PROJECT REPORT ON
“INTELLIGENT LETTER BOX”
BHARAVAD MERABHAI K. 140160109006
CHAUDHARI MAYANKKUMAR R. 140160109011
DARJI AKSHAYKUMAR G. 140160109016
SHAH VISHAL M.
PROF. GAJENDRASINH RATHORE
In Fulfilment for the award of the degree
BACHELOR OF ENGINEERING
Government Engineering College, Modasa
Gujarat technological university, Ahmedabad
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CHAPTER 1: INTRODUCTION 07
1.1 Background and problem summary 07
1.2 Project detail 08
1.2.1 AIM and Objective 08
1.3 Literature review 09
1.4 Plan of their work 12
1.5 Material used 13
1.6 Software required 21
CHAPTER 2: DESIGN 23
2.1 Design methodology and implementation
CHAPTER 3: IMPLEMENTATION 27
3.1 Basic block diagram 27
3.1.1 Diagram for sensing circuit 27
3.1.2 Diagram For locking circuit 28
3.2 Circuit diagram 29
3.3 Circuit connection 30
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3.4 Programming 30
3.5 Making letter box 39
3.6 Testing 41
3.6.1 Before imply in letter box 41
3.6.2 After imply in letter box 44
CHAPTER 4: SUMMARY 47
4.1 Advantages 47
4.2 Scope of future work 47
4.3 Feature 48
4.4 Limitation 48
4.5 Conclusion 49
Business model canvas 51
PDE Form 54
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It is our great pleasure to acknowledge the contribution and assistance of a few individuals to
this effort. We acknowledge here to our debt to those who have contributed significantly to this
We are indebted to Prof. RAJ KAPADIYA for motivating us and fostering a feeling of
belongingness towards our work. We are also thankful to our project guide Prof.
GAJENDRASINH RATHORE for helping us at each step of our project. Their helpful
solutions and comments enriched by his experience for the betterment of the project.
Our thanks go to all the staff members of Department of Electrical Engineering.
Finally, we would like to thank everyone who directly or indirectly helped us in the project.
With thanks to all.
Bharavad Merabhai K. 140160109006
Chaudhari Mayankkumar R. 140160109011
Darji Akshaykumar G. 140160109016
Shah Vishal M. 140160109096
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GOVERNMENT ENGINEERING COLLEGE, MODASA
This is to certify that the dissertation entitled “INTELLIGENT
LETTERBOX” has been carried out by BHARAVAD MERABHAI K.
(140160109006), CHAUDHARI MAYANKKUMAR R. (140160109011),
DARJI AKSHAYKUMAR G. (140160109016), SHAH VISHAL M.
(140160109096) under my guidance in fulfillment of the degree of Bachelor
of Engineering in Electrical Engineering (8th Semester) of Gujarat
Technological University, Ahmedabad during the academic year 2017-18.
Prof. Gajendrasinh Rathore
Head of Department:
Prof. Jyoti R. Iyer
Sign of External Exam
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? in nowadays correspondence is not use more but there many important documents,
courier and parcels are come at home through post man or courier man, so many
people face problem to deliveries of post and parcels, so here we made a one smart
letterbox, which start counting and notify you by a text message on your mobile
phone when anyone insert a letter, courier or any parcels in your letterbox. Letterbox
has smart technology. It has GSM Module which can send message to owner also
there LCD display which can show status of letterbox, and also time and date is saved
by RTC circuit. Its design to save your time from going to the letter box to check if
there are letter inside or not. If anyone insert letter than message will come on your
mobile. There also one electronic lock on door of letterbox, which is pre-set by one
code, without this code lock will never open. So there one best locking system is
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CHAPTER 1:- INTRODUCTION
1.1 Background and problem summary:-
? Today’s people have very busy routine for their work, job and business. So they don't
have a time and mostly they not present at their home. So when any important
document, letter, parcels or couriers are comes on their address, then there no any
person at home for take it. So there people used simple letterboxes at their home, as
shown in below picture.
Fig. 1.1(a) – Simple letterbox
? But their many problems are faced by people in simple letter boxes, we studied about
all problems and try to solve it in our invention. Different problems are describe below.
? In many parts of different country, especially rural areas, mailbox or letterboxes are
remotely located with respect to the residence of the person to whom the mailbox
belongs. Often, this distance can be has much as several hundred yards or more, making
it necessary to travel outside, often in inclement weather, in order to determine if mail
or letter is present.
? There is no any safety or protection for our mail, document, letter or newspaper and
also many people lost their key of letter box so there are problems faced.
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? When letter or any parcels are delivered to boxes, it is impossible for the owner of the
box to know whether their letter or any object in box. In addition, if a large package is
expected there is no way of knowing when the package is actually in a designated box.
Therefore, there is a need for a means to notify a mailbox owner, remotely, of the
presence of mail or letter in the owner’s box.
? So we try to solve above all problems in our invention. We try to make smart letterbox
which have smart technology and best security system.
1.2 Project detail:-
1.2.1 AIM and Objective of the project:-
? The main purpose of this project is to get connected owner with his/her letterbox. The
owner can get text message with delivery time & date when postman delivers, and also
it’s provide best security to your document with best locking system.
? Our project contains IR sensor for sense the letter, RTC for note time and date, Arduino
for controlling, GSM module for wireless communication, LCD display for status and
locking system for best security. The project is related to the letter and couriers.
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220.127.116.11 How project work:-
? When any letter get inserted into the letter box the pair of IR sensor sense the letter and
send this signal to the Arduino. Arduino control the whole system, when IR sensor
sense the letter at same time RTC notice delivery time and date, it send the signal to the
Arduino. LCD display is attached to the letter box. LCD display receive data from the
Arduino and show delivery dates, time and no. of letter. GSM module receive a signal
from the Arduino. GSM module send the text message with delivery time and date to
the owner. So that’s owner always connected with his/her letter box.
1.2.1 Where the project will be used: –
? We can use this intelligent letterbox in below places:
3. Police stations,
5. Government places and
6. Personal use for people etc.
1.3 Literature review:-
? To find the project subject we searched many literatures, web-sites, magazines etc. We
referred electronics for you magazine for getting new idea. First we got idea of
electronic letterbox from electronics for you magazine. It’s very simple project and
design, after that we start searched about, how to make it very effectively and smart.
We thought that what we can do new in this design.
? We want to make one smart letterbox, it sense the letter when anyone insert a letter
inside it and notify to owner by message on mobile. It’s also provide electronic locking
system. It has one code. Door will never open without code. So we started to search
best sensing systems, wireless message system and best locking system.
? For that we searched many website on google and also searched research papers. From
all of that we noted useful information related to our invention.
? We also searched many patent on google patent like, how to sense letter inside the letter
box, how get notify message when anyone insert letter inside letterbox, how make smart
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letterbox etc. From all above searches we get many useful information and data. All
patents are say something new.
? From patent and sites, we able to know about sensing circuit. To sense a letter inside
letterbox, IR sensor is useful. It can sense letter when anyone insert it in letterbox. For
getting message on the mobile there GSM module and Arduino useful. In many patent
mostly microcontroller used but we choose Arduino instead of microcontroller.
Arduino is the main part of the system. Arduino is connected with all components of
circuit. Arduino can control and manage whole system so we say the Arduino is brain
of system. After sense letter sensor gives command to Arduino and through Arduino
and GSM module there message is send to owner.
? All this information is very useful for us to make circuit for letterbox. There also design
of letterbox is important after making circuit how to set all components in one box is
challenge for us. So for that we also studied many patent and design web-sites.
Literature on detecting and signaling the presence of objects in a closed
container and mailbox.
Patent no: – US5377906A
? Accordingly, one object of the present invention is to provide a device for detecting and
signaling the presence of an object in a remotely located container which can be simply
installed without modification to the container. A further object of the present invention
is to provide a device for detecting and signaling the presence of an object in a remotely
located container which does not require a separate receiver for the signal produced. A
further object of the present invention is to provide a device for detecting and signaling
the presence of an object in a remotely located container which provides no false
Literature on Mailbox status system and method.
Patent no: – US6995671B2
? One aspect of the present invention provides a method for notifying an electronic
address of the presence of physical mail in a designated mailbox. The presence of at
least one piece of mail in the mailbox is detected and an electronic notification is
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transmitted to the address indicating the presence of the at least one piece of mail. The
term mail is used herein to mean letters as well as parcels. Another aspect of the present
invention provides a method for managing a mailbox. The presence and absence of at
least one physical mail piece in the mailbox is detected electronically, generating a
detection event. The detection event is transmitted to an electronic address.
Literature on Smart newspaper boxes System.
Patent no: – CN105167547B
? The present invention provides an intelligent control system and method for newspaper
boxes. Newspaper boxes intelligent system of the invention comprises a single-chip
system, the infrared sensing system, a radio frequency identification system lock, alarm
system buzzer, LED display system, an independent power supply system, and GSM
communication system. Advantage of the invention is to automatically send text
messages to notify the user when the system detects a mail alert will immediately give
the user, timely and efficient user to take letters, save time and improve efficiency;
RFID implement user authentication, the system newspaper boxes exclusive use of type
design principles, each newspaper boxes corresponding to a radio frequency card,
improves security letters, greatly reducing the potential for loss of mail.
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1.4 Plan of their work:-
on of need
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1.5 Materials used:-
1.5.1. Pair IR sensor:-
? An infrared (IR) sensor is used to detect obstacles in front of the robot or to differentiate
between colors depending on the configuration of the sensor.
? Infrared Obstacle Sensor Module has built in IR transmitter and IR receiver that sends
out IR energy and looks for reflected IR energy to detect presence of any obstacle in
front of the sensor module. The module has on board potentiometer that lets user adjust
detection range. The sensor has very good and stable response even in ambient light or
in complete darkness.
Operating voltage: 3.0V – 5.0V
Detection range: 2cm – 30cm (Adjustable using potentiometer)
Current consumption: at 3.3V : ~23 mA, at 5.0V: ~43 mA
Active output level: Output Low logic level when obstacle is detected
On board Obstacle Detection LED indicator
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18.104.22.168 Working Principle of IR Obstacle Sensor:-
? An IR sensor consists of an IR LED and an IR photodiode; together they are called as
Photo-Coupler or opto-Coupler. As said before, the Infrared Obstacle Sensor has built-
in IR transmitter and IR receiver. Infrared Transmitter is a light emitting diode (LED)
which emits infrared radiations. Hence, they are called IR LED’s. Even though an IR
LED looks like a normal LED, the radiation emitted by it is invisible to the human eye.
Infrared receivers are also called as infrared sensor as they detect the radiation from an
IR transmitter. IR receivers come in the form of photodiodes and phototransistors.
Infrared Photodiodes are different from normal photo diodes as they detect only
infrared radiation. When the IR transmitter emits radiation, it reaches the object and
some of the radiation reflects back to the IR receiver. Based on the intensity of the
reception by the IR receiver, the output of the sensor is defined.
1.5.2 Real time clock (DS1307):-
? Real time clocks (RTC), as the name recommends are clock modules. The DS1307 real
time clock IC is an 8 pin device using an I2C interface.
? The acronym RTC stands for Real Time Clock, i.e. a Real Time Clock (RTC). This
module has 56 bytes of non-volatile memory available for use, is able to store and
provide date of complete information as day of week, day, month, year and beyond of
course, the functions of hours, minutes and seconds, the formats of 12 or 24 hours.
Month with less than 31 days and leap years are automatically adjusted. This tiny RTC
module is based on the clock chips DS1307 which supports the I2C protocol. It uses a
Lithium cell which ensures that the data is preserved even without an external power,
and is automatically activated in case of power failure in the module.
DS1307 I2C real time clock chip (RTC)
Fully charged, can power DS1307 module for 1 year
DS1307 can provide clock for microcontroller
I2C devices can be cascaded
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Fig. 1.2.5(b) REAL TIME CLOCK
Fig. 1.5(c) Pin diagram of RTC
22.214.171.124.2 Pin description:-
BAT – Battery voltage. To monitor the battery voltage or not connected
GND – Ground
VCC – 5V supply. Power the module and charge the battery
SDA – I2C data for the RTC
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SCL – I2C clock for the RTC
DS – DS 18B20 Temperature Sensor output
SQ – Square wave output. Normally not used.
1.5.3 LCD Display (16*2):-
? Liquid Crystal Display (LCD) is a flat display used in digital watches, cameras and
many portable computers. LCD displays utilize two sheets of polarizing material with
a liquid crystal solution between them. An electric current passed through the liquid
causes the crystals to align so that light cannot pass through them. Each crystal,
therefore, is like a shutter, either allowing light to pass through or blocking the light.
LCD’s consume much less power than LED and gas-display displays because they work
on the principle of blocking light rather than emitting it. LCD’s are used in flat screen
TV’s, smartphones, computer monitors, digital watches, etc.
? The LCD can be made in different sizes such as, 8×1, 8×2, 10×2, 16×1, 16×2, 16×4,
20×2, 20×4, 24×2, 30x etc. For example, take LCD 16×2 which means it can display
16 characters per line and there are 2 such lines. All these LCD’s performs the same
functions such as display characters, numbers, special characters ASCII characters etc.
Hence their programming is also the same since they all comes with same 14 pins (0-
13) or 16 pins (0 to 15).
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126.96.36.199 Pin description of LCD:-
? All LCDs have 14 or 16 pins. Let’s see them in the following.
GND or VSS : Ground or 0V
VCC or VDD : supply voltage 5V
VEE : contrast adjustment through a variable resistor
RS: Register select. Generally, every LCD has two types of registers
namely Command Register and Data Register. When RS=0 or low,
command register is selected and when RS=1 or high, Data register is
R/W: Read/Write. When RW=1, data is read from LCD and when RW=0,
writes the data to LCD.
EN: Enable. Sends data to data pins when a high to low pulse is given.
Eight Data pins (DB0 to DB7): this 8-data pins carries 8-bit data or
command from an external unit such as micro controller.
Led+: Back light of the LCD which should be connected to VCC or 5V.
Led: Back light of the LCD which should be connected to GND or 0V.
1.5.4 Arduino UNO:-
? Arduino Uno is a microcontroller board based on the ATmega328P. It has 14
digital input/output pins (of which 6 can be used as PWM outputs), 6 Analog
inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP
header and a reset button. It contains everything needed to support the
microcontroller; simply connect it to a computer with a USB cable or power it
with an AC-to-DC adapter or battery to get started. You can tinker with your
UNO without worrying too much about doing something wrong, worst case
scenario you can replace the chip for a few dollars and start over again.
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Fig. 1.5.(e) Arduino UNO
188.8.131.52 Technical Specification:-
Microcontroller : ATmega328P
Operating voltage : 5V
Input voltage (recommended) : 7 – 12V
Input voltage (limit) : 6 – 20V
Digital I/O pins : 14
PWM Digital I/O pins : 6
Analog input pins : 6
DC current per I/O pin : 20mA
DC current for 3.3V pin : 50mA
Flash memory : 32kb of which 0.5KB used by bootloader
SRAM : 2KB(ATmega328P)
EEPROM : 1KB(ATmega328P)
Clock speed : 16MHz
LED_BUILTIN : 13
Length : 68.6 mm
Width : 53.4 mm
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Weight : 25g
184.108.40.206 Pin configuration:-
? USB: The USB port is used to power the board from the computer’s USB port and also
to transfer the program code from computer into the Arduino microcontroller. External
Power: It is used to power the board it the USB connector is not used. An AC adapter
(9 volts, 2.1mm barrel tip, and center positive) could be used for providing external
power. If there is no power at the power socket, then the Arduino will use power form
the USB socket. But it is safe to have power at both the power socket and USB socket.
? Digital Pins (I/O): The Arduino Uno has 14 digital pins (0 to 13) of which the 6 are
PWM (~) this pins can be either inputs or outputs. But we need to mention it in the
Arduino sketch(Arduino programming) The PWM(Pulse Width Modulated) pins acts
as normal digital pins and also used to control some functions Say for example, control
the dimming of LED and control the direction of servo motor. Both digital inputs and
digital outputs can read one of the two values either HIGH or LOW.
Fig. 1.5(f) Pin configuration of Arduino
? Analog Pins: The Analog pins (0 to 5) acts as inputs which is used to read the voltage
in analog sensors such as temperature sensor gas sensor, etc. Unlike digital pins which
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can only read one of the two values (HIGH or LOW, the analog inputs can measure
1024 different voltage levels.
? ATmega Microcontroller: The Arduino uses ATmega328 microcontroller. It is a
single chip microcontroller created by Atmel. This chip works well with Arduino IDE
lf damaged, this controller can be easily replaced. The Atmega328 has 32 KB of flash
memory for storing code of which 0.5 KB is used for the boot loader).It has also 2 KB
of SRAM and 1 KB of EEPROM.
? 3.3V Pin: A 3.3 volt supply generated by the on-board regulator. Maximum current
draw is 50 mA.
? 5V Pin: The regulated power supply used to power the microcontroller and other
components on the board. This can come either from an on-board regulator, or be
supplied by USB or another regulated 5V Supply.
? Reset Button: It is used to reset the microcontroller. Pushing this button will
temporally connect the reset pin to ground and restart any code that is loaded on the
1.5.5 GSM Module(SIM 900A):-
Fig. 1.5(9) GSM SIM 900A
? GSM module is used for sending notification or message to the owner, when anyone
insert a letter into letter box. It’s connected with Arduino circuit, when Arduino get
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command from sensor circuit of post deliveries then Arduino give command to GSM
module for sending notification to the owner.
? GSM/GPRS Modem-RS232 is built with Dual Band GSM/GPRS engine- SIM900A,
works on frequencies 900/ 1800 MHz. The Modem is coming with RS232 interface,
which allows you connect PC as well as microcontroller with RS232 Chip(MAX232).
The baud rate is configurable from 9600-115200 through AT command. The
GSM/GPRS Modem is having internal TCP/IP stack to enable you to connect with
internet via GPRS. It is suitable for SMS, Voice as well as DATA transfer application
in M2M interface. The onboard Regulated Power supply allows you to connect wide
range unregulated power supply. Using this modem, you can make audio calls, SMS,
Read SMS, attend the incoming calls and internet ect through simple AT commands.
220.127.116.11 Feature of GSM module:-
Dual-Band GSM/GPRS 900/ 1800 MHz
RS232 interface for direct communication with computer or MCU kit
Configurable baud rate
Power controlled using 29302WU IC.
Enable with MIC and Speaker socket.
With slid in SIM card tray.
With Stub antenna and SMA connector
Input Voltage: 12V DC.
1.6 Software required:-
1.6.1 Arduino IDE:-
? A program for Arduino may be written in any programming language for a compiler
that produces binary machine code for the target processor. Atmel provides a
development environment for their microcontrollers, AVR Studio and the newer Atmel
? The Arduino project provides the Arduino integrated development environment (IDE),
which is a cross-platform application written in the programming language Java. It
originated from the IDE for the languages Processing and Wiring. It includes a code
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editor with features such as text cutting and pasting, searching and replacing text,
automatic indenting, brace matching, and syntax highlighting, and provides simple one-
click mechanisms to compile and upload programs to an Arduino board. It also contains
a message area, a text console, a toolbar with buttons for common functions and a
hierarchy of operation menus.
? A program written with the IDE for Arduino is called a sketch Sketches are saved on
the development computer as text files with the file extension .ino. Arduino Software
(IDE) pre-1.0 saved sketches with the extension.
? The Arduino IDE supports the languages C and C++ using special rules of code
structuring. The Arduino IDE supplies a software library from the Wiring project,
which provides many common input and output procedures. User-written code only
requires two basic functions, for starting the sketch and the main program loop, that are
compiled and linked with a program stub main() into an executable cyclic
executive program with the GNU tool chain, also included with the IDE distribution.
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CHAPTER 2:- DESIGN
2.1 Design methodology and implementation strategy:-
? First of all there we want to make something new and better which can helpful for
people and society. So, we searched that type invention which is interacted with society
and people. After searched many things, we thought to work on letterbox, because
letterbox is simple one thing which can interacted with all people of society. Now there
we consider many parameter for invention, like environment, activities, users etc. These
all of included into AEIOU Summary canvas.
Fig 2(a) AEIOU Summary
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? After observation of AEIOU summary, we start to observation or analysis on how this
invention can interact with people and how people are feels for that. So we did some
activities related that and noted whats empathy from people on this invention. There
many people faced problem related to post deliveries. Many people have experience on
that, so we noted empathy of users and what people can think about our idea. We also
wrote stories on that in empathy mapping canvas.
Fig 2(b) Empathy mapping canvas
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? After AEIOU and Empathy mapping design now we actually started work on project.
How to make design, which components are use, what activities are done by invention,
which people can interacted with it, what’s situation, location is better for that etc. now
we started to design letter box. For better, compact, smart and economical design there
selection of components is very important, so we first list out the components. Also
there cost is important because medium people consider cost first for all things, so we
select economical tools. Selection of tools/components/ objects for invention is most
important for us. We list out that and also indicate it’s in ideation canvas.
Fig 2 (C) Ideation canvas
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? After decide components and design of letterbox, now we decide purpose of our work,
how it’s connect with people and after all of that we made complete design and
development of product. Now we start to get feedback from people, how they feel and
how it can be useful for them. Customer feedback is most important for any inventor
or shop keeper, because any inventor or owner can worked based on customer feedback.
Without customer feedback, one cannot get actual idea for how to work. So we started
to get feedback from people, there many people give good feedback and also many
people give bad feedback. Upon that base we try to modify or add something new in
product. So we reject some old design and add something new as per customer’s
feedback. These all parameters are indicates into the Product Development Canvas.
Fig 2 (D) Product development canvas
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CHAPTER 3:- IMPLEMENTATION
During 7th sem we did only theory work but now in 8th sem there in part of implementation
we make working model of project. To make working model of projet there very much work,
design are required.
In 7th sem we made simple block diagram for sensing circuit and locking circuit and also we
made circuit diagram and pin connection of our project. Which is shown below.
3.1 Basic block diagram:-
3.1.1 Diagram for sensing circuit:-
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3.1.2 Diagram For locking circuit:-
? Basic block diagram of electronic lock is shown below. As shown in diagram there
keypad is connected to Arduino and Arduino is connected to servo motor. When anyone
insert code or password through keypad then Arduino check it, if it is right then servo
motor start to run and through servo motor door lock will open.
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3.2 CIRCUIT DIAGRAM:
Fig. 3.2(a) Circuit Diagram
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3.3 CIRCUIT CONNECTION:
It is important to make circuit connection. In this part we connect all components with each
other as our requirement. We do circuit connection as per our circuit diagram. Arduino
connect with RTC, GSM Module SIM 900A, LCD Display, and IR Sensor. As per
connection some snapshots are catchup by us which are shown below.
Fig. 3.3(a) Circuit Connection
Before making completely working module there is important to make rough connection and
also important to do some tests on it and as part of it we made rough connection and also
Programming is most important things in project of Arduino and Microcontroller.
Programming is like a soul of hardware connection. Without it any component do not work.
In our project we use Arduino uno R3 model, it is a one type of controller. Which is control
all components of our project. Its give command to other circuit as per programming.
Program of Arduino is built in Arduino IDE software.
In our project we want work like, when any one insert letter inside letter box then IR sensor
sense it and at that time message is send to owner’s mobile phone and also time and date of
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delivery is save in memory of Arduino and also it declare on LCD Display. For that we write
one Arduino Program and it’s shown below.
SoftwareSerial mySerial(10, 11); // RX, TX
#define sensor 2
#define indication 13
int leter, year1, year2;
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