VPM’s B.N.Bandodkar College of Science ( Autonomous ),Thane.

Department of Information Technology.

Subject :- Internet of Things
Practical Code :- BNBUSIT5P2

Signature of
Sr.No Index Date
Teacher
Study of
1. Raspberry Pi
1.
2.Arduino
3.Node MCU

2. Study of IoT Sensors.

Study of RFID, Buzzer, Bread board, Relay, 7

3.
Segment Display
Study of Display, LED, LED Grid Module,
4.
USB, GPS

5. Study of Jumper Wires used in IoT

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Practical No. 01

AIM : Study of 1. Raspberry Pi 2.Arduino 3.Node MCU

Raspberry Pi

Raspberry Pi is the name of a series of single-board computers made by the Raspberry Pi

Foundation, a UK charity that aims to educate people in computing and create easier access to
computing education.

The Raspberry Pi launched in 2012, and there have been several iterations and variations
released since then. The original Pi had a single-core 700MHz CPU and just 256MB RAM, and
the latest model has a quad-core CPU clocking in at over 1.5GHz, and 4GB RAM. The price
point for Raspberry Pi has always been under $100 (usually around $35 USD), most notably the
Pi Zero, which costs just $5.

All over the world, people use the Raspberry Pi to learn programming skills, build hardware
projects, do home automation, implement Kubernetes clusters and Edge computing, and even use
them in industrial applications.

The Raspberry Pi is a very cheap computer that runs Linux, but it also provides a set of GPIO
(general purpose input/output) pins, allowing you to control electronic components for physical
computing and explore the Internet of Things (IoT).

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Arduino UNO

The Arduino UNO is a standard board of Arduino. Here UNO means 'one' in Italian. It was
named as UNO to label the first release of Arduino Software. It was also the first USB board
released by Arduino. It is considered as the powerful board used in various projects. Arduino.cc
developed the Arduino UNO board.

Arduino UNO is based on an ATmega328P microcontroller. It is easy to use compared to other

boards, such as the Arduino Mega board, etc. The board consists of digital and analog
Input/Output pins (I/O), shields, and other circuits.

The Arduino UNO includes 6 analog pin inputs, 14 digital pins, a USB connector, a power jack,
and an ICSP (In-Circuit Serial Programming) header. It is programmed based on IDE, which
stands for Integrated Development Environment. It can run on both online and offline platforms.

The IDE is common to all available boards of Arduino.

The Arduino board is shown below:

The components of Arduino UNO board are shown below:

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Let's discuss each component in detail.

o ATmega328 Microcontroller- It is a single chip Microcontroller of the ATmel family.

The processor code inside it is of 8-bit. It combines Memory (SRAM, EEPROM, and
Flash), Analog to Digital Converter, SPI serial ports, I/O lines, registers, timer,
external and internal interrupts, and oscillator.
o ICSP pin - The In-Circuit Serial Programming pin allows the user to program using the
firmware of the Arduino board.
o Power LED Indicator- The ON status of LED shows the power is activated. When the
power is OFF, the LED will not light up.
o Digital I/O pins- The digital pins have the value HIGH or LOW. The pins numbered
from D0 to D13 are digital pins.
o TX and RX LED's- The successful flow of data is represented by the lighting of these
LED's.
o AREF- The Analog Reference (AREF) pin is used to feed a reference voltage to the
Arduino UNO board from the external power supply.
o Reset button- It is used to add a Reset button to the connection.
o USB- It allows the board to connect to the computer. It is essential for the programming
of the Arduino UNO board.
o Crystal Oscillator- The Crystal oscillator has a frequency of 16MHz, which makes the
Arduino UNO a powerful board.
o Voltage Regulator- The voltage regulator converts the input voltage to 5V.
o GND- Ground pins. The ground pin acts as a pin with zero voltage.
o Vin- It is the input voltage.
o Analog Pins- The pins numbered from A0 to A5 are analog pins. The function of Analog
pins is to read the analog sensor used in the connection. It can also act as GPIO (General
Purpose Input Output) pins.

NodeMCU
NodeMCU is an open-source LUA based firmware developed for the ESP8266 wifi chip. By exploring functionality with
the ESP8266 chip, NodeMCU firmware comes with the ESP8266 Development board/kit i.e. NodeMCU Development
board.

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Since NodeMCU is an open-source platform, its hardware design is open for edit/modify/build.
NodeMCU Dev Kit/board consist of ESP8266 wifi enabled chip. The ESP8266 is a low-cost Wi-
Fi chip developed by Espressif Systems with TCP/IP protocol. For more information about
ESP8266, you can refer to the ESP8266 WiFi Module.
There is Version2 (V2) available for NodeMCU Dev Kit i.e. NodeMCU Development Board
v1.0 (Version2), which usually comes in black colored PCB.

For more information about NodeMCU Boards available in the market refer to NodeMCU
Development Boards
NodeMCU Dev Kit has Arduino like Analog (i.e. A0) and Digital (D0-D8) pins on its board.
It supports serial communication protocols i.e. UART, SPI, I2C, etc.
Using such serial protocols we can connect it with serial devices like I2C enabled LCD display,
Magnetometer HMC5883, MPU-6050 Gyro meter + Accelerometer, RTC chips, GPS modules,
touch screen displays, SD cards, etc.

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Practical No. 02

AIM : Study of IoT Sensors.

What are IoT Sensors?

IoT sensors are pieces of hardware that detect changes in an environment and collect data. They‟re the
pieces of an IoT ecosystem that bridge the digital world to the physical world. IoT sensors may detect
things like temperature, pressure, and motion, and if they are connected to a network, they share data with
the network.

14 Types of IoT Sensors

There are many different types of sensors, and they come in different shapes and sizes. Here are 14 of the
most common types and uses of sensors.

1. Temperature Sensors
Temperature sensors measure the amount of heat generated from an area or an object. They detect a
temperature change and convert the findings to data. Temperature sensors are used in various industries,
including manufacturing, healthcare, and agriculture. Some examples are thermistors, thermocouples, and
resistor temperature detectors (RTD).

2. Proximity Sensors
Proximity sensors detect the presence or absence of objects near the sensor without physical contact. They
often emit a beam of radiation like infrared or an electromagnetic field. They can be used for process

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monitoring and control, object counting, assembly lines, and determining available space. Proximity
sensors are common in retail settings, industrial complexes, and parking lots. Some examples are
photoelectric, magnetic, capacitive, inductive, and ultrasonic.

3. Pressure Sensors
These sensors detect changes in a gas or liquid. When the pressure range is beyond a set threshold,
pressure sensors alert to the problem. They are used for leak testing, water systems, vehicles, and aircraft.
For example, the BMP180 is a digital pressure sensor found in cell phones and GPS navigation devices.
And some vehicles use a tire pressure monitoring system (TPMS) to alert when tire pressure is low and
potentially unsafe.

4. Water Quality Sensors

As you‟d expect, water quality sensors monitor the quality of water. They are often used in water
distribution systems, but they function in a variety of industries. There are different kinds of water
sensors, including residual chlorine sensors, turbidity sensors, pH sensors, and total organic carbon
sensors.

5. Chemical and Gas Sensors

These sensors monitor air quality for the presence of toxic or hazardous gas. They often use
semiconductor, electrochemical, or photo-ionization technologies for detection. They are typically used in
industrial and manufacturing settings, though they are also found in carbon dioxide detectors.

6. Infrared Sensors
Some sensors either detect or emit infrared radiation to sense characteristics and changes in the
surrounding area. They‟re useful for measuring heat emissions from an object. Infrared sensors are used
in remote controls, healthcare settings, and even by art historians authenticating artwork.

7. Smoke Sensors
Most people are familiar with smoke detectors, as they have protected our homes and businesses for a
long time. However, with improvements based on IoT, smoke detectors are now more user-friendly,
convenient, and wire-free.

8. Motion Sensors
Motion sensors detect physical movement in an area. Of course, these sensors play a significant role in
the security industry, but they are used in nearly every industry. Applications include automated sinks and
toilet flushers, automatic door controls, energy management systems, and automated parking systems.
Standard motion sensors include ultrasonic, microwave, and passive infrared (PIR).

9. Level Sensors
Level sensors detect the level of various substances, including powder, granular material, and liquids.
Industries that use them include water treatment, food and beverage manufacturing, oil manufacturing,

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and waste management. They can detect the level of liquid in a container and can even determine the
amount of waste in a dumpster.

10. Image Sensors

These sensors convert optical images into signals and are generally used to display or store files
electronically. They are found in radar and sonar, biometric devices, night vision equipment, medical
imaging, digital cameras, and even some cars. Charge-coupled devices (CCD) and complementary metal-
oxide semiconductors (CMOS) are most commonly used.

11. Humidity Sensors

These sensors measure the amount of water vapor in the air. Typical uses include heating and air
conditioning systems (HVAC) and weather monitoring and prediction. When humidity must be tightly
controlled, such as in museums, hospitals, and greenhouses, humidity sensors assist the process.

12. Accelerometer Sensors

Accelerometer sensors detect the orientation of an object and the rate of change, including tap, shake, tilt,
and positioning. They are used in many industries for smart pedometers, anti-theft protection, and
monitoring auto fleets. Some types are capacitive accelerometers and hall-effect accelerometers.

13. Gyroscope Sensors

A gyroscope sensor measures the angular rate or velocity, or the speed of rotation around an axis. They
are generally used for navigation in the auto industry for navigation and anti-skid systems as well as in
video games and drones. Some examples include optical gyroscopes, rotary gyroscopes, and vibrating
structure gyroscopes.

14. Optical Sensors

Optical sensors measure light and convert it into electrical signals. Many industries make use of optical
sensors, including auto, energy, healthcare, and aerospace. Sensors include fiber optics, photodetector,
and pyrometer.

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Practical No. 03

AIM : Study of RFID, Buzzer, Bread board, Relay, 7 Segment Display

Radio Frequency Identification (RFID)

Radio Frequency Identification (RFID) is a form of wireless communication that

incorporates the use of electromagnetic or electrostatic coupling in the radio frequency portion
of the electromagnetic spectrum to uniquely identify an object or person. It uses radio
frequency to search, identify, track, and communicate with items and people.
RFID (Radio Frequency Identification) is a technology that uses electromagnetic fields to
automatically identify and track tags attached to objects. These tags contain electronically
stored information that can be read from several meters away, without requiring direct line-of-
sight. RFID is commonly used in inventory management, asset tracking, access control, and
supply chain logistics due to its efficiency and accuracy in tracking and managing items.
It is a method that is used to track or identify an object by radio transmission over the web.
Data is digitally encoded in an RFID tag which might be read by the reader. This device works
as a tag or label during which data is read from tags that are stored in the database through the
reader as compared to traditional barcodes and QR codes. It is often read outside the road of
sight either passive or active RFID.

Buzzer
Buzzer is a kind of voice device that converts audio model into sound signal. It is
mainly used to prompt or alarm. According to different design and application, it
can produce music sound, flute sound, buzzer, alarm sound, electric bell and other
different sounds.
Typical applications include siren, alarm device, fire alarm, air defense alarm,
burglar alarm, timer, etc. It is widely used in household appliances, alarm system,
automatic production line, low-voltage electrical equipment, electronic toys, game
machines and other products and industries.

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Breadboard

The breadboard is a white rectangular board with small embedded holes to insert electronic
components. It is commonly used in electronics projects. We can also say that breadboard is a
prototype that acts as a construction base of electronics.

The breadboard is shown in the below image:

A breadboard is derived from two words bread and board. The word breadboard was initially
used to slice the bread pieces. But, it was further named as a breadboard for its use in electronics
around the 1970s. Hence, the term breadboard refers to these boards only and provides a quick
electrical connection.

A breadboard is also categorized as a Solderless board. It means that the component does not
require any soldering to fit into the board. Thus, we can say that breadboard can be reused. We
can easily fit the components by plugging their end terminal into the board. Hence, a breadboard
is often called a plugboard.

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Relay

A relay is an electrically operated electronic switch that is commonly used in circuits and
systems to control higher power signals with lower power inputs. The term "relay" comes from
the French word "relais" which means to pass on. In simple terms, a relay allows a small
electrical circuit to switch a separate high-powered circuit. The relay is a type of an electronic
switch that opens or close the circuit contacts by using electronic component without any
mechanical operation. In this relay, the current carrier pilot relaying scheme is used for the
protection of the transmission line.

This article focuses on what is relay, its working, types, applications and testing in detail through
different sections.The information in this article helps you extensively in your SSC JE
Electrical and GATE Electrical preparation journey.

Construction of Relay

A basic electromechanical relay consists of an electromagnet, armature, and set of contacts. The
electromagnet is made up of a coil that receives input signals and a soft iron core. When voltage
is applied to the coil, it gets magnetized due to electric current flowing through the coil windings.
The armature is a movable piece of soft iron attracted by the magnetic field created by the
electromagnet. A set of normally open (NO) and normally closed (NC) contacts are attached to
the armature which opens or closes depending on the armature's position.

Basic components of relay is given in below table:

Component Description
Electromagnet Generates magnetic field upon energization
Armature Movable piece that responds to the magnetic field
Contacts Conductors that open/close the electrical circuit
Spring Returns the armature to its original position

Seven Segment Displays

Light Emitting Diode (LED) is the most widely used semiconductor which emits either visible
light or invisible infrared light when forward biased. Remote controls generate invisible light. A
Light-emitting diode (LED) is optical-electrical energy into light energy when voltage is applied.

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Seven Segment Displays
Seven segment displays are the output display device that provides a way to display information
in the form of images or text or decimal numbers which is an alternative to the more complex dot
matrix displays. It is widely used in digital clocks, basic calculators, electronic meters, and other
electronic devices that display numerical information. It consists of seven segments of light-
emitting diodes (LEDs) which are assembled like numerical 8.

Working of Seven Segment Displays

The number 8 is displayed when the power is given to all the segments and if you disconnect the
power for „g‟, then it displays the number 0. In a seven-segment display, power (or voltage) at
different pins can be applied at the same time, so we can form combinations of display numerical
from 0 to 9. Since seven-segment displays can not form alphabets like X and Z, so it can not be
used for the alphabet and they can be used only for displaying decimal numerical magnitudes.
However, seven-segment displays can form alphabets A, B, C, D, E, and F, so they can also be
used for representing each display unit is usually has a dot point (DP). The display point could
be located either towards the left or towards the right of the display pattern. This type of pattern
can be used to display numerals from 0 to 9 and letters from to F hexadecimal digits.

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Practical No. 04

AIM : Study of Display, LED, LED Grid Module, USB, GPS

What is a Display?
A display is a screen that shows pictures and words from a computer or other device. It has
many tiny bright dots called pixels that light up to create the images we see. The display has
multiple layers that allow it to show these images. Different displays may have slightly
different layers, based on how they work. Displays let us interact with computers, phones,
TVs, etc. by showing us information like text and graphics. We use keyboards, touchscreens,
or other inputs along with the display.
In laptops and tablets, the display is already built into the device itself. But for desktops and
computers, the display is usually a separate screen called a monitor that connects to the
computer. The words “display” and “monitor” mean similar things and are often used in place
of each other. But not all displays are monitors some are just screens without being a separate
monitor device.

Types of Computer Displays

1. Cathode Ray Tube (CRT)
Initially, these were mainly used as displays but they were large and very heavy with high
power consumption rates. Cathode Ray Tubes works by directing electron beams onto the back
surface of a screen causing it to emit light.
2. Liquid Crystal Display (LCD)
This type of display is flat and thin. It functions through the blocking of light rather than
creating it like other types do. There are two glass layers with liquid crystal material between
them in an Liquid Crystal Display. The crystals rotate to either allow or block light that creates
images on screens. They are popular because they are slim and consume less power compared
to CRTs.
3. Light Emitting Diode (LED)
In LED displays, small lights referred to as LEDs are used as their lighting source instead of
other backlights like those found in LCDs . This makes them thinner and lighter than any other
kind of display device panel can be made thinner using this technology too which contributes
towards improved color and brightness features OLED uses organic materials while QLED
utilizes nanoparticles for producing different kinds of LED displays

LED

A light-emitting diode (LED) is a semiconductor device that emits light when an electric current
flows through it. When current passes through an LED, the electrons recombine with holes

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emitting light in the process. LEDs allow the current to flow in the forward direction and blocks
the current in the reverse direction.
Light-emitting diodes are heavily doped p-n junctions. Based on the semiconductor material used
and the amount of doping, an LED will emit coloured light at a particular spectral wavelength
when forward biased. As shown in the figure, an LED is encapsulated with a transparent cover so
that emitted light can come out.
Read More: Diodes

LED Symbol
The LED symbol is the standard symbol for a diode, with the addition of two small arrows
denoting the emission of light.

Uses of LED
LEDs find applications in various fields, including optical communication, alarm and security
systems, remote-controlled operations, robotics, etc. It finds usage in many areas because of its
long-lasting capability, low power requirements, swift response time, and fast switching
capabilities. Below are a few standards LED uses:

 Used for TV back-lighting

 Used in displays
 Used in Automotives
 LEDs used in the dimming of lights

Types of LED
Below is the list of different types of LED that are designed using semiconductors:

 Miniature LEDs
 High-Power LEDs
 Flash LED
 Bi and Tri-Colour
 Red Green Blue LEDs
 Alphanumeric LED
 Lighting LED

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LED Matrix Module

This is a common cathode 8x8 dot matrix module driven by MAX7219, the module operating
voltage is 5V, the size is 50mmx32mmx15mm, the left side is input port, the right side is output
port, support multiple modules cascade.

 VCC: Positive Supply Voltage. Connect to +5V.

 GND: Ground (both GND pins must be connected)
 DIN: Serial-Data Input. Data is loaded into the internal 16-bit shift register on CLK‟s rising
edge.
 CS: Chip-Select Input. Serial data is loaded into the shift register while CS is low. The last 16
bits of serial data are latched on CS‟s rising edge.
 CLK: Serial-Clock Input. 10MHz maximum rate. On CLK‟s rising edge, data is shifted into
the internal shift register. On CLK‟s falling edge, data is clocked out of DOUT. On the
MAX7221, the CLK input is active only while CS is low.
MAX7219

The MAX7219 is a compact, serial input/output common-cathode display drivers that interface
microprocessors (µPs) to 7-segment numeric LED displays of up to 8 digits, bar-graph displays,
or 64 individual LEDs. Included on-chip are a BCD code-B decoder, multiplex scan circuitry,
segment and digit drivers, and an 8x8 static RAM that stores each digit.

Only one external resistor is required to set the segment current for all LEDs. The MAX7221 is
compatible with SPI™, QSPI™, and MICROWIRE™, and has slewrate-limited segment drivers
to reduce EMI.

A convenient 4-wire serial interface connects to all common µPs. Individual digits may be
addressed and updated without rewriting the entire display. The MAX7219/MAX7221 also allow
the user to select codeB decoding or no-decode for each digit.

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Universal Serial Bus (USB)
USB was designed to standardize the connection of peripherals like pointing devices, keyboards,
digital images and video cameras. But some devices such as printers, portable media players,
disk drives, and network adaptors to personal computers used USB to communicate and to
supply electric power. It is commonplace to many devices and has largely replaced interfaces
such as serial ports and parallel ports. USB connectors have replaced other types of battery
chargers for portable devices with themselves.

What is a Universal Serial Bus(USB)?

Universal Serial Bus (USB) is an industry standard that establishes specifications for
connectors, cables, and protocols for communication, connection, and power supply between
personal computers and their peripheral devices. There have been 3 generations of USB
specifications:
 USB 1.x
 USB 2.0
 USB 3.x
The first USB was formulated in the mid-1990s. USB 1.1 was announced in 1995 and released in
1996. It was too popular and grab the market till about the year 2000. In the duration of USB 1.1
Intel announced a USB host controller and Philips announced USB audio for isochronous
communication with consumer electronics devices.
In April of 2000, USB 2.0 was announced. USB 2.0 has multiple updates and additions. The
USB Implementer Forum (USB IF) currently maintains the USB standard and it was released in
1996.

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USB Connector Types
USB connectors have different shapes and sizes. Most of the USB connectors are the standard
USB, Mini-USB, and Micro-USB, which have two or more variations of connectors. Information
on each type are shown below.

Mini USB
Mini USB is available in three different types A type, B type, and AB type. It is used with
computer peripherals and digital cameras. The most common kind of interface is this one, that is
referred to as mini B. Micro USB and USB-C cables basically take the place of mini USB on the
latest devices. It uses coaxial cable to transmit data and power between two devices. it applies to
mobile hard drives, digital cameras, and MP3 players. One end of a micro USB cable has a much
smaller quadrilateral hub, and the other end has a regular USB hub with a flat head. It can be
easily plugged into mobile devices. Although the tiny USB is mainly designed for, it can also be
used to transfer data between computers having at least one USB port for charging device.
Micro USB
A reduced version of the USB (Universal Serial Bus), the micro-USB. It was created for
connecting small and mobile devices including digital cameras, smartphones, GPS components,
MP3 players, and photo printers and was first announced in 2007 as a replacement for mini USB.
The three different types of Micro-USB are Micro A, Micro B, and Micro USB 3. The connector
size for the type Micro-A and Micro-B is 6.85 x 1.8 mm, while the Micro-A connector has a
larger maximum overmild size. Because it has more pins on the side for twice as many wires
than micro B, USB 3 micro is more comparable to micro B yet has faster speed. Micro USB and
normal USB versions are both plug-and-play and hot-swappable is still widely used with
electronic devices.
USB Type-C
A USB Type-C port is a relatively new type of connector that may be found on the majority of
contemporary newer Android smartphones and other USB-connected devices. Data and power
are delivered to computing machines using it. In contrast to traditional USB connections, USB-C
cables can be connected into devices in either direction, including upside down.

GPS
GPS module receivers are generally used in smartphones, fleet management systems, military,
etc. for tracking or finding a location.

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 Global Positioning System (GPS) is a satellite-based system that uses satellites and ground
stations to measure and compute its position on Earth.

GPS is also call as Navigation System with Time and Ranging (NAVSTAR) GPS.

GPS receiver gives output in standard (National Marine Electronics Association) NMEA string
format. It provides output serially on the TX pin with default 9600 Baud rate.

This NMEA string output from the GPS receiver contains different parameters like longitude,
latitude, altitude, time, etc. which are separates by commas. Each string starts with „$‟ and ends
with a carriage return/line feed sequence. For e.g

$GPGGA, 184241.000, 1829.9639,N, 07347.6174, E, 1, 05, 2.1, 607.1, M,-64.7, M, ,0000*7C

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Practical No. 05

AIM : Study of Jumper Wires used in IoT

Jumper Wires

Wires that connect two terminals are called jumper wires. There are various kinds of jumper
wires. Here we focus on those used in breadboard. Among others, they are used to transfer
electrical signals from anywhere on the breadboard to the input/output pins of a microcontroller.

Jump wires are fitted by inserting their “end connectors” into the slots provided in the
breadboard, beneath whose surface there are a few sets of parallel plates that connect the slots in
groups of rows or columns depending on the area. The “end connectors” are inserted into the
breadboard, without soldering, in the particular slots that need to be connected in the specific
prototype.

There are three types of jumper wire: Female-to-Female, Male-to-Male, and Male-to-Female.
The reason we call it Male-to-Female is because it has the outstanding tip in one end as well as a
sunk female end. Male-to-Male means both side are male and Female-to-Female means both
ends are female.

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More than one type of them may be used in a project. The color of the jump wires is different but
it doesn‟t mean their function is different accordingly; it‟s just designed so to better identify the
connection between each circuit.

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