangladesh, we are

interested to design and implement a project “Mobile Phone based Control System”, called

as MPCS that may control the various electrical loads efficiently. The proposed work is

formulated by two main techniques: (i) DTMF-based receiving circuit for the mobile phone

signals, and (ii) Microcontroller-based load control circuit.

1.3 Objectives of the work

The project MPCS is highlighted on basis of the following objectives:

i) To design and implement a control system by which home and office appliances

can be operated using mobile phone from the remote places.

ii) To simulate the circuit using Proteus software.

iii) To implement the circuit practically and verify the results.


4

1.4 Significance of MPCS

The significant aspects of MPCS, which are mentioned below:

First, it allows any kind of GSM-based mobile phone networks available in Bangladesh in

order to communicate with the remote loads automatically.

Second, no expert human is required at the remote places to be made contact with the sender

end.

Third, anyone can get the current status about the remote loads individually whether it being

ON/OFF mode from the sender end. Thus, using the proper handling of offices or household

electrical appliances, where people often used to forget to switch off, energy saving can be

possible.

Fourth, further extension for the number of remote electrical loads can be possible in MPCS

any time. It can be noted that, our system MPCS has a very good future for our country’s

respect whether it could be established commercially at the industrial areas. Thus, our

industrial management will be more dynamic as well as the production cost will be reduced.

1.5 Advantages of MPCS

According to our view, the advantages of MPCS are stated below:

Controlling electrical devices wirelessly.

Quick response is achieved.

Very Easy to making the circuit and controlling multiple loads.

Design is efficient and low cost.

Can use any branded any model handset.

Can be used any GSM operator supported SIM card.

Energy savings.

This system can be used in industrial application.

This system can be employed in houses or offices, where people often forget to

switch off electrical appliances.

We can control appliances from any place round the globe.

Operator get feedback SMS including all load status from circuit.


5

1.6 Organizations

This project report is organized by five chapters that are mentioned as follows:

Chapter 1 is the introductory chapter which gives an overall idea of the project, discussion

regarding previous works, objectives of my project work, significance of the Mobile Phone

based Control System-MPCS.

Chapter 2 briefs about Mobile Phone based Control System (MPCS), its block diagram,

step by step working procedure with flowchart and advantages of MPCS.

Chapter 3 describes highly about the software part of MPCS that has been used in its

working processes.

Chapter 4 presents the detailed experimental studies of MPCS including the observation of

current load status.

Chapter 5 finally concludes the discussion of MPCS with some future directions.

Chapter 2: Mobile Phone based Control System-MPCS

6

Chapter 2

Mobile Phone based Control System-MPCS

This chapter presents the detailed proposed system-MCPS including the block diagram and flow

chart. For hardware implementation, the required electrical components are also discussed here.

2.1 Proposed system-MPCS

The proposed system is used to access the remote electrical loads using the DTMF tone that is

generated when the user pushes mobile phone interfaces. This phenomena is occurred while the

mobile phones between two sides, that is to say, user side and remote side, are connected each

other. After that, this DTMF based controller controls the operation of multiple relays that

results in operating the remote electrical loads. However, the block diagram (see Fig. 2.1) and

flow chart (see Fig. 2.2) are presented in this chapter in regard to understand clearly about the

proposed system MCPS.

The overall system information of MPCS is presented in Fig. 2.1, which is composed by two

sections: (i) transmitter and (ii) receiver, whereas, receiver section is divided by five units, such

as, microcontroller, DTMF circuit, modem, display, and electrical loads. Specifically, rests of

four units among the five are connected with microcontroller. On the other hand, there are two

kinds of display facilities in the display unit of the proposed MPCS that instantaneously

provides the current status of the loads. Among them, one is SMS-based and another one is

LCD-based. The SMS-based display unit performs the task using Tri-band GSM modem with


7

the help of microcontroller, whereas, the second one just connected with microcontroller and

displays the current load status locally. The switching of different relays is being performed to

be ON/OFF the particular electrical load by the microcontroller.

However, for more comprehensibility about MPCS, the different steps can be described more in

detail by the flowchart shown in Fig. 2.2, which are stated as follows:

Step 1: At first, a power supply was made using a 220/12 volt AC transformer that has been

converted in to 12V DC using a bridge rectifier. For achieving pure DC supply, 1000µF

capacitor was used. To activate the microcontroller circuit, 5V DC supply is necessary. Thereby,

a voltage regulator LM7805 IC was used for supplying 5V DC continuously to the

microcontroller circuit.

Step 2: DTMF circuit has been completed in this step shown in Fig. 2.3 to decode the signal of

mobile phone binary coded output to the receiving end, where a number of electrical devices are

necessary, such as a MT8870D decoder IC, two resistor 100k , one 330k , two capacitors, one

3.58MHz crystal capacitor, one mobile phone connected with the headphone jack. After

completing the necessary connections, the desired output can be found according to the Table

2.1. To implement this section, a small bread board and 9 volt DC battery were used.

Step 3: In this step, the outputs of DTMF circuit are inserted to the microcontroller (e.g.,

PIC16F877A), which contains pins and its clock speed is 8MHz [4]. According to the project

aim, I used Micro C PRO for PIC software to burn program coding in the microcontroller. To

implement the whole project work, initially, a separate bread board was used. A tri-band GSM

modem was used that contains a SIM card. The activity of modem is that, whenever any request

comes from the transmitter unit to know the current status of the loads, then the modem

provides the status about the connected four loads with the help of microcontroller. A LCD

display interfacing in this circuit for monitoring load status for field operators.


8

Fig.2.1:Block Diagram of proposed MPCS. Here, R1, R2, R3, and R4 refer to the relay devices,

respectively, whereas, electrical loads are represented as L1, L2, L3, and L4, respectively

Microcontroller

(PIC16F877A)

DTMF

Decoder

(MT8870A)

SIM300CZ Tri Band Modular used

for sending the current load status

by SMS

Mobile Mobile

LCD Display Transmitter

unit Receiver unit

ULN2003

Relay

Driver

R1 L1

R2 L2

R3 L3

R4 L4


9

Fig. 2.2: Flow chart of MPCS.

Complete the DTMF Circuit and

Convert BCD Code

Insert the BCD Code into

Microcontroller

Initialization with

5V DC supply

Interface LCD Display

for Showing

ON/OFF status of Loads

Interface SIM 300CZ

Modem to generate

feedback SMS

Relay

On

Relay

Off

Inactive Mode

Return

No Yes

No Yes

Keyword= 1

?

Keyword= 2

?


10

Table 2.1: A recognized Truth Table of DTMF circuit.

Button Low DTMF High DTMF Binary Code Output

Frequency(Hz) Frequency(Hz) Q1 Q2 Q3 Q4

1 697 1209 0 0 0 1

2 697 1336 0 0 1 0

3 697 1477 0 0 1 1

4 770 1209 0 1 0 0

5 770 1336 0 1 0 1

6 770 1477 0 1 1 0

7 852 1209 0 1 1 1

8 852 1336 1 0 0 0

9 852 1477 1 0 0 1

0 941 1209 1 0 1 0

* 941 1336 1 0 1 1

# 941 1477 1 1 0 0

Step 4: In this stage, the output status of the remote electrical loads is displayed in LCD

Display (16x2), which is connected to the microcontroller. For this implementation,

programming language micro C for PIC was used.

Step 5: A tri band modem was used for feedback SMS that provides the ON/OFF status of

multiple loads. It takes two input signal, one from the DTMF circuit and another from the

PIC16F877A microcontroller, which can be burnt with proper coding for giving a uniform

output. On receiving these signals, the modem after that sends a feedback SMS to the user’s

mobile to be provided the status of multiple remote loads. In this project used four loads L1, L2,

L3, L4 against four relays R1, R2, R3, R4 and all of these four loads driven by one relay driver

ULN 2003.This relay driver connected with the microcontroller and driven four relays against

four and microcontroller receives the real data from ULN2003 relay driver and microcontroller

also interfacing with the SIM300CZ modem and given signal to the modem for generate SMS

with load status. For this communication there are two methods used:(i) UART method used

for hardware, and (ii) AT command used for software purpose.


11

Step 6: This step is the final step, in where, the total system is run properly. Here, while the

mobile keypad is pressed by user as “1”, the specific relay is operated that ultimately run the

corresponding electrical load. On the other hand, a particular relay is terminated with the

corresponding load, when the mobile keypad is pressed by “2”.

It is now clear that, the proposed system-MPCS is simpler in hardware architecture and cost-

effective for implementation. The operating process is not so difficult and easy for handling the

total system.

2.1.1 Method used in MPCS

2.1.1.1 UART method

A universal asynchronous receiver/transmitter, abbreviated UART is a piece of computer

hardware that translates data between parallel and serial forms. UARTs are commonly used in

conjunction with communication standards such as EIA, RS-232, RS-422 or RS-485. The

universal designation indicates that the data format and transmission speeds are configurable.

The electric signaling levels and methods (such as differential signaling etc.) are handled by a

Fig. 2.3: Complete DTMF input and output diagram.

https://en.wikipedia.org/wiki/Computer_hardware

https://en.wikipedia.org/wiki/Computer_hardware

https://en.wikipedia.org/wiki/Parallel_communication

https://en.wikipedia.org/wiki/Serial_communication

https://en.wikipedia.org/wiki/Electronic_Industries_Alliance

https://en.wikipedia.org/wiki/RS-232



https://en.wikipedia.org/wiki/Differential_signaling


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driver circuit external to the UART. A UART is usually an individual (or part of an) integrated

circuit (IC) used for serial communications over a computer or peripheral device serial port.

UARTs are now commonly included in microcontrollers. A dual UART, or DUART, combines

two UARTs into a single chip. An octal UART or OCTART combines eight UARTs into one

package, an example being the NXP SCC2698. Many modern ICs now come with a UART that

can also communicate synchronously; these devices are called USARTs (universal

synchronous/asynchronous receiver/transmitter).

Transmitting and receiving UARTs must be set for the same bit speed, character length, parity,

and stop bits for proper operation. The receiving UART may detect some mismatched settings

and set a "framing error" flag bit for the host system; in exceptional cases the receiving UART

will produce an erratic stream of mutilated characters and transfer them to the host system.

Typical serial ports used with personal computers connected to modems use eight data bits, no

parity, and one stop bit; for this configuration the number of ASCII characters per second equals

the bit rate divided by 10.Some very low-cost home computers or embedded systems dispense

with a UART and use the CPU to sample the state of an input port or directly manipulate an

output port for data transmission. While very CPU-intensive (since the CPU timing is critical),

the UART chip can thus be omitted, saving money and space. The technique is known as bit-

banging.

2.1.1.2 AT command

AT commands are used to control modems. AT is the abbreviation for Attention. These

commands come from Hayes commands that were used by the Hayes smart modems. The Hayes

commands started with AT to indicate the attention from the modem. The dial up and wireless

modems (devices that involve machine to machine communication) need AT commands to

interact with a computer. These include the Hayes command set as a subset, along with other

extended AT commands [6].AT commands with a GSM/GPRS modem or mobile phone can be

used to access following information and services. However, the AT command set can sub-

divided into four groups:

https://en.wikipedia.org/wiki/Integrated_circuit

https://en.wikipedia.org/wiki/Integrated_circuit

https://en.wikipedia.org/wiki/Serial_communications

https://en.wikipedia.org/wiki/Serial_port

https://en.wikipedia.org/wiki/Home_computers

https://en.wikipedia.org/wiki/Embedded_systems

https://en.wikipedia.org/wiki/Central_processing_unit

https://en.wikipedia.org/wiki/Bit-banging

https://en.wikipedia.org/wiki/Bit-banging


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1. Basic command set - A capital character followed by a digit. For example, M1.

2. Extended command set - An "&" (ampersand) and a capital character followed by a

digit. This extends the basic command set. For example, &M1. Note that, M1 is different

from &M1.

3. Proprietary command set - Usually starting either with a backslash (“\”) or with a

percent sign (“ ”) these commands vary widely among modem-manufacturers.

4. Register commands–Sr n, where r is the number of the register to be changed and n is

the new value that is assigned.

2.2 List of components

In order to implement the MPCS as hardware setup, the following electrical devices are

required:

Sl.

No. Component’s Name

Required

No.

Sl.

No.

Component’s

Name

Required

No.

01 MT8870D IC Decoder 01 12 9Volt Battery 01

02 Resistor (1/4 Watt

Carbon Film) 100K 02

13 LED 08

03 Resistor(1/4 watt Carbon

Film) 300K 01

14 5watt buld 04

04 Crystal Oscillator

3.58MHz 01

15 Mobile Nokia 01

05 Capacitor 0.1μF Ceramic

Disc 02

16 Mobile phone

headset

01

06 Capacitor 100μF 01 17 Soldering lead 20gram

07 PIC16F877A 01 18 NPN transistor 04

08 IC7806 01 19 Light Holder 04

09 Transformer

240VAC/12VAC 01

20 Project base 01

10 SIM300CZ Module 01 21 LCD Display 2line

16 digit

01

11 1N4007 Diode 05 22 SIM card 02

12 PCB 01 24 Connecting wire As required


14

2.3Description of the components

In MPCS, the description of the used electrical components for the hardware implementation is

stated below:

2.3.1 DTMF circuit

The total DTMF circuit was implemented in MPCS according to the Fig. 2.3.This DTMF (Dual

Tone Multi Frequency) decoder circuit identifies the dial tone telephone line and decodes the

key pressed on the remote telephone. Here, for the detection of DTMF signaling, the IC

MT8870DE was used that is a touch tone decoder IC. It decodes the input DTMF to 5 digital

outputs. The M-8870 DTMF decoder IC uses a digital counting technique to determine the

frequencies of the limited tones and to verify that they correspond to standard DTMF

frequencies [6]. The DTMF tone is a form of one way communication between the dialer and

the telephone exchange [6]. The whole communication consists of the touch tone initiator and

the tone decoder or detector. The decoded bits can be interfaced to a computer or

microcontroller for further application [6], [7],[8].

2.3.2 PIC16F877A microcontroller

In MPCS, microcontroller is a vital part in our system, where the model of PIC16F877A has

been used to automate the system. In this regard, the study of internal architecture of

PIC16F877A microcontroller is necessary. That’s why; this section represents the detailed pin

diagram of PIC16F877A microcontroller shown in Fig. 2.4 as well as the discussion of different

pins is mentioned in Table 2.2.

PIC 16F877 is a 40-pin 8-Bit CMOS FLASH Microcontroller from Microchip. The core

architecture is high-performance RISC CPU with only 35 single word1 instructions. Since, it

follows the RISC architecture, all single cycle instructions take only one instruction cycle. For

program branches, which take two cycles. 16F877 comes with 3 operating speeds with 4, 8, or

20 MHz clock input [8]. Since each instruction cycle takes four operating clock cycles, each


15

instruction takes 0.2 μs when 20MHz oscillator is used. It has two types of internal memories:

program memory and data memory. Program memory is provided by 8K words (or 8K*14 bits)

of FLASH Memory, and data memory has two sources. One type of data memory is a 368-byte

RAM (random access memory) and the other is 256-byte EEPROM (Electrically erasable

programmable ROM).The core feature includes interrupt capability up to 14 sources, power

saving SLEEP mode, and single 5V In-Circuit Serial Programming (ICSP) capability. The

sink/source current, which indicates a driving power from I/O port, is high with 25mA. Power

consumption is less than 2mA in 5V operating condition[12].

Fig. 2.4: Pin Diagram of PIC16F877A Microcontroller


16

Table 2.2:Pin description of PIC16F877A Microcontroller

Pin

No.

Pin Name Description Pin

No.

Pin Name Description

1 MCLR/VPP Master Clock Reset 21 RD2 PORTD.2

2 RA0/AN0 PORTA.0/Analog

Channel 0

22 RD3 PORTD.3

3 RA1/AN1 PORTA.1 /Analog

Channel 1

23 RC4/SD1/SDA SDA PORTC.4/SDI(for

SPI)/SDA(for I2C


Channel 2

24 RC5/SD0 PORTC.5/SDO(FOR

SPI)


Channel 3

25 RC6/TX PORTC.6/TX

6 RA4/TOCK1 PORTA.4 26 RC7/RX PORTC.7/RX

7 RA5/AN4 PORTA.5 27 RD4 PORTD.4

8 RE0/AN5 PORTE.0 28 RD5 PORTD.5



11 Vdd +3 TO+5v 31 Vss GND

12 Vss GND 32 Vdd +3 TO+5V

13 OSC1/CLKIN OSCILLATOR CON. 33 RB0/INT PORTB.O/EX.

INTERRUPT

14 OSC2/CLKOUT OSCILLATOR CON. 34 RB1 PORTB.1

15 RC0/TICK1 PORTC.0 35 RB2/PGM PORTB.2

16 RC1/CCP2 PORTC.1/CCP2 36 RB3 PORTB.3

18 RC2/CCP1 PORTC.2/CCP1 37 RB4 PORTB.4

18 RC3/SCK/SCL PORTC.3/SCK 38 RB5 PORTB.5

19 RD0 PORTD.0 39 RB6/PGC PORTB.6/ICSP

20 RD1 PORTD.1 40 RB7/PGD PORTB.7/ICSP


17

2.3.3 Crystal oscillator

A crystal oscillator shown in Fig. 2.5 is an electronic oscillator circuit that uses the mechanical

resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very

precise frequency. This frequency is commonly used to keep track of time (as in quartz

wristwatches), to provide a stable clock signal for digital integrated circuits, and to stabilize

frequencies for radio transmitters and receivers. The most common type of piezoelectric

resonator used is the quartz crystal, so oscillator circuits incorporating them became known as

crystal oscillators, but other piezoelectric materials including polycrystalline ceramics are used

in similar circuits.

Figure: 2.5: Crystal oscillators.

Quartz crystals are manufactured for frequencies from a few tens of kilohertz to hundreds of

megahertz. More than two billion crystals are manufactured annually. Most are used for

consumer devices such as wristwatches, clocks, radios, computers, and cell phones. Quartz

crystals are also found inside test and measurement equipment, such as counters, signal

generators, and oscilloscopes [11].

2.3.4 Electrical relay

A relay shown in Fig. 2.6 is an electrical switch that uses an electromagnet to move the switch

from the OFF to ON position instead of a person moving the switch. It takes a relatively small

amount of power to turn on a relay but the relay can control something that draws much more

power. Ex: A relay is used to control the air conditioner in your home. The AC unit probably

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

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

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

http://en.wikipedia.org/wiki/Piezoelectricity#Materials

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


18

runs off of 220VAC at around 30A. That's 6600 Watts! The coil that controls the relay may only

need a few watts to pull the contacts together. This is the schematic representation of a relay.

The contacts at the top are normally open (i.e. not connected). When current is passed through

the coil it creates a magnetic field that pulls the switch closed (i.e. connects the top contacts).

Usually a spring will pull the switch open again once the power is removed from the coil.

Fig. 2.6.Electrical relay

Relays (and switches) come in different configurations. Single Pole Single Throw (SPST) is the

simplest with only two contacts. Single Pole Double Throw (SPDT) has three contacts. The

contacts are usually labeled Common (COM), Normally Open (NO), and Normally Closed

(NC). The Normally Closed contact will be connected to the Common contact when no power is

applied to the coil. The Normally Open contact will be open (i.e. not connected) when no power

is applied to the coil. When the coil is energized the Common is connected to the Normally

Open contact and the Normally Closed contact is left floating. The Double Pole versions are the

same as the Single Pole version except there are two switches that open and close together.

Select a relay with contacts that can handle the voltage and current requirements of the load.

Keep in mind that some loads (such as motors) draw much more current when first turned on

than they do at steady state. Select a relay with a coil voltage and current that you can control

easily. Ex: If you want to turn on the AC unit with a 12VDC power supply get a 12VDC coil.

Coils will be rated for either AC or DC operation.


19

2.3.5 SIM300CZ tri-band modem

Designed for global market, SIM300CZ is a Tri-band GSM/GPRS engine that works on

frequencies of EGSM 900 MHz, DCS 1800 MHz and PCS 1900 MHz.SIM300CZ features

GPRS multi-slot class 10/class8capabilities and support the GPRS coding schemes CS-1, CS-2,

CS-3 and CS-4. Designed for global market, SIM300CZ is a Tri-band GSM/GPRS engine that

works on frequencies of EGSM 900 MHz, DCS 1800 MHz and PCS 1900 MHz.SIM300CZ

features GPRS multi-slot class 10/class8（optional）capability and support the GPRS coding

schemes CS-1, CS-2, CS-3 and CS-4 [9].

With a tiny configuration of 50mm x 33mm x 6.2mm, SIM300CZ can fit almost all the space

requirement in your industrial application, such as M2M, and mobile data communication

system etc. With the charge circuit integrated inside the SIM300CZ, it is very suitable for the

battery power application. The physical interface to the mobile application is made through a 60

pins DIP connector, which provides all hardware interfaces between the module and customers’

boards except the RF antenna interface.

The keypad and SPI display interface will give you the flexibility to develop customized

applications.

Serial port and Debug port can help you easily develop your applications.

Two audio channels include two microphones inputs and two speaker outputs. This can

be easily configured by AT command.

Charge interface

The SIM300CZ provides RF antenna interface with two alternatives: antenna connector and

antenna pad. The antenna connector is MURATA MM9329-2700. And customer’s antenna can

be soldered to the antenna pad. The SIM300CZ is designed with power saving technique, the

current consumption is as low as 2.5mA in SLEEP mode. The SIM300CZ is integrated with the


20

TCP/IP protocol, extended TCP/IP AT commands are developed for customers to use the

TCP/IP protocol easily, which is very useful for those data transfer application

Features:

Designed for global market, SIM300 is a Tri-band GSM/GPRS engine

Works on frequencies EGSM 900 MHz, DCS 1800 MHz and PCS 1900 MHz.

SIM300 features GPRS multi-slot class 10/ class 8 (optional) and supports the GPRS

coding schemes

CS-1, CS-2, CS-3 and CS-4.With a tiny configuration of 40mm x 33mm x 2.85mm ,

SIM300 can fit almost all the space requirements in your applications,

such as smart phone, PDA phone and other mobile devices

Features of GSM Kit:

This GSM modem is a highly flexible plug and play quad band GSM modem

Integration to RS232.

Supports features like Voice, Data/Fax, SMS,GPRS and integrated TCP/IP stack.

Control via AT commands(GSM 07.07,07.05 and enhanced AT commands)

Use AC – DC Power Adaptor with following ratings · DC Voltage : 12V /1A

Current Consumption in normal operation 250mA, can rise up to 1Amp while

transmission.

Interfaces

RS-232 through D-TYPE 9 pin connector,

Serial port baud rate adjustable 1200 to115200 bps (9600 default)

BRK connector for MIC & SPK, SIM card holder

Power supply through DC socket

SMA antenna connector and Murata Antenna ( optional)

LED status of GSM / GPRS module.


21

2.3.6 LCD display (16X2)

In embedded systems it is difficult to find status and errors generated by system software

running inside of microcontroller. It is also necessary in so many other applications where we

have to show results to users so that they can use system effectively. So there is a need of a

display unit. There are more than one ways of displaying status or results of the system and

LCD shown in Fig. 2.7 is one of these ways.

Fig. 2.7: LCD display

In this system, the used LCD having 16 columns and 2 rows. This is based on HD44780 LCD

controller. HD44780 is a generic dot matrix LCD controller made by Hitachi. This controller is

installed on other sizes of LCDs like 16×1, 16×4, 20×2, 20×4 etc. The interfacing between LCD

and PIC16F877A microcontroller is shown in Fig. 2.8, where the pin diagram of LCD is also

presented.

http://www.micro-digital.net/micro/wp-content/uploads/2012/08/LCD.jpg


22

Fig. 2.8: LCD Display interfacing with PIC16F877A

Table 2.3: Pin-Diagram of LCD display

Pin Symbol Function

1 Vss ground (0 V)

2 Vdd power (4.5 – 5.5 V)

3 Vo contrast adjustment

4 RS H/L register select signal

5 R/W H/L read/write signal

6 E H/L enable signal

7-14 DB0 – DB7 H/L data bus for 4- or 8-bit mode

15 A (LED+) backlight anode

16 K (LED-) backlight cathode

http://www.gophoto.it/view.php?i=http://www.8051projects.net/lcd-interfacing/lcd.png


23

2.3.7 ULN2003 driver

The ULN2003A is an array of seven NPN Darlington transistors capable of 500mA, 50V

output. It features common-cathode fly back diodes for switching inductive loads. It can come

in PDIP, SOIC, SOP or TSSOP packaging. In the same family are ULN2002A, ULN2004A, as

well as ULQ2003A and ULQ2004A, designed for different logic input levels.

Fig.2.9: ULN2003 relay driver IC

ULN2003 is known for its high-current, high-voltage capacity. The drivers can be paralleled for

even higher current output. Even further, stacking one chip on top of another, both electrically

and physically, has been done. Generally it can also be used for interfacing with stepper motor,

where the motor requires high ratings which cannot be provided by other interfacing devices.

https://en.wikipedia.org/wiki/Flyback_diode

https://en.wikipedia.org/wiki/PDIP

https://en.wikipedia.org/wiki/SOIC

https://en.wikipedia.org/wiki/SOP

https://en.wikipedia.org/wiki/TSSOP


24

Main specifications:

500 mA rated collector current (single output)

50 V output (there is a version that supports 100 V output)

Includes output fly back diodes

Inputs compatible with TTL and 5-V CMOS logic

2.4 Description of the software

For design and implementation of our MPCS we used MikroC Pro for PIC for programming and

Proteus 7.1 for simulation MPCS. The description of this software is following:

2.4.1 MikroC Pro for PIC

The MikroC PRO for PIC is a powerful, feature-rich development tool for PIC microcontrollers.

It is designed to provide the programmer with the easiest possible solution to developing

applications for embedded systems, without compromising performance or control.PIC and C fit

together well: PIC is the most popular 8-bit chip in the world, used in a wide variety of

applications, and C, prized for its efficiency, is the natural choice for developing embedded

systems. MikroC PRO for PIC provides a successful match featuring highly advanced IDE,

ANSI compliant compiler, broad set of hardware libraries, comprehensive documentation, and

plenty of ready-to-run examples [13].

Special features of MikroC Pro for PIC:

a. MikroC PRO for PIC allows you to quickly develop and deploy complex applications:

b. Write your C source code using the built-in Code Editor(Code and Parameter Assistants,

Code Folding, Syntax Highlighting, Auto Correct, Code Templates, and more.)

c. Use included MikroC PRO for PIC libraries to dramatically speed up the development:

data acquisition, memory, displays, conversions, communication etc.

https://en.wikipedia.org/wiki/Transistor%E2%80%93transistor_logic

https://en.wikipedia.org/wiki/CMOS

http://www.mikroe.com/download/eng/documents/compilers/mikroc/pro/pic/help/code_editor.htm


25

d. Monitor your program structure, variables, and functions in the Code Explorer.

e. Generate commented, human-readable assembly, and standard HEX compatible with all

programmers.

f. Use the integrated MikroICD (In-Circuit Debugger) Real-Time debugging tool to

monitor program execution on the hardware level.

g. Inspect program flow and debug executable logic with the integrated Software

Simulator.

h. Generate COFF(Common Object File Format) file for software and hardware debugging

under Microchip's MPLAB software.

i. Active Comments enable you to make your comments alive and interactive.

j. Get detailed reports and graphs: RAM and ROM map, code statistics, assembly listing,

calling tree, and more.

k. MikroC PRO for PIC provides plenty of examples to expand, develop, and use as

building bricks in your projects. Copy them entirely if you deem fit – that’s why we

included them with the compiler.

2.4.2 Proteus 7.1

The main theme of the Proteus 7.1 release is integration. Development has therefore been

focused on taking the various discrete parts of an electronic design and coupling them together

to achieve a better workflow. In order to achieve this, three major architectural changes were

necessary; a unified application framework, a common database and a live enlist

Special features of Proteus software

a. Proteus is an easy-to-use project and business intelligence environment. It's main

features are as follows:

b. A modern COTS/NDI solution that is built on .NET technology that uses OLE DB or

other similar technology to access, integrate and extend disparate data sources into

useful intelligence for more effective management and control of program management

information

http://www.mikroe.com/download/eng/documents/compilers/mikroc/pro/pic/help/mikroicd_introduction.htm

http://www.mikroe.com/download/eng/documents/compilers/mikroc/pro/pic/help/software_simulator.htm

http://www.mikroe.com/download/eng/documents/compilers/mikroc/pro/pic/help/software_simulator.htm

http://www.mikroe.com/download/eng/documents/compilers/mikroc/pro/pic/help/active_comments.htm


26

c. Possesses the ability to integrate information both horizontally and vertically, organize

data by user role and content and allow access to that data in accordance with position in

the organization, user role and need to know

d. Reduces life-cycle and support costs associated with business intelligence through an

easy-to-use template-based configuration that eliminates the need for specialized

development or hard-coding, allowing for rapid deployment and almost immediate ROI

e. Integrates data from disparate systems into a consolidated view that can be aggregated at

all levels for all stakeholders within and across the program team and the enterprise. The

stakeholders can drill down into the data and summarize the data at will to quickly

identify problems and trends

f. Provides virtually unlimited tailored views and reports to program specific needs using

the configurable user interface and business logic that interfaces with any existing OLE

DB-compatible table structure

g. Transforms data from any OLE DB compatible data source or format and be able to

transform that data for use without having to rekey the data. Data from different sources

should be easily compared to find mismatches and disparities

h. Organizes previously stove-piped information in a cohesive and intelligent manner. For

example, users need to be able to create integrated views of cost, schedule, risk, financial

and any other relevant program related data at any level of detail. Views should be saved

and used across the organization, a subunit of the organization or solely for a specific

user or set of users

Chapter 3: Software used in MPCS

27

Chapter 3

Software Part of MPCS

This chapter describes the detailed software part of MPCS, where two software tools were used,

such as, Proteus professional simulation tool and MicroC programming tool.

3.1 Description of Proteus

The Proteus professional simulation tool, that is to say, Proteus Design Suite (PDS) is wholly

unique in offering the ability to co-simulate both high and low level micro-controller codes in the

context of a mixed-mode SPICE circuit simulation. Using this virtual system modeling facility,

any kind of microcontroller based system model can be simulated with its real time data in order

to design and implement the system practically with lower costs [3], [6], and [10].

Usually, simulation of a designed model using PDS tool provides huge advantages for the future

implementations in setting hardware [10]. The reason is that, PDS always works on the real time

data of the different electrical components, in which the simulation outcome of the PDS of a

designed model is closed to similar to the original one. On the other hand, the PDS outcome can

be varied with varying the PDS design of a desired model within a very short time. Designing a

hardware model that is to say, physical setup of a hardware model is always expensive in cost

which might be increased if the proper electrical components with ratings are not determined. In

this case, PDS tool may provide optimistic solution that resulting an economical hardware

designing of a desired model. In addition, PDS combines mixed mode SPICE circuit simulation,

animated components and microprocessor models to facilitate co-simulation of complete


28

microcontroller based designs. For the first time ever, it is possible to develop and test such

designs before a physical prototype is constructed. This is possible because PDS can easily

interact with the designing of screen based indicators, such as, LED and LCD displays and

actuators, such as, switches and buttons. The simulation takes place in real time: a 1GMHz

Pentium III can simulate a basic 8051 system clocking at over 12MHz. PDS also provides

extensive debugging facilities including breakpoints, single stepping and variable display for

both assembly code and high level language source.

3.1.1 Overview of the Proteus Design Suite

Initially, starting the program that can be possible by clicking on the ISIS Professional v7.1 icon

from desktop of personal computer. Thus, starting interface is appeared according to the Fig. 3.1.

3.1.2 Circuit Construction and Assembly

Prior to circuit construction, it is necessary to identify first the required components in the

circuit. For example, in executing an 8-bit running light, the components needed are:

i. PIC16F877

ii. LED

iii. Resistor

iv. Capacitor

v. Power Supply Terminals / Grounding


29

Fig. 3.1: Overview of Proteus software.

3.1.3 PIC16F877A parameter setting

The PIC16F877A property panel can be similarly obtained by right clicking the PIC and

selecting “Edit Component”. The PIC parameters like oscillator frequency, program

configuration word and other properties should be appropriately supplied. The program code in

hex file should be loaded in the program file section. The summary of the entire procedure for

parameter setting is shown in Fig. 3.2.

3.1.4 Simulation

After defining all the various parameters in the PIC and the other components and also loading

the hex file in the controller, we can start the simulation by clicking the PLAY button on the

bottom panel of the PDS.


30

Fig.3.2: PIC parameter setting on Proteus.


31

3.2 Proteus Layout of MPCS

The MPCS layout is presented in the Proteus software that is shown in Fig.3.3

Fig.3.3: MPCS shown in Proteus.

3.3 MikroC programming tools

MikroC is a powerful, feature rich development tool for PIC microcontrollers. It is designed to

provide the customer with the easiest possible solution for developing application for embedded

system, without compromising performance or control. PIC is the most popular 8-bit chip in the

world, used in a wide variety of application, and C, prized for its efficiency, is the natural choice

for developing embedded systems. MikroC provides a successful match featuring highly

advanced IDE, ANCI compliant compiler, broad set of hardware libraries, comprehensive

documentation, and plenty of ready-to run examples.


32

3.3.1 Creating a new project

To create a new project in MikroC Pro for PIC, a new window must be opened that is shown in

Fig.3.4. Then, a new project wizard needs to be opened (see Fig. 3.5) and follow Fig. 3.6. Now,

define a project name according to Fig. 3.7 and select a folder on desktop to store the hex file

(see Fig. 3.8). At last, follow the final step of creating a new project wizard (Fig. 3.9).

Fig.3.4: New wizard of MikroC Pro for PIC Microcontroller

3.3.2 Coding template

Fig.3.10 shows the coding template where any program can be written. In this template, program

(or, coding) of MPCS has been written and it is successfully built in the project.


33

Fig.3.5: Creating a new project in MikroC Pro for PIC


34

Fig.3.6: Creating a new project wizard in MikroC Pro for PIC on process.

Fig.3.7: Defining a file name.


35

Fig.3.8: Select location to store hex file.

Fig.3.9: Final step of a new project wizard


36

Fig.3.10: Coding of MPCS and built in condition.

3.4 AT command

These commands are used to control MODEMs. AT is the abbreviation for Attention. These

commands come from Hayes commands that were used by the Hayes smart modems. The Hayes

commands started with AT to indicate the attention from the MODEM. The dial up and wireless

MODEMs (devices that involve machine to machine communication) need AT commands to

interact with a computer. These include the Hayes command set as a subset, along with other

extended AT commands.


37

AT commands with a GSM/GPRS MODEM or mobile phone can be used to access following

information and services:

1. Information and configuration pertaining to mobile device or MODEM and SIM card.

2. SMS services.

3. MMS services.

4. Fax services.

5. Data and Voice link over mobile network.

3.4.1 Types of AT command

There are four types of AT commands, which are presented in Fig. 3.11.

Fig.3.11: Classifications of AT commands

The detailed discussion about the four AT commands is stated below:

1. Test commands - used to check whether a command is supported or not by the

MODEM.

SYNTAX: AT<command name>=?

For example: ATD=?

2. Read command - used to get mobile phone or MODEM settings for an operation.

SYNTAX: AT<command name>?

For example: AT+CBC?


38

3. Set commands - used to modify mobile phone or MODEM settings for an operation.

SYNTAX: AT command name value1, value2, ,valueN

Some values in set commands can be optional.

4. Execution commands - used to carry out an operation.

SYNTAX: AT command name parameter1, parameter2 parameterN

The read commands are not available to get value of last parameter assigned in execution

commands because parameters of execution commands are not stored.

Some of SMS AT commands are given bellow:

Command Description

AT+CSMS Select message service.

AT+CPMS Preferred message storage

AT+CMGF Message format

AT+CSCA Service center address

AT+CSMP Set text mode parameter

AT+CSDH Show text mode parameter

AT+CSCB Select cell broadcast message type

AT+CSAS Save setting

AT+CRES Restore setting

AT+CMGW Write message to memory

AT+CMGR Read message

AT+CMGW Write message

3.5 Pseudo Code of MPCS

1. Initialization ()

a. Initialize LCD display

b. Initialize UART port of microcontroller PIC16F877A

c. Initialize EEPROM memory at 0X00


39

2. Define

a. Input Port at PORTA

b. Output LCD display Port at PORTB

c. PORTA as digital input

d. Devices at output SMS PORTD

e. Array to store messages

3. Generate Message (){

a. Check UART Data is ready

b. Send AT Command to Ready Message

c. If Message is there

4. Main () {

a. define

b. Call function Initialization ();

C.Display load status on LCD

c. GenearteMessage ();

d. If Received Call () ==1

i. Compare sent message string with the device defined strings

ii. PORTA = PORTA & 0b00001111;

if(PORTA==0b00000000) DTMF_Code = 0;

else if(PORTA==0b00001000) DTMF_Code = 1;










40

else DTMF_Code = 0;

END

}

3.6 Program Coding

// DTMF Based load control

// PIC 16F877A

//X_Tal: 8MHz

// LCD module connections

sbit LCD_RS at RB7_bit;

sbit LCD_EN at RB6_bit;

sbit LCD_D4 at RB5_bit;




sbit LCD_RS_Direction at TRISB7_bit;

sbit LCD_EN_Direction at TRISB6_bit;

sbit LCD_D4_Direction at TRISB5_bit;




// End LCD module connections

int DTMF_Code = 0;

int D_port1,D_port2;

shortold_status = 1;


41

void SMS_Int(void)

{

UART1_Write_Text("AT\r");

Delay_ms(500);

UART1_Write_Text("AT+cmgf=1\r");

Delay_ms(500);

UART1_Write_Text("AT+cmgs=");

UART1_Write((char)'"');

UART1_Write_Text("01716710375");

UART1_Write((char)'"');

UART1_Write((char)13);


Delay_ms(500);

}

char SMS[] = "Load1: ; Load2: ; Load3: ; Load4: .";

void main()

{

// I/O settings...

TRISA = 0xFF; // set all as input

TRISD = 0x00;// output settings

PORTD = 0x00;

ADCON0 = 0x00;

ADCON1 = 0x07; // set all digital i/o

CMCON = 0x07;// comparator off

Lcd_Init();

Lcd_Cmd(_LCD_CLEAR);

Lcd_Cmd(_LCD_CURSOR_OFF);

Delay_ms(100);

Lcd_Out(1,1,"Debashish Das");


42

Lcd_Out(2,1,"ID:052201P");

PORTD = 0x00;

Delay_ms(3000);

Lcd_Cmd(_LCD_CLEAR);

Lcd_Out(1,1,"L1:");

Lcd_Out(1,9,"L2:");

Lcd_Out(2,1,"L3:");

Lcd_Out(2,9,"L4:");

PORTD = 0x00;

UART1_Init(9600); //initialize UART at baud rate 9600

Delay_ms(100);

while(1)

{ // continuous program...

UART1_Write_Text("AT\r\n");

Delay_ms(500);

PORTA = PORTA & 0b00001111;

if(PORTA==0b00000000) DTMF_Code = 0;










else DTMF_Code = 0;

}


43

//char SMS[] = "Load1: ; Load2: ; Load3: ; Load4: .";

if(RD0_bit)

{

SMS[6] = 'O';

SMS[7] = 'N';

SMS[8] = ' ';

}

else

{

SMS[6] = 'O';

SMS[7] = 'F';

SMS[8] = 'F';

}

if(RD1_bit)

{

SMS[17] = 'O';

SMS[18] = 'N';

SMS[19] = ' ';

}

else

{

SMS[17] = 'O';

SMS[18] = 'F';

SMS[19] = 'F';

}


if(RD2_bit)

{

SMS[27] = 'O';

SMS[28] = 'N';


44

SMS[29] = ' ';

}

else

{

SMS[27] = 'O';

SMS[28] = 'F';

SMS[29] = 'F';

}


if(RD3_bit)

{

SMS[38] = 'O';

SMS[39] = 'N';

SMS[40] = ' ';

}

else

{

SMS[38] = 'O';

SMS[39] = 'F';

SMS[40] = 'F';

}

D_port1 = PORTD & 0b00001111;

if(D_port1 != D_port2)

{

//Generation of SMS

SMS_Int(void);

Delay_ms(100);

UART1_Write_Text(SMS);

UART1_Write((char)26); //send Control + Z



45


}

// for Load 1

if(DTMF_Code==1)

{

RD0_bit = 1; // turn load 1 on

Lcd_Out(1,4,"ON ");

Delay_ms(1000);

}

else if(DTMF_Code==2)

{

RD0_bit = 0; // turn load 1 off

Lcd_Out(1,4,"OFF");

Delay_ms(1000);

}

// for Load 2


{

RD1_bit = 1;

Lcd_Out(1,12,"ON ");

Delay_ms(1000);

}


{

RD1_bit = 0;

Lcd_Out(1,12,"OFF");

Delay_ms(1000);

}

// for Load 3



46

{

RD2_bit = 1;

Lcd_Out(2,4,"ON ");

Delay_ms(1000);

}


{

RD2_bit = 0;

Lcd_Out(2,4,"OFF");

Delay_ms(1000);

}

// for Load 4


{

RD3_bit = 1;

Lcd_Out(2,12,"ON ");

Delay_ms(1000);

}


{

RD3_bit = 0;

Lcd_Out(2,12,"OFF");

Delay_ms(1000);

}

else

{

PORTD = PORTD;

Delay_ms(1000);

}


47

if(DTMF_Code == 9)

{

//send SMS

SMS_Int(void);

Delay_ms(100);

UART1_Write_Text(SMS);

Delay_ms(3000);

UART1_Write((char)26);//send Control + Z



DTMF_Code = 0;

}

D_port2 = D_port1;

Delay_ms(1000);

}//while

}//void

Chapter 4: Experimental studies

48

Chapter 4

Experimental studies

This chapter presents the detailed experimental studies of MCPS including the observation of

current load status.

4.1 Experimental studies

In this section, it is discussed about the physical construction and operations of the proposed

system. There is DTMF circuit that receives signal from user’s mobile and send data into

microcontroller. Microcontroller read the information and takes necessary action to control the

loads. A GSM modem is used that sends message to user’s mobile unit about the current status

of the remote loads. However, to implement the whole system, part by part implementation was

observed first. As an experimental study, the entire observation is divided into three ways: (i)

implementation and observation of DTMF circuit, (ii) controlling and displaying loads using

mobile phone, (iii) final implementation of MPCS. For more clarification, the total observation

is discussed below:

4.1.1 Implementation and observation of DTMF circuit

In order to implement the entire system, initially the DTMF circuit has been implemented in a

small breadboard as an experimental basis. In this case, the four loads are replaced by four

LEDs nominated by L1, L2, L3 and L4. In Fig. 4.1, it is found that whenever user’s mobile


49

made contact with remote mobile, then if the keypad is pressed by “1” from the user’s mobile,

the Load1 (assigned by L1) is ON. On the other hand, Load1 is OFF if the keypad is pressed by

“2”. Similar tasks are performed sequentially for the rest of Loads (i.e., L2, L3, and L4). These

phenomena have been performed according to the DTMF test data sheet mentioned in Table 4.1.

Fig.4.1: Implementation and observation of DTMF circuit.

4.1.2 Controlling and displaying loads using mobile phone

The circuit was made for controlling loads and displaying their current status in the bread board

as an experimental basis, which has been presented in Fig. 4.2. In this circuit, the outputs


50

obtained from DTMF circuit are fed to the microcontroller inputs. Then, microcontroller

manipulates those signals and displays in the LCD about their current status.

Table 4.1: DTMF Test Datasheet

Keypad

pressed

button

number

DTMF CKT

Output, Q1

DTMF CKT

Output, Q2

DTMF CKT

Output, Q3

DTMF CKT

Output, Q4

Desired

Load Load Status

1 0 0 0 1 L1 ON

2 0 0 1 0 L1 OFF

3 0 0 1 1 L2 ON

4 0 1 0 0 L2 OFF

5 0 1 0 1 L3 ON

6 0 1 1 0 L3 OFF

7 0 1 1 1 L4 ON

8 1 0 0 0 L4 OFF

Fig. 4.2: Controlling and displaying loads using mobile phone.


51

Fig. 4.3: Final implementation of MPCS


52

Fig. 4.4: Observation of current load status


53

Table 4.2: Results of MPCS

Time requirement for operating the loads in case of MPCS using Hardware setup and Software

simulation.

Digit

From

Mobile

Keypad

Q1Q2Q3Q4 Desired

Load

Status of Loads Required

Time by

Hardware

Setup

(Second)

Required

Time by

Software

Simulation

(Second)

Load-

1

Load-

2

Load-

3

Load-

4

1 0001 Load-1 ON OFF OFF OFF 5 1.0

2 0010 Load-1 OFF OFF OFF OFF 5 1.0

3 0011 Load-2 OFF ON OFF OFF 5 1.0


5 0101 Load-3 OFF OFF ON OFF 4.5 1.0


7 0111 Load-4 OFF OFF OFF ON 5 1.0


From the above table, it can be observed that, to operate an individual loads among the four, the

required time for MPCS in hardware setup is higher than that of proteus software simulations.

The reason is that, electrical devices need an amount of time to convey the signal from one

place another place. Moreover, they have some temperature effect in resistivity, whereas,

software simulation is totally out of such constraints.

4.1.3 Final Implementation of MPCS


54

Before going to the final implementations, two experiments have been conducted successfully

mentioned in Subsections 4.1.2 and 4.1.3. After that, finally, the proposed system-MPCS

implemented in a Vero board presented in Fig. 4.4. Here, four electrical lamps were used as the

remote electrical loads.

4.1.4Observation of current load status

Fig.4.4 shows a complete prototype version of MPCS (Mobile Phone based Control System).

From this prototype version, the current load status from LCD display can be observed.

Moreover, we can see the current status of different electrical loads by auto generated SMS

shown in Fig.4.5.

Chapter 5: Conclusion

55

Chapter 5

Conclusion

5.1 Conclusion

In this report, a mobile phone based control system (MPCS) has been developed in order

to communicate with the remote loads automatically. This project uses the DTMF

technology involving GSM modem, mobile key pad, electrical relay, and so on.

Particularly, DTMF generates the signal through the mobile key pad, which is very

efficient for very long distance data transmission. The entire project has been formulated

by Microcontroller with its program coding.

In combination of GSM modem with DTMF, microcontroller can easily provide the

present status of the remote electrical loads. Therefore, anyone can get the current status

about the remote loads individually whether it being ON/OFF mode from the sender end.

Thus, using the proper handling of offices or household electrical appliances, where

people often used to forget to switch off, energy saving can be possible.

No expert human is required at the remote places to be made contact with the sender end.

Further extension for the number of remote electrical loads can be possible in MPCS any

time. It can be noted that, our project MPCS has a very good future for our country’s

respect whether it could be established commercially at the industrial areas. Thus, our

Chapter 5: Conclusion

56

industrial management will be more dynamic as well as the production cost will be

reduced.

According to our knowledge, this project is not only developed first in DUET, but also a

promising work in the respect of Bangladesh also. In this work, I have successfully

implemented a prototype multiple load controlling system by mobile phone, where a LCD

display was used to observe the present status of the remote loads whether it is in

ON/OFF mode.

5.2 Recommendation for future work

For future work, hopefully 3.5G network will be used for data visualization in operator’s

mobile and after implementation the status of loads’ physical condition can be known.

57

References

[1] M.M. Rashid. “ Design and Development of a Universal Three-Phase Control Module

Operated by Cell Phone,” M. Engg. Project Report, EEE dept. of DUET,2009.

[2] T. Begum, “ Design and Development of Activation and Monitoring of Home

Automation System via SMS though Microcontroller,” M.Sc. Engg. Thesis Report, EEE

dept. of DUET, 2010.

[3] C.K Das, M. Sanaullah, H.M.G Sarawor and M. M. Hasan, “ Development of a Cell

Phone based Remote Control System : an effective Switching System for Home and

Office Appliances,”International Journal of Electrical and Computer SciencesIJECS-

IJENS, vol. 9, no. 10, 2009

[4] Coskun and H. Ardam, “ A Remote Controller for Home and Office Appliances by

Telephone,” IEEE Transaction on Consumer Electronics, vol. 44, no. 4, pp. 1291-1297,

November 1998.

[5] E. ong, “A Phone based Remote Controller for Home and Office Automation,” IEEE

Transaction on Consumer Electronics, vol. 40, no. 1, pp. 28-33, February 1995.

[6] M Rahman, A. H. M. Z. Karim, F. Khan,G Matin, “Microcontroller Based Home

Security and Load Controlling Using GSM Technology,” International Journal of

Computer Network and Information Security, vol. 4, pp. 29-36,2015.

[7] M. Amanullah, “ Microcontroller Based Reprogrammable Digital Door Lock Security

System by Using Keypad & GSM Technology,” IQSR Journal of Electrical and

Electronic Engineering, vol. 4, issue 6, pp. 38-42, 2013.

[8] Sakti Bajaj Sandep, “Speed regulation DC drive using cell communication,”

International Journal of Soft Computing and Engineering (IJSCE), vol. 3, issue 1, March

2013.

[9] http://www.sim.com

http://www.sim.com/

58

[10] M. Ahmed, Faruki H, S. Ahmed and M.S. Harsoliya “ 3G based industrial automation

using GSM communication ,” International Journal of Research in Environmental science

and Technology, vol. 1, issue 2, pp. 16-23,2011

[11] http://www.ti.com/crystal_osci

[12] A tutorial on Microcontroller: Microchip 16F87XA Datasheet, Microchip Tech Inc, 2003.

[13] http://www.mikroe.com

http://www.ti.com/crystal_osci

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