CONTENTS

CHAPTER NUMBER TITLE PAGE NO

LIST OF FIGURES 6

ABSTRACT 7

1 INTRODUCTION 8

2 LITERATURE SURVEY 10

3 PROBLEM DEFINITION 13
4
4.1 BLOCK DIAGRAM & CIRCUIT 15
DIAGRAM
4.2 FLOW CHART 17

4.3 HARDWARE DESCRIPTION 17

4.4 SYSTEM SAFETY AND 23

RELIABILTY
4.5 IOT 27

4.6 EMBEDDED DEVICES 29

4.7 EMBEDDED SYSTEM 30

SOFTWARE
4.8 NODE MCU 30

4.9 RFID TECHNOLOGY 32

5 RESULTS AND DISCUSSION 36

6 SUMMARY AND CONCLUSION 38
REFERENCES 40

v
 Abstract:
Conventional billing systems used in the supermarket
nowadays are a big hassle for the customers as it creates a long
waiting time for payment of the products purchased. To provide
a solution for the above problem, we have designed an
application called Smart Shopping Cart using IoT which can
eliminate queues for billing throughout the supermarket. Using
the application, we scan the products and then put them inside
a Smart cart which is designed using Node MCU, and LCD to
display the total price of the items in the cart. To make it more
feasible the bill is also made available on the web server that
makes it easy for the customer to check the list of items added
and so they can manage the purchase.

vii
 Chapter 1

Introduction:

In our day-to-day life, we see that the use of computing

technology and innovative applications have increased rapidly.
Many people are connected to this digital world through their
smartphones and laptops because of the highspeed internet
connectivity, user-friendly interface, and personalized
recommendation. This has made things simpler and easier.

The new technology such as social media has given the

users a better and broader perspective of many items and
information about various products in their daily life and ensures
that they are of the best quality. As our cities are overpopulated,
the diversity of wants and needs of the people are also huge. As
a result, many people prefer to go to malls and supermarkets to
buy different varieties of commodities. The major drawback here
is the people coming to shopping malls and supermarkets are
huge in number, resulting in large queues for billing. Customers
have to wait for a long time in a queue for scanning their items
and paying the bill.

1
 An automated smart shopping system is formed by
introducing the concept of IoT to connect all items in the grocery
shop. In this system, an inexpensive RF-ID tag is embedded
within each product. When the product is placed into a smart
cart, the product detail is automatically read by the cart equipped
with an RF-ID reader. Hence, billing is made from the shopping
cart itself preventing customers from waiting in a long queue at
checkout. If any item is not scanned due to tampered bar code,
we can identify that based on weight at last. Thus, inventory
management becomes easier.
This system makes both the customer and supermarket
employee’s work easier by reducing the time it actually takes
while using the old method of billing i.e manual billing
technique.

2
 Chapter 2

Literature survey:
Bipin Kumar Yadav (2020); In retail stores, most of the
people spend more time in billing queue than the time he spends
choosing the items due to long queue in rush time. The average
time that customers of any retail store have to spend in the billing
queues has a direct influence on the quality analysis of services.
Thus, it is important to think about different ways to reduce the
waiting time in a queue in real time scenario. We propose a cart
system that distributes the whole billing queue into smaller
individual units so that no one has to wait for the billing process
at point of sales (PoS) for specific items. This device uses radio-
frequency identification (RFID) technology to scan each product.
A passive RFID sticker tag is attached with all the products. The
sticker tag contains information including name and price of the
product. The device includes a 13.56 MHz RFID reader/writer
module that reads RFID stickers attached to the products. In this
covid-19 alarmed situation, this distributed cart system also
helps people to maintain social distance avoiding long queues .
T Sarala; It is wireless techniques along with one more
communication technology has helped in making electronic
commerece very popular.In this paper we discuss on innovative
concept of “Smart Electronic shopping Trolley used in
commercial complex which many individual retail stores”.The
main purpose here is to assist a person in shopping to reduce
time while purchasing a products.Electonic trolley is fitted out
with Barcode reader that scanes the identification of outcome
and internet connection with shop's server.It is also consists of
LCD exhibits that notify the number of items and total amount to
customers and Barcode scanner identifies the outcome and

3
updates the bill.Swiping machine will be provided to recompense
the bill through credit/debit cards. In this paper,we report the
performance or administraion of reliable and more efficiency
smart trolley shopping using WSN such a trolley is acceptable
for supermarkets,it can helps in reducing manpower and creating
better shopping occurence for customers.
Kowshika, Madhumitha S, Madhu Varshini , Megha
Lakshmi (2021); Even through e-commence and other online
applications are growing rapidly the craze for traditional
shopping has never stepped back. One difficulty is to follow up
in a queue for the billing process. There, arises a demand for
easy and quick payment of bills. The proposed Smart Cart in this
paper, is capable of generating bill using IoT along with the
mobile cart application. With the use of this mobile application
and trolley, customer can make bill payment in no time. The
smart cart uses the RFID tag and receiver to scan the product,
load cell to prevent theft, LCD display and the Raspberry p i
Along with this the customer can also log in with the mobile app
which will display the list of all the products mentioned and their
amount. Once done, the customer can pay the bill through the
mobile application.
Tapan Kumar Das, Kathiravan Srinivasan (2020); Shopping
is really fascinating and alluring; at the same time, it involves
getting tired due to standing in a long queue for the bill and
payment process. Hence, it is proposed to design a smart trolley
which can take care of shopping and billing. By this, the customer
can walk straightaway into the shop, purchase products using
the smart trolley and walk out of the shop. He gets the e-bill
through the mail, and he can view his purchase details using the
shop's website. In order to realize this, we need an Arduino
board, Radio-Frequency Identification (RFID) reader, RFID tag,
LCD display, ESP8266 Wi-Fi module, database manager and a
website to maintain product and customer details, which can be
accessed by the admin anywhere in the world. This is an IOT

4
based system where the trolley can interact with the network
spread worldwide.
P. Chandrasekar and T. Sangeetha(2020), Contemporary
embedded systems are habitually based on microcontroller's i.e.
CPUs in the company of integrated memory as well as peripheral
interfaces but ordinary microprocessors by means of external
chips for memory and peripheral interface circuits are also still
common, especially in more complex systems. Radio frequency
identification (RFID) technology may not only be useful for
streamlining inventory and supply chains: it could also make
shoppers swarm. ZigBee is based on an IEEE 802.15 standard.
ZigBee devices often transmit data over longer distances by
passing data through intermediate devices to reach more distant
ones, creating a mesh network; i.e., a network with no
centralized control or high-power transmitter/receiver able to
reach all of the networked devices. This paper provides
centralized and automated billing system using RFID and ZigBee
communication. Each product of shopping mall, super markets
will be provided with a RFID tag, to identify its type. Each
shopping cart is designed or implemented with a Product
Identification Device (PID) that contains microcontroller, LCD, an
RFID reader, EEPROM, and ZigBee module. Purchasing
product information will be read through a RFID reader on
shopping cart, mean while product information will be stored into
EEPROM attached to it and EEPROM data will be send to
Central Billing System through ZigBee module. The central
billing system gets the cart information and EEPROM data, it
access the product database and calculates the total amount of
purchasing for that particular cart. Main aim of this paper was to
provide an automatic billing to avoid queue in malls and super
markets.

5
 Chapter 3

Problem definition:

• Shopping is simple but waiting on a bill counter makes

shopping too boring and a tedious task. Huge amount of
rush plus cashier preparing the bill is too time consuming
and results in long que. In this prevailing pandemic
standing in queues for billing in malls or shopping market
is not advisable as virus may spread.
• The present billing system is time consuming process
which irritates people by disturbing their busy schedules.

6
 Chapter 4

Proposed system & objectives:

Proposed system:
 An automated smart shopping system is formed by
introducing the concept of IoT to connect all items in the
grocery shop. In this system, an inexpensive RF-ID tag is
embedded within each product.
 When the product is placed into a smart cart, the product
detail such as price and weight are automatically read by
the cart equipped with an RF-ID reader.
 And the details are shown on lcd as well as the
webserver.
Hence, billing is made from the shopping cart itself preventing
customers from waiting in a long queue at checkout.

Objectives:
The objectives are detailed as follows,
 To find an efficient way to implement this cart feesable.
 To scan and update the price of item in webserver.
 To have a detailed bill description.

7
 4.1 Block diagram & CIRCUIT
DIAGRAM

Fig 4.1: block diagram of proposed system

Hardware Required:
 Node MCU and Arduino IDE
 Jumper Wires
 RFID reader
 RFID cards
 USB Host
 LED

8
  Push button
Software Required:
 Arduino ide
 Embedded C
 HTML

Fig 4.2 Circuit diagram

9
 4.2 FLOW CHART OF PROPOSED
SYSTEM

Fig 4.3flow chart of proposed system

4.3 Hardware Description

EMBEDDED SYSTEMS

10
4.3.1 Overview of embedded systems

An embedded system is a special-purpose computer

system designed to perform one or a few dedicated functions,
often with real-time computing constraints. It is usually embedded
as part of a complete device including hardware and mechanical
parts. In contrast, a general-purpose computer, such as a
personal computer, can do many different tasks depending on
programming. Embedded systems have become very important
today as they control many of the common devices we use.
Since the embedded system is dedicated to specific tasks,
design engineers can optimize it, reducing the size and cost of the
product, or increasing the reliability and performance. Some
embedded systems are mass-produced, benefiting from
economies of scale.
Physically, embedded systems range from portable
devices such as digital watches and MP3 players, to large
stationary installations like traffic lights, factory controllers, or the
systems controlling nuclear power plants. Complexity varies from
low, with a single microcontroller chip, to very high with multiple
units, peripherals and networks mounted inside a large chassis or
enclosure.
In general, "embedded system" is not an exactly defined term, as
many systems have some element of programmability. For
example, Handheld computers share some elements with
embedded systems — such as the operating systems and
microprocessors which power them — but are not truly embedded
systems, because they allow different applications to be loaded
and peripherals to be connected.
Embedded systems provide several functions

11
• Monitor the environment; embedded systems read data from
input sensors. This data is then processed and the results
displayed in some format to a user or users
• Control the environment; embedded systems generate and
transmit commands for actuators.
• Transform the information; embedded systems transform the
data collected in some meaningful way, such as data
compression/decompression
Although interaction with the external world via sensors and
actuators is an important aspect of embedded systems, these
systems also provide functionality specific to their applications.
Embedded systems typically execute applications such as control
laws, finite state machines, and signal processing algorithms.
These systems must also detect and react to faults in both the
internal computing environment as well as the surrounding
electromechanical systems.
There are many categories of embedded systems, from
communication devices to home appliances to control systems.
Examples include;
• Communication devices
eg.: modems, cellular phones
• Home Appliances
eg.: CD player, VCR, microwave oven
• Control Systems
eg.: Automobile anti-lock braking systems, robotics, satellite
control

4.3.2 Block diagram of an embedded system:

12
 An embedded system usually contains an embedded
processor. Many appliances that have a digital interface --
microwaves, VCRs, cars -- utilize embedded systems. Some
embedded systems include an operating system. Others are very
specialized resulting in the entire logic being implemented as a
single program. These systems are embedded into some device
for some specific purpose other than to provide general purpose
computing . A typical embedded system is shown in Fig

Fig 4.4 block diagram of a typical embedded system

Application Specific Systems:

Embedded systems are not general-purpose computers.
Embedded system designs are optimized for a specific
application. Many of the job characteristics are known before the
hardware is designed. This allows the designer to focus on the
13
specific design constraints of a well-defined application. As such,
there is limited user reprogram ability. Some embedded systems,
however, require the flexibility of reprogram ability. Programmable
DSPs are common for such applications.
Reactive Systems
As mentioned earlier, a typical embedded systems model
responds to the environment via sensors and control the
environment using actuators. This requires embedded systems to
run at the speed of the environment. This characteristic of
embedded system is called “reactive”. Reactive computation
means that the system (primarily the software component)
executes in response to external events. External events can be
either periodic or aperiodic. Periodic events make it easier to
schedule processing to guarantee performance. Aperiodic events
are harder to schedule. The maximum event arrival rate must be
estimated in order to accommodate worst case situations. Most
embedded systems have a significant reactive component. One
of the biggest challenges for embedded system designers is
performing an accurate worst case design analysis on systems
with statistical performance characteristics (e.g., cache memory
on a DSP or other embedded processor). Real time system
operation means that the correctness of a computation depends,
in part, on the time at which it is delivered. Systems with this
requirement must often design to worst case performance. But
accurately predicting the worst case may be difficult on
complicated architectures. This often leads to overly pessimistic
estimates erring on the side of caution. Many embedded systems
have a significant requirement for real time operation in order to
meet external I/O and control stability requirements. Many real-
time systems are also reactive systems.
Distributed Systems
A common characteristic of an embedded system is one that
consists of communicating processes executing on several CPUs
14
or ASICs which are connected by communication links. The
reason for this is economy. Economical 4 8-bit microcontrollers
may be cheaper than a32-bit processors. Even after adding the
cost of the communication links, this approach may be preferable.
In this approach, multiple processors are usually required to
handle multiple time-critical tasks. Devices under control of
embedded systems may also be physically distributed.
Heterogeneous Architectures
Embedded systems often are composed of heterogeneous
architectures. They may contain different processors in the same
system solution. They may also be mixed signal systems. The
combination of I/O interfaces, local and remote memories, and
sensors and actuators makes embedded system design truly
unique. Embedded systems also have tight design constraints,
and heterogeneity provides better design flexibility.

Fig 4.5 Embedded Systems having Heterogeneous Architectures

Harsh environment
Many embedded systems do not operate in a controlled
environment. Excessive heat is often a problem, especially in
applications involving combustion (e.g., many transportation
applications). Additional problems can be caused for embedded
computing by a need for protection from vibration, shock,
lightning, power supply fluctuations, water, corrosion, fire, and
general physical abuse.

15
 4.4 System safety and reliability
As embedded system complexity and computing power
continue to grow, they are starting to control more and more of the
safety aspects of the overall system. These safety measures may
be in the form of software as well as hardware control. Mechanical
safety backups are normally activated when the computer system
loses control in order to safely shut down system operation.
Software safety and reliability is a bigger issue. Software doesn't
normally "break" in the sense of hardware. However software may
be so complex that a set of unexpected circumstances can cause
software failures leading to unsafe situations. Discussion of this
topic is outside the scope of this book, but the challenges for
embedded designers include designing reliable software and
building cheap, available systems using unreliable components.
The main challenge for embedded system designers is to obtain
low-cost reliability with minimal redundancy.
Control of physical systems
One of the main reasons for embedding a computer is to
interact with the environment. This is often done by monitoring
and controlling external machinery. Embedded computers
transform the analog signals from sensors into digital form for
processing. Outputs must be transformed back to analog signal
levels. When controlling physical equipment, large current loads
may need to be switched in order to operate motors and other
actuators. To meet these needs, embedded systems may need
large computer circuit boards with many non-digital components.
Embedded system designers must carefully balance system
tradeoffs among analog components, power, mechanical,
network, and digital hardware with corresponding software.
Small and low weight
Many embedded computers are physically located within
some larger system. The form factor for the embedded system
16
may be dictated by aesthetics. For example, the form factor for a
missile may have to fit inside the nose of the missile. One of the
challenges for embedded systems designers is to develop non-
rectangular geometries for certain solutions. Weight can also be
a critical constraint. Embedded automobile control systems, for
example, must be light weight for fuel economy. Portable CD
players must be light weight for portability purposes.
Cost sensitivity
Cost is an issue in most systems, but the sensitivity to cost
changes can vary dramatically in embedded systems. This is
mainly due to the effect of computer costs have on profitability and
is more a function of the proportion of cost changes compared to
the total system cost.
Power management
Embedded systems have strict constraints on power. Given
the portability requirements of many embedded systems, the need
to conserve power is important to maintain battery life as long as
possible. Minimization of heat production is another obvious
concern for embedded systems.

4.4.1 POWER SUPPLY

All electronic circuits works only in low DC voltage, so we
need a power supply unit to provide the appropriate voltage
supply for their proper functioning. This unit consists of
transformer, rectifier, filter & regulator. AC voltage of typically
230volts rms is connected to a transformer voltage down to the
level to the desired ac voltage. A diode rectifier that provides the
full wave rectified voltage that is initially filtered by a simple
capacitor filter to produce a dc voltage. This resulting dc voltage
usually has some ripple or ac voltage variation . A regulator
circuit can use this dc input to provide dc voltage that not only
has much less ripple voltage but also remains the same dc value

17
even the dc voltage varies some what, or the load connected
to the output dc voltages changes.

Fig 4.6 General Block Of Power Supply Unit

4.4.2 TRANSFORMER:

A transformer is a static piece of which electric power in one

circuit is transformed into electric power of same frequency in
another circuit. It can raise or lower the voltage in the circuit, but
with a corresponding decrease or increase in current. It works with
the principle of mutual induction. In our project we are using a
stepdown transformer to providing a necessary supply for the
electronic circuits. Here we step down a 230volts ac into 12volts
ac.

4.4.3 RECTIFIER:

A dc level obtained from a sinusoidal input can be improved

100% using a process called full wave rectification. Here in our
project for full wave rectification we use bridge rectifier. From the

18
basic bridge configuration we see that two diodes (say D2 & D3)
are conducting while the other two diodes (D1 & D4) are in off
state during the period t = 0 to T/2.Accordingly for the negative
cycle of the input the conducting diodes are D1 & D4. Thus the
polarity across the load is the same.
In the bridge rectifier the diodes may be of variable types
like 1N4001, 1N4003, 1N4004, 1N4005, IN4007 etc.… can be
used. But here we use 1N4007, because it can withstand up to
1000v.

4.4.4 FILTERS:

In order to obtain a dc voltage of 0 Hz, we have to use a low

pass filter. So that a capacitive filter circuit is used where a
capacitor is connected at the rectifier output& a dc is obtained
across it. The filtered waveform is essentially a dc voltage with
negligible ripples & it is ultimately fed to the load.

4.4.5 REGISTERS:
The controller IC has two 8 bit registers, an instruction
register (IR) and a data register (DR). The IR stores the instruction
codes and address information for display data RAM (DD RAM)
and character generator RAM (CG RAM). The IR can be written,
but not read by the MPU. The DR temporally stores data to be
written to /read from the DD RAM or CG RAM. The data written to
DR by the MPU, is automatically written to the DD RAM or CG
RAM as an internal operation.

When an address code is written to IR, the data is

automatically transferred from the DD RAM or CG RAM to the DR.
data transfer between the MPU is then completed when the MPU
reads the DR. likewise, for the next MPU read of the DR, data in
DD RAM or CG RAM at the address is sent to the DR

19
automatically. Similarly, for the MPU write of the DR, the next DD
RAM or CG RAM address is selected for the write operation.

The dot-matrix liquid crystal display controller and driver LSI

displays alphanumeric, Japanese kana characters, and symbols.
It can be configured to drive a dot-matrix liquid crystal display
under the control of a 4- or 8-bit microprocessor. Since all the
functions such as display RAM, character generator, and liquid
crystal driver, required for driving a dot-matrix liquid crystal display
are internally provided on one chip, a minimal system can be
interfaced with this controller/driver

4.4.6 REGULATORS:
The output voltage from the capacitor is more filtered & finally
regulated. The voltage regulator is a device, which maintains the
output voltage constant irrespective of the change in supply
variations, load variations & temperature changes. Here we use
fixed voltage regulator namely LM7805.The IC LM7805 is a +5v
regulator which is used for microcontroller.

4.5 IOT

Let's us look closely at our mobile device which contains

GPS Tracking, Mobile Gyroscope, Adaptive brightness, Voice
detection, Face detection etc. These components have their own
individual features, but what about if these all communicate with
each other to provide a better environment? For example, the
phone brightness is adjusted based on my GPS location or my
direction.
Connecting everyday things embedded with electronics, software,
and sensors to internet enabling to collect and exchange data
without human interaction called as the Internet of Things (IoT).

20
The term "Things" in the Internet of Things refers to anything and
everything in day today life which is accessed or connected
through the internet.

Fig 4.7 Diagram of IOT applications

IoT is an advanced automation and analytics system which

deals with artificial intelligence, sensor, networking, electronic,
cloud messaging etc. to deliver complete systems for the product
or services. The system created by IoT has greater
transparency, control, and performance.

As we have a platform such as a cloud that contains all the

data through which we connect all the things around us. For
example, a house, where we can connect our home appliances
such as air conditioner, light, etc. through each other and all
these things are managed at the same platform. Since we have
a platform, we can connect our car, track its fuel meter, speed
level, and also track the location of the car. If there is a common
platform where all these things can connect to each other would
be great because based on my preference, I can set the room
temperature. For example, if I love the room temperature to to
be set at 25 or 26-degree Celsius when I reach back home from
my office, then according to my car location, my AC would start

21
before 10 minutes I arrive at home. This can be done through the
Internet of Things (IoT).

4.6Embedded Devices
(System) in (IoT)
It is essential to know about the embedded devices while
learning the IoT or building the projects on IoT. The embedded
devices are the objects that build the unique computing system.
These systems may or may not connect to the Internet.

An embedded device system generally runs as a single

application. However, these devices can connect through the
internet connection, and able communicate through other
network devices.

Fig 4.8 Embedded systems with IOT diagram

Embedded System Hardware

22
 The embedded system can be of type microcontroller or
type microprocessor. Both of these types contain an integrated
circuit (IC).The essential component of the embedded system is
a RISC family microcontroller like Motorola 68HC11, PIC 16F84,
Atmel 8051 and many more. The most important factor that
differentiates these microcontrollers with the microprocessor like
8085 is their internal read and writable memory. The essential
embedded device components and system architecture are
specified below.

4.7 Embedded System Software

The embedded system that uses the devices for the
operating system is based on the language platform, mainly
where the real-time operation would be performed.
Manufacturers build embedded software in electronics, e.g.,
cars, telephones, modems, appliances, etc. The embedded
system software can be as simple as lighting controls running
using an 8-bit microcontroller. It can also be complicated
software for missiles, process control systems, airplanes etc.

4.8 Nodemcu

NodeMCU is an open source IoT platform. It

includes firmware which runs on the ESP8266 Wi-
Fi SoC from Espressif Systems, and hardware which is based
on the ESP-12 module. The term "NodeMCU" by default refers
to the firmware rather than the development kits. The firmware
uses the Lua scripting language. It is based on the eLua project,
and built on the Espressif Non-OS SDK for ESP8266. It uses
many open source projects, such as lua-cjson and SPIFFS

23
 NodeMCU was created shortly after the ESP8266 came
out. On December 30, 2013, Espressif Systems began
production of the ESP8266. The ESP8266 is a Wi-Fi SoC
integrated with a Tensilica Xtensa LX106 core, widely used in
IoT applications (see related projects). NodeMCU started on 13
Oct 2014, when Hong committed the first file of nodemcu-
firmware to GitHub. Two months later, the project expanded to
include an open-hardware platform when developer Huang R
committed the gerber file of an ESP8266 board, named devkit
v0.9.Later that month, Tuan PM ported MQTT client library
from Contiki to the ESP8266 SoC platform, and committed to
NodeMCU project, then NodeMCU was able to support the
MQTT IoT protocol, using Lua to access the MQTT broker.
Another important update was made on 30 Jan 2015, when
Devsaurus ported the u8glib to NodeMCU project, enabling
NodeMCU to easily drive LCD, Screen, OLED, even VGA
displays.
In summer 2015 the creators abandoned the firmware project
and a group of independent contributors took over. By summer
2016 the NodeMCU included more than 40 different modules.
Due to resource constraints users need to select the modules
relevant for their project and build a firmware tailored to their
needs.

ESP8266 Arduino Core

As Arduino.cc began developing new MCU boards based
on non-AVR processors like the ARM/SAM MCU and used in the
Arduino Due, they needed to modify the Arduino IDE so that it
would be relatively easy to change the IDE to support alternate
toolchains to allow Arduino C/C++ to be compiled for these new
processors. They did this with the introduction of the Board
Manager and the SAM Core. A "core" is the collection of software

24
components required by the Board Manager and the Arduino
IDE to compile an Arduino C/C++ source file for the target MCU's
machine language. Some ESP8266 enthusiasts developed an
Arduino core for the ESP8266 WiFi SoC, popularly called the
"ESP8266 Core for the Arduino IDE".[16] This has become a
leading software development platform for the various ESP8266-
based modules and development boards, including NodeMCUs.

4.9 RFID technology

RFID or Radio Frequency Identification system consists of two

main components, a transponder/tag attached to an object to be
identified, and a Transceiver also known as interrogator/Reader .

Fig 4.9 diagram of rfid technology

A Reader consists of a Radio Frequency module and an

antenna which generates high frequency
electromagnetic field. On the other hand, the tag is
usually a passive device, meaning it doesn’t contain a
battery. Instead it contains a microchip that stores and

25
processes information, and an antenna to receive and
transmit a signal.
To read the information encoded on a tag, it is placed in
close proximity to the Reader (does not need to be
within direct line-of-sight of the reader). A Reader
generates an electromagnetic field which causes
electrons to move through the tag’s antenna and
subsequently power the chip.
The powered chip inside the tag then responds by sending its
stored information back to the reader in the form of another
radio signal. This is called backscatter. The backscatter, or
change in the electromagnetic/RF wave, is detected and
interpreted by the reader which then sends the data out to a
computer or microcontroller.

Hardware Overview – RC522 RFID

Reader/Writer Module
The RC522 RFID Reader module is designed to create a
13.56MHz electromagnetic field that it uses to communicate
with the RFID tags (ISO 14443A standard tags). The reader
can communicate with a microcontroller over a 4-pin Serial
Peripheral Interface (SPI) with a maximum data rate
of 10Mbps. It also supports communication over I2C and UART
protocols.
The module comes with an interrupt pin. It is handy because
instead of constantly asking the RFID module “is there a card in
view yet? “, the module will alert us when a tag comes into its
vicinity.
The operating voltage of the module is from 2.5 to 3.3V, but the
good news is that the logic pins are 5-volt tolerant, so we can

26
easily connect it to an Arduino or any 5V logic microcontroller
without using any logic level converter.

Here are complete specifications:

Frequency Range 13.56 MHz ISM Band

Host Interface SPI / I2C / UART
Operating Supply Voltage 2.5 V to 3.3 V
Max. Operating Current 13-26mA
Min. Current (Power down) 10µA
Logic Inputs 5V Tolerant

Range
5cm

Fig 4.10 RC522 RFID PIN CONFIGURATION

VCC: supplies power for the module. This can be anywhere from
2.5 to 3.3 volts. You can connect it to 3.3V output from your
Arduino. Remember connecting it to 5V pin will likely destroy
your module!

27
RST: is an input for Reset and power-down. When this pin goes
low, hard power-down is enabled. This turns off all internal
current sinks including the oscillator and the input pins are
disconnected from the outside world. On the rising edge, the
module is reset.

GND: is the Ground Pin and needs to be connected to GND pin

on the Arduino.
IRQ: is an interrupt pin that can alert the microcontroller when
RFID tag comes into its vicinity.

MISO / SCL / Tx pin: acts as Master-In-Slave-Out when SPI

interface is enabled, acts as serial clock when I2C interface is
enabled and acts as serial data output when UART interface is
enabled.

MOSI (Master Out Slave In): is SPI input to the RC522 module.
SCK (Serial Clock) : accepts clock pulses provided by the SPI
bus Master i.e. Arduino.

SS / SDA / Rx pin : acts as Signal input when SPI interface is

enabled, acts as serial data when I2C interface is enabled and
acts as serial data input when UART interface is enabled. This
pin is usually marked by encasing the pin in a square so it can
be used as a reference for identifying the other pins.

28
 Chapter 5

Result and discussion

Whenever the customer using this cart is adding a product

into the shopping cart the product that is attached with RFID tag
is scanned and the details required are fetched. These details
are then fed into the microcontroller and based on the code the
microcontroller then produces a bill with required fields in it. This
bill gets updated within no time the product gets added to it. The
bill is then displayed on lcd screen and also on the webserver
which makes customer more comfortable in viewing the detailed
bill of products added and then cross check for the products to
be added. The products can also be removed from cart, when
the customer wants to remove a product he can use the push
button and scan it so the product is removed from the bill.

29
Fig5.2 bill outcome on webserver

30
 Chapter 6

CONCLUSION
The basic idea is to make shopping more easy and
comfortable in the overpopulated cities. This shopping cart is
built with a system that enables customer to bill their products at
cart itself without standing in long ques for billing.
Finally, a system named smart shopping cart is designed in
which the microcontroller(node mcu) and rfid technology plays a
vital role in scanning the products,preparing bill and displaying it
on lcd and also uploading the same into the webserver .This
helps the user to view the bill on his/her device.

31
REFERENCES:

1. B. Kumar Yadav, A. Burman, A. Mahato, M. Choudhary and

A. Kundu, "Smart Cart: A Distributed Framework," 2020
IEEE 1st International Conference for Convergence in
Engineering (ICCE), 2020.
2. S. Kowshika, S. S. Madhu mitha, G. Madhu Varshini, V.
Megha and K. Lakshmi, "IoT based Smart Shopping Trolley
with Mobile Cart Application," 2021 7th International
Conference on Advanced Computing and Communication
Systems (ICACCS), 2021.
3. T. K. Das, A. K. Tripathy and K. Srinivasan, "A Smart Trolley
for Smart Shopping," 2020 International Conference on
System, Computation, Automation and Networking
(ICSCAN), 2020.
4. Sakorn Mekruksavanich, “The Smart Shopping Basket
Based on IoT Applications”, Software Engineering and
Service Science (ICSESS) 2019 10th International
Conference, 2019.
5. A. D, S. S. Guddad, A. S, K. Yanamala and S. S, "Smart
Shopping Cart using IOT and robotic arm," 2021
International Conference on Design Innovations for 3Cs
Compute Communicate Control (ICDI3C), 2021.
6. Vishwanadha V, Pavan Kumar P and Chiranjeevi Reddy S,
“Smart Shopping Cart”, International Conference on

32