IOT lab ManualArduino_IOTArduino_IOTArdu

ES & IOT Lab Manual Page 1
EMBEDDED SYSTEMS & INTERNET OF THINGS
LAB
(IT605PC)
Class: B.Tech III-II Semester
Prepared
by
Mr. Prasad B (Assoc .Prof)
Department
of
INFORMATION TECHNOLOGY

CERTIFICATE
This is to certify that this manual is a bonafide record of practical work in the ES &IOT of
III year B.Tech (IT) programme during the academic year 2020-21. This manual is
prepared by Mr. Prasad Banoth (Assoc. Professor) Department of Computer Science and
Engineering, Mrs. N Pallavi (Asst. Professor) Department of Electronics and
Communication.
Content IC Academic IC HOD
Director Principal

INDEX
S. No Content Page No
1 Preface
2 Acknowledgement
3 General Instructions
4 Institute Vision and Mission
5 Department Vision and Mission
6 Programme Outcomes
7 Programme Educational Objectives
8 Programme Specific Outcomes
9 Course Objectives and Outcomes
10 Course Syllabus
11 Course Experiments

PREFACE
This “ES & IOT” lab manual is intended to teach the design and analysis of IOT systems. To
introduce the terminology, technology and its applications of IOT. To introduce the concept
of M2M (machine to machine) with necessary protocols. To introduce the Python Scripting
Language which is used in many IoT devices. To introduce the Raspberry PI platform, that is
widely used in IoT applications. To introduce the implementation of web-based services on
IoT devices. The manual contains the exercise programs and their solution for easy & quick
understanding of the students. We hope that this practical manual will be helpful for students
of IT for understanding the subject from the point of view of applied aspects. There is always
scope for improvement in the manual. We would appreciate to receive valuable suggestions
from readers and users for future use.

ACKNOWLEDGEMENT
It was really a good experience, working with ES and IOT laboratory. First we would like to
thank Mr.K.Abdul Basith, Assoc.Professor, HOD of Department of Computer Science and
Engineering, Marri Laxman Reddy Institute of technology & Management for his concern
and giving the technical support in preparing the document.
We are deeply indebted and gratefully acknowledge the constant support and valuable
patronage of Dr. R.Kotaih, Director, Marri Laxman Reddy Institute of technology &
Management for giving us this wonderful opportunity for preparing the ES and IOT
laboratory manual.
We express our hearty thanks to Dr.K.Venkateswara Reddy, Principal, Marri Laxman Reddy
Institute of technology & Management, for timely corrections and scholarly guidance.
At last, but not the least I would like to thanks the entire CSE Department faculties those who
had inspired and helped us to achieve our goal.

GENERAL INSTRUCTIONS
 Students are instructed to come to ES and IOT laboratory on time. Late comers are not
entertained in the lab.
 Students should be punctual to the lab. If not, the conducted experiments will not be
repeated.
 Students are expected to come prepared at home with the experiments which are going to
be performed.
 Students are instructed to display their identity cards before entering into the lab.
 Students are instructed not to bring mobile phones to the lab.
 Any damage/loss of system parts like keyboard, mouse during the lab session, it is
student’s responsibility and penalty or fine will be collected from the student.
 Students should update the records and lab observation books session wise. Before leaving
the lab the student should get his lab observation book signed by the faculty.
 Students should submit the lab records by the next lab to the concerned faculty members
in thestaffroom for their correction and return.
 Students should not move around the lab during the lab session.
 If any emergency arises, the student should take the permission from faculty member
concernedin written format.
 The faculty members may suspend any student from the lab session on disciplinary
grounds.
Never copy the output from other students. Write down your own outputs.

INSTITUTION VISION AND MISSION
Vision:
To be as an ideal academic institution by graduating talented engineers to be ethically strong,
competent with quality research and technologies.
Mission:
 Utilize rigorous educational experiences to produce talented engineers
 Create an atmosphere that facilitates the success of students
 Programs that integrate global awareness, communication skills and Leadership
qualities
 Education and Research partnership with institutions and industries to prepare the
students for interdisciplinary research

DEPARTMENT VISION AND MISSION
Vision:
To empower the students to be technologically adept, innovative, self-motivated and
responsible global citizen possessing human values and contribute significantly towards
high quality technical education with ever changing world.
Mission:
 To offer high-quality education in the computing fields by providing an environment
where the knowledge is gained and applied to participate in research, for both students
and faculty.
 To develop the problem solving skills in the students to be ready to deal with cutting
edge technologies of the industry.
 To make the students and faculty excel in their professional fields by inculcating the
communication skills, leadership skills, team building skills with the organization of
various co-curricular and extra-curricular programmes.
 To provide the students with theoretical and applied knowledge, and adopt an
education approach that promotes lifelong learning and ethical growth.

PROGRAM OUTCOMES
PO
Name
Graduate
Attributes
PO Statements
PO1
Engineering
knowledge
Apply the knowledge of mathematics, science, engineering fundamentals,
and an engineering specialization to the solution of complex engineering
problems
PO 2 Problem analysis
Identify, formulate, review research literature, and analyze complex
engineering problems reaching substantiated conclusions using first
principles of mathematics, natural sciences, and engineering sciences.
PO 3
Design/
development of
solutions
Design solutions for complex engineering problems and design system
components or processes that meet the specified needs with appropriate
consideration for the public health and safety, and the cultural, societal, and
environmental considerations.
PO 4
Conduct
investigations of
complex
problems
Use research-based knowledge and research methods including design of
experiments, analysis and interpretation of data, and synthesis of the
information to provide valid conclusions
PO 5
Modern tool
usage
Create, select, and apply appropriate techniques, resources, and modern
engineering and IT tools including prediction and modeling to complex
engineering activities with an understanding of the limitations.
PO 6
The engineer and
society
Apply reasoning informed by the contextual knowledge to assess societal,
health, safety, legal and cultural issues and the consequent responsibilities
relevant to the professional engineering practice.
PO 7
Environment and
sustainability
Understand the impact of the professional engineering solutions in societal
and environmental contexts, and demonstrate the knowledge of, and need
for sustainable development.
PO 8 Ethics
Apply ethical principles and commit to professional ethics and
responsibilities and norms of the engineering practice.
PO 9
Individual and
team work
Function effectively as an individual, and as a member or leader in diverse
teams, and in multidisciplinary settings.
PO 10 Communication
Communicate effectively on complex engineering activities with the
engineering community and with society at large, such as, being able to
comprehend and write effective reports and design documentation, make
effective presentations, and give and receive clear instructions.
PO 11
Project
management and
finance
Demonstrate knowledge and understanding of the engineering and
management principles and apply these to one’s own work, as a member
and leader in a team, to manage projects and in multidisciplinary
environments.
PO 12 Life-long learning
Recognize the need for, and have the preparation and ability to engage in
independent and life-long learning in the broadest context of technological
change.

PROGRAM EDUCATIONAL OBJECTIVES
Sl. No. PEOs Name Program Education Objective Statements
1 PEO - 1
Professional career: Establish a successful professional
career in industry, government or academia
2 PEO – 2
Higher studies or R & D: gain multidisciplinary knowledge
providing a sustainable competitive edge in higher studies or
Research and Development
3 PEO – 3
Entrepreneurial: promote design, research, and
implementation of products and services through strong
communication, leadership and ethical skills, to be an
entrepreneurial

PROGRAM SPECIFIC OUTCOMES
Sl. No. PEOs Name Program Specific Outcomes
1 PSO - 1
Applications of Computing: Ability to use knowledge
in various domains to provide solution to new ideas and
innovations.
2 PSO – 2
Programming Skills: Identify required data structures,
design suitable algorithms, develop and maintain
software for real world problems.

COURSE OBJECTIVE
CO Course Objective
1 To introduce the terminology, technology and its applications
2 To introduce the concept of M2M (machine to machine) with necessary protocols
3 To introduce the Python Scripting Language which is used in many IoT devices
4 To introduce the Raspberry PI platform, that is widely used in IoT applications
5 To introduce the implementation of web-based services on IoT devices

COURSE OUTCOMES
CO Course Outcomes
CO 1 Understand the design, characteristics and technologies of Internet of Things
CO 2 Interpret the impact and challenges posed by IoT networks leading to new architectural
models.
CO 3 Compare and contrast the deployment of smart objects and the technologies to connect them
to network.
CO 4 Appraise the role of IoT protocols for efficient network communication
CO 5 Elaborate the need for Data Analytics and Security in IoT.
CO 6 Illustrate different sensor technologies for sensing real world entities and identify the
applications of IoT in Industry
COPO Mapping:
a B c d e f g h i j k l 1 2
CO 1 √ √
CO 2 √ √
CO 3 √ √ √
CO 4 √ √
CO 5 √ √
CO 6 √ √ √ √

EMBEDDED SYSTEMS & INTERNET OF THINGS LAB
(IT605PC)
1. Functional Testing Of Devices
Flashing the OS on to the device into a stable functional state by porting desktop environment
with necessary packages.
2. Exporting Display On To Other Systems
Making use of available laptop/desktop displays as a display for the device using SSH client
& X11 display server.
3. GPIO Programming
Programming of available GPIO pins of the corresponding device using native programming
language. Interfacing of I/O devices like LED/Switch etc., and testing the functionality.
4. Interfacing Chronos eZ430
Chronos device is a programmable texas instruments watch which can be used for multiple
purposes like PPT control, Mouse operations etc., Exploit the features of the device by
interfacing with devices.
5. ON/OFF Control Based On Light Intensity
Using the light sensors, monitor the surrounding light intensity & automatically turn ON/OFF
the high intensity LED's by taking some pre-defined threshold light intensity value.
6. Battery Voltage Range Indicator
Monitor the voltage level of the battery and indicating the same using multiple LED's (for ex:
for 3V battery and 3 led's, turn on 3 led's for 2-3V, 2 led's for 1-2V, 1 led for 0.1-1V & turn
off all for 0V)
7. Dice Game Simulation
Instead of using the conventional dice, generate a random value similar to dice value and
display the same using a 16X2 LCD. A possible extension could be to provide the user with
option of selecting single or double dice game.
8. Displaying RSS News Feed On Display Interface
Displaying the RSS news feed headlines on a LCD display connected to device. This can be
adapted to other websites like twitter or other information websites. Python can be used to
acquire data from the internet.
9. Porting Openwrt To the Device
Attempt to use the device while connecting to a wifi network using a USB dongle and at the
same time providing a wireless access point to the dongle.

10. Hosting a website on Board
Building and hosting a simple website(static/dynamic) on the device and make it accessible
online. There is a need to install server(eg: Apache) and thereby host the website.
11. Webcam Server
Interfacing the regular usb webcam with the device and turn it into fully functional IP
webcam & test the functionality.
12. FM Transmission
Transforming the device into a regular fm transmitter capable of transmitting audio at desired
frequency (generally 88-108 Mhz)
Note: Devices mentioned in the above lists include Arduino, Raspbery Pi, Beaglebone

Experiment - 1
Functional Testing of Devices
Flashing the OS on to the device into a stable functional state by porting
desktop environment with necessary packages.
Raspberry Pi
You are going to take a first look at Raspberry Pi! You should have a Raspberry Pi computer
in front of you for this. The computer shouldn’t be connected to anything yet.
o Look at your Raspberry Pi. Can you find all the things labelled on the diagram?
 USB ports — these are used to connect a mouse and keyboard. You can also connect
other components, such as a USB drive.
 SD card slot — you can slot the SD card in here. This is where the operating system
software and your files are stored.
 Ethernet port — this is used to connect Raspberry Pi to a network with a cable.
Raspberry Pi can also connect to a network via wireless LAN.
 Audio jack — you can connect headphones or speakers here.

 HDMI port — this is where you connect the monitor (or projector) that you are using
to display the output from the Raspberry Pi. If your monitor has speakers, you can also
use them to hear sound.
 Micro USB power connector — this is where you connect a power supply. You should
always do this last, after you have connected all your other components.
 GPIO ports — these allow you to connect electronic components such as LEDs and
buttons to Raspberry Pi.
Set up your SD card
If you have an SD card that doesn’t have the Raspberry Pi OS operating system on it yet, or if
you want to reset your Raspberry Pi, you can easily install Raspberry Pi OS yourself. To do
so, you need a computer that has an SD card port — most laptop and desktop computers have
one.
The Raspberry Pi OS operating system via the Raspberry Pi Imager
Using the Raspberry Pi Imager is the easiest way to install Raspberry Pi OS on your SD card.
Note: More advanced users looking to install a particular operating system should use this
guide to installing operating system images.
Download and launch the Raspberry Pi Imager
o Visit the Raspberry Pi downloads page
o Click on the link for the Raspberry Pi Imager that matches your operating system

o When the download finishes, click it to launch the installer
Using the Raspberry Pi Imager
Anything that’s stored on the SD card will be overwritten during formatting. If your SD card
currently has any files on it, e.g. from an older version of Raspberry Pi OS, you may wish to
back up these files first to prevent you from permanently losing them.
When you launch the installer, your operating system may try to block you from running it.
For example, on Windows I receive the following message:

 If this pops up, click on More info and then Run anyway
 Follow the instructions to install and run the Raspberry Pi Imager
 Insert your SD card into the computer or laptop SD card slot
 In the Raspberry Pi Imager, select the OS that you want to install and the SD card you
would like to install it on
Note: You will need to be connected to the internet the first time for the the Raspberry Pi
Imager to download the OS that you choose. That OS will then be stored for future offline
use. Being online for later uses means that the Raspberry Pi imager will always give you the
latest version.

 Then simply click the WRITE button
 Wait for the Raspberry Pi Imager to finish writing
 Once you get the following message, you can eject your SD card
Connect your Raspberry Pi
Let’s connect up your Raspberry Pi and get it running.
o Check the slot on the underside of your Raspberry Pi to see whether an SD card is inside.
If no SD card is there, then insert an SD card with Raspbian installed (via NOOBS).

Note: Many microSD cards come inside a larger adapter — you can slide the smaller card out
using the lip at the bottom.
o Find the USB connector end of your mouse’s cable, and connect the mouse to a USB port
on your Raspberry Pi (it doesn’t matter which port you use).
o Connect the keyboard in the same way.
o Make sure your screen is plugged into a wall socket and switched on.
o Look at the HDMI port(s) on your Raspberry Pi — notice that they have a flat side on top.

o Use a cable to connect the screen to the Raspberry Pi’s HDMI port — use an adapter if
necessary.
Raspberry Pi 4
Connect your screen to the first of Raspberry Pi 4’s HDMI ports, labelled HDMI0.
You could connect an optional second screen in the same way.
Raspberry Pi 1, 2, 3
Connect your screen to the single HDMI port.

Note: nothing will display on the screen, because the Raspberry Pi is not running yet.
o If you want to connect the Pi to the internet via Ethernet, use an Ethernet cable to connect
the Ethernet port on the Raspberry Pi to an Ethernet socket on the wall or on your internet
router. You don’t need to do this if you want to use wireless connectivity, or if you don’t
want to connect to the internet.
o If your screen has speakers, your Raspberry Pi can play sound through these. Or you could
connect headphones or speakers to the audio port.

Start up your Raspberry Pi
Your Raspberry Pi doesn’t have a power switch. As soon as you connect it to a power outlet,
it will turn on.
o Plug the power supply into a socket and connect it to your Raspberry Pi’s power port.
You should see a red LED light up on the Raspberry Pi, which indicates that Raspberry Pi is
connected to power. As it starts up (this is also called booting), you will see raspberries
appear in the top left-hand corner of your screen.
After a few seconds the Raspberry Pi OS desktop will appear.

Finish the setup
When you start your Raspberry Pi for the first time, the Welcome to Raspberry Pi application
will pop up and guide you through the initial setup.
 Click Next to start the setup.
 Set your Country, Language, and Timezone, then click Next again.

o Enter a new password for your Raspberry Pi and click Next.
o Connect to your WiFi network by selecting its name, entering the password, and
clicking Next.

Note: if your Raspberry Pi model doesn’t have wireless connectivity, you won’t see this
screen.
o Click Next let the wizard check for updates to Raspbian and install them (this might take a
little while).
o Click Done or Reboot to finish the setup.
Note: you will only need to reboot if that’s necessary to complete an update.

A tour of Raspberry Pi
Now it’s time to take a tour of your Raspberry Pi.
o Do you see the raspberry symbol in the top left-hand corner? That’s where you access the
menu: click on it to find lots of applications.
o Click on Accessories, and then click on Text Editor.

o Type I just built a Raspberry Pi computer in the window that appears.
o Click on File, then choose Save, and then click on Desktop and save the file as rp.txt.
o You should see an icon named rp.txt appear on the desktop.

Your file has been saved to your Raspberry Pi’s SD card.
 Close the text editor by clicking the X in the top right-hand corner of the window.
 Return to the menu, click on Shutdown, and then click on Reboot.
 When Raspberry Pi has rebooted, your text file should still be there on the desktop.
 Raspberry Pi runs a version of an operating system called Linux (Windows and
macOS are other operating systems). This operating system allows you to make things
happen by typing in commands instead of clicking on menu options. To try this out,
click on the Terminal symbol at the top of the screen:
o In the window that appears, type:

ls
and then press Enter on the keyboard.
You can now see a list of the files and folders in your home directory.
o Now type this command to change directory to the Desktop:
cd Desktop
You have to press the Enter key after every command.
Then type:
ls
Can you see the text file you created?
o Close the terminal window by clicking on the X.
o Now drag rp.txt to the Wastebasket on the desktop so the Raspberry Pi will be tidy for the
next person using it.
Browsing the web
You might want to connect your Raspberry Pi to the internet. If you didn’t plug in an ethernet
cable or connect to a WiFi network during the setup, then you can connect now.
o Click the icon with red crosses in the top right-hand corner of the screen, and select your
network from the drop-down menu. You may need to ask an adult which network you
should choose.

o Type in the password for your wireless network, or ask an adult to type it for you, then
click OK.
o When your Pi is connected to the internet, you will see a wireless LAN symbol instead of
the red crosses.
o Click the web browser icon and search for raspberry pi.
Configuring your Raspberry Pi
You can control most of your Raspberry Pi’s settings, such as the password, through
the Raspberry Pi Configuration application found in Preferences on the menu.

 System
In this tab you can change basic system settings of your Raspberry Pi.
 Password — set the password of the pi user (it is a good idea to change the password
from the factory default ‘raspberry’)
 Boot — select to show the Desktop or CLI (command line interface) when your
Raspberry Pi starts
 Auto Login — enabling this option will make the Raspberry Pi automatically log in
whenever it starts

 Network at Boot — selecting this option will cause your Raspberry Pi to wait until a
network connection is available before starting
 Splash Screen — choose whether or not to show the splash (startup) screen when your
Raspberry Pi boots
 Interfaces
You can link devices and components to your Raspberry Pi using a lot of different types of
connections. The Interfaces tab is where you turn these different connections on or off, so
that your Raspberry Pi recognises that you’ve linked something to it via a particular type of
connection.
 Camera — enable the Raspberry Pi Camera Module
 SSH — allow remote access to your Raspberry Pi from another computer using
SSH
 VNC — allow remote access to the Raspberry Pi Desktop from another computer
using VNC
 SPI — enable the SPI GPIO pins
 I2C — enable the I2C GPIO pins
 Serial — enable the Serial (Rx, Tx) GPIO pins
 1-Wire — enable the 1-Wire GPIO pin
 Remote GPIO — allow access to your Raspberry Pi’s GPIO pins from another
computer

 Performance
If you need to do so for a particular project you want to work on, you can change the
performance settings of your Raspberry Pi in this tab.
Warning: Changing your Raspberry Pi’s performance settings may result in it behaving
erratically or not working.
 Overclock — change the CPU speed and voltage to increase performance
 GPU Memory — change the allocation of memory given to the GPU
 Localisation
This tab allows you to change your Raspberry Pi settings to be specific to a country or
location.
 Locale — set the language, country, and character set used by your Raspberry Pi

 Timezone — set the time zone
 Keyboard — change your keyboard layout
 WiFi Country — set the WiFi country code

Experiment - 2
Exporting Display On To Other Systems
Making use of available laptop/desktop displays as a display for the device using SSH
client & X11 display server.
How Does it Work?
To connect a Raspberry Pi to a laptop display, you can simply use an Ethernet cable. The
Raspberry Pi’s desktop GUI (Graphical User Interface) can be viewed through the laptop
display using a 100 Mbps Ethernet connection between the two. There are many software
programs available that can establish a connection between a Raspberry Pi and your laptop.
We used VNC server software to connect the Pi to our laptop. Installing the VNC server on
your Pi allows you to see the Raspberry Pi’s desktop remotely, using the mouse and keyboard
as if you were sitting right in front of your Pi. It also means that you can put your Pi
anywhere else in your home and still control it. Also, the internet can be shared from your
laptop’s WiFi over Ethernet. This also lets you access the internet on the Pi and connect it to
your laptop display.
Setting up your Raspberry Pi
Before moving to connect your Raspberry Pi to your laptop display, you need an SD card
with the OS preinstalled, or install Raspbian on a blank SD card. You will find lots of blogs
and tutorials on preparing an SD card for the Raspberry Pi. If you are a beginner, you can
simply click hereand know more about this. This will show how to install the OS for the
Raspberry Pi. You can also buy SD cards with the Raspbian and NOOBs operating systems
preinstalled. I would suggest you install the latest full Raspbian OS image from the official
Raspberry Pi website as it is having VNC Server in the OS package.
After setting up your SD Card, insert it into the Raspberry Pi. Next, connect your power
adapter to the Raspberry Pi to power it. Also, connect your Raspberry Pi to the laptop via an
Ethernet cable and connect a keyboard and mouse to it.
Note: You need screen and a mouse after booting a new OS into Pi for the first time as by
default, the SSH and VNC are disabled in Pi. Without SSH disabled, we cannot enable the
PuTTY Configuration.

Sharing Internet Over Ethernet
This step explains how you can share your laptop internet with the Raspberry Pi via Ethernet
cable. In Windows: To share the internet with multiple users over Ethernet, go to Network
and Sharing Center. Then click on the WiFi network:
Click on Properties (shown below), then go to Sharing and click on “Allow other network
users to connect”. Make sure that the networking connection is changed to the connection of
the Raspberry Pi. In my case, it is Ethernet:

Finding IP for PuTTY Configuration
By default, the laptop will give a dynamic IP to the Raspberry Pi. Thus, we have to find out
the IP address of Pi now.
As shown above, the IP assigned to my Pi is 192.168.137.144. To check the IP assigned to
the connected Ethernet device, do the following. Considering that the IP assigned to your Pi
is 192.168.137.144 and the subnet mask is 255.255.255.0 :

 Open the command prompt.
 Ping at raspberrypi.mshome.net.
 Stop the ping after 5 seconds.
Here, it is 192.168.137.154. Note this somewhere.
PuTTY Configuration and VNC on Raspberry Pi

 In the Host Name, enter the IP Address we noted from the command line.
 Ensure that the Connection Type is SSH.
 Hit Enter or click on Open to proceed.
 Now, a new window will open. It looks like a normal terminal window of the computer but
it is Raspberry Pi's terminalwindow accessible on your laptop.
 It is display- login as:
 Enter pi as the username.
 Enter the password you set for the Raspberry Pi. The default password is raspberry
 If the password is correct, the Pi will load and you will access the terminal window of the
Pi.
 Now, you need to start the VNC Server. Enter after the $ sign - sudo vncserver :1
 This is to initialize the VNC Server on the Raspberry Pi.
VNC Server and VNC Viewer on Laptop
Now, Raspberry is ready to connect using VNC. We just need to install the VNC server on
the laptop.
 Download VNC Client and install it. Now, download the VNC Viewerand install it on the
laptop.
 Open the VNC Server and the VNC Viewer now.
 In the VNC Viewer, click on File > New Connection.
 Enter IP Address and in Options > Picture Quality, select High.

 Click OK. Now, double click on the IP Address.
 Enter pi in Username and your Pi's password (default is raspberry).
 Click on Remember Password so that you don't have to enter this next time.
 Click on OK.

As you hit enter and all the things are correct, the Raspberry Pi Desktop will load in a new
window. You can go into a full-screen mode by clicking on the options available above on
the window.

Experiment - 3
GPIO Programming
Programming of available GPIO pins of the corresponding device using native
programming language. Interfacing of I/O devices like LED/Switch etc., and testing the
functionality.
GPIO Pins :
As shown in above figure, there are 40output pins for the PI. But when you look at the second
figure, you can see not all 40 pin out can be programmed to our use. These are only 26 GPIO
pins which can be programmed. These pins go from GPIO2 to GPIO27.
These 26 GPIO pins can be programmed as per need. Some of these pins also perform
some special functions, we will discuss about that later. With special GPIO put aside, we
have 17 GPIO remaining (Light green Cirl).
Each of these 17 GPIO pins can deliver a maximum of 15mA current. And the sum of
currents from all GPIO cannot exceed 50mA. So we can draw a maximum of 3mA in average

from each of these GPIO pins. So one should not tamper with these things unless you know
what you are doing.
Components Required
Here we are using Raspberry Pi 2 Model B with Raspbian Jessie OS. All the basic
Hardware and Software requirements are previously discussed, you can look it up in
the Raspberry Pi Introduction, other than that we need:
 Connecting pins
 220Ω or 1KΩresistor
 LED
 Bread Board
Circuit Diagram:

Steps:
1. On the desktop, go the Start Menu and choose for the PYTHON 3, as shown in figure
below.
2. After that, PYHON will run and you will see a window as shown in below figure.

3. After that, click on New File in File Menu, You will see a new Window open,
4. Save this file as blinky on the desktop,

5. After that write the program for blinky as given below and execute the program by clicking
on “RUN” on ‘DEBUG’ option.
If the program has no errors in it, you will see a “>>>”, which means the program is executed
successfully. By this time you should see the LED blinking three times. If there were any
errors in the program, the execution tells to correct it. Once the error is corrected execute the
program again.

Program:
from gpiozero import LED
from time import sleep
led = LED(17)
while True:
led.on()
sleep(1)
led.off()
sleep(1)

Experiment – 4
Interfacing Chronos eZ430
Chronos device is a programmable texas instruments watch which can be used for multiple
purposes like PPT control, Mouse operations etc., Exploit the features of the device by
interfacing with devices.
Using the eZ430 Chronos with a Raspberry Pi
The eZ430 Chronos development kit from Texas Instruments represents great value for
money and provides a wristwatch with a wireless-enabled microcontroller, accelerometers
and temperature and barometric pressure sensors, and a USB programmer and RF access
point. In this post I take a look at what it takes to get it up and running with a Raspberry Pi.
The Chronos RF access point simply presents itself as a serial port to the operating system
and drivers are included in Linux, and so any heavy lifting in enabling communications
between the watch and host has already been done for us.
With the access point plugged into the Raspberry Pi USB we just need to install a few
dependencies in order to run the TI supplied demonstration software and a simple example

Python script. Assuming that you are running Debian Linux this can be achieved using the
command:
$ sudo apt-get install python-serial tcl8.5 tk8.5 xdotool
Chronos Control Center
Chronos Control Center is a GUI tool that provides a selection of applications which
demonstrate the capabilities of the eZ430 Chronos. The Linux version of the software must
have been developed with x86 architecture in mind as it's provided as a binary installer rather
than a tar archive. However, since it's Tcl/Tk based it should run on just about any
platform/architecture for which this software is available. It's trivial to repackage it so that it's
not architecture-specific, and this just requires access to an Intel/AMD Linux machine on
which to run the following commands:
$ unzip slac388a.zip
$ ./Chronos-Setup
$ tar zcvf ccc.tgz ~/Texas Instruments/eZ430-Chronos
Obviously if you installed the software to a location other than the default as part of the
second step, you will need to use that location for the second argument in the third step. The
ccc.tgz archive can then be copied to the Raspberry Pi and unpacked to a suitable location.
Control Center software running, with the access point enabled and the watch set
to ACC mode and with RF enabled. Real-time data from the watch accelerometers is
displayed, and by selecting Mouse On it's also possible to use the watch to control the
Raspberry Pi mouse pointer through gesture. As can be seen the Control Center provides a
number of other simple applications that can be selected via the tabs at the top.
Setting the time via a Python script
It should be possible to write host-based applications for the Chronos in just about any
language that provides access to serial devices. When using the Python language this is
achieved via the pySerial library, and with a reasonably short script it's possible to

configure the serial port, send the commands required to start up the RF access point, and
then get the Raspberry Pi system time, format this into packets, transmit them to the watch
and set the time accordingly.
Note that if you do wish to make use of the linked script you will need to change the line that
configures the serial port parameters to read:
ser = serial.Serial('/dev/ttyACM0',115200,timeout=1)
Conclusion
Together the Chronos eZ430 and Raspberry Pi opens up all sorts of exciting possibilities,
where data can be sourced from the watch sensors or the Internet, processed and pushed in
either direction. With the relatively powerful processing capabilities of the Raspberry Pi
being made use of, and its hardware capabilities further extended via the GPIO port. As such
it would seem like a winning combination for low cost experimentation with wearable and
ubiquitous computing. And with a little enhanced support from within the Python language, it
is easy to see how the Chronos could become an incredibly fun accessory to Raspberry Pi-
based learning in schools.


Experiment - 5
ON/OFF Control Based On Light Intensity
Using the light sensors, monitor the surrounding light intensity & automatically turn
ON/OFF the high intensity LED's by taking some pre-defined threshold light intensity
value.
Measure the intensity of light in a room using a single photocell and a capacitor connected to
the raspberry pi with a bit of code in python.
What is Photocell?
The Photocell is a light sensor in which the resistance varies according to the intensity of
light. The resistance reduces when it is in brighter surroundings. We have to set up a
threshold value for the measurements of the intensity because it cannot give the precise
measurements. If the measurements are below the threshold then it is dark, else it is bright.
Role of a Capacitor
A Capacitor is an electrical component that can store electrical energy temporarily. It is
measured in Farads which is characterized by capacitance. The capacitor consists of 2
conductors that can hold the electric charge and when it is fully charged the capacitor starts
discharging. This kind of alternative behavior is used to generate AC.

When the switch is pressed the current starts flowing and the capacitor starts charging up.
The capacitor stops charging when the voltage at its end reaches the voltage of the battery.
Then as there is no potential difference in the upper half of the circuit, no current flows there.
Things needed
 A Raspberry pi
 1 x breadboard
 A Photocell
 A Resistor
 A Capacitor ( 1 microfarad)
Circuit:
We need to measure the resistance of the photoresistor. The Raspberry pi acts as the battery
whereas the GPIO pin 1 provides 3.3 V to the photoresistor. Make the GPIO pin 12 as the
bidirectional pin ( input and output pin). When the capacitor is charging it will take some
time to reach a voltage that registers as high. GPIO pin 6 is grounded which is connected
to the negative side of the capacitor (short end). Check how long it takes for the input pin to
become high and use the result to calculate the resistance of the photocell.

 Insert a photocell in a breadboard.
 Connect the GPIO pin 1 (3.3 V) to the resistor which is connected serial to the
Photocell.
 Connect the other end of the photocell to the GPIO pin 12 and the Capacitor as shown
in the diagram.
 GPIO pin 6 ( ground) is connected to the other end of the capacitor ( short end ).
Code
#measuring the light intensity using a photocell
import RPi.GPIO as GPIO,time,os #import the libraries
DEBUG=1
GPIO.setmode(GPIO.BOARD)
GPIO.setwarnings(False)
def RCtime(RCpin): # function start
reading=0
GPIO.setup(RCpin,GPIO.OUT)
GPIO.output(RCpin,GPIO.LOW)
time.sleep(2) # time to discharge capacitor
GPIO.setup(RCpin,GPIO.IN)
while (GPIO.input(RCpin) == GPIO.LOW):
# the loop will run till the capacitor is charged
reading += 1
# measuring time which in turn is measuring resistance
return reading
# function

while True:
print RCtime(12) # calling the function
Output
1. With light:
2. Without light:

Experiment - 6
Battery Voltage Range Indicator
Monitor the voltage level of the battery and indicating the same using multiple LED's
(for ex: for 3V battery and 3 led's, turn on 3 led's for 2-3V, 2 led's for 1-2V, 1 led for
0.1-1V & turn off all for 0V)
Battery Voltage Indicator using Arduino and LED Bar Graph
Batteries come with a certain voltage limit and if the voltage goes beyond the prescribed
limits while charging or discharging, the life of the battery get affected or reduced. Whenever
we use a battery powered project, sometimes we need to check the battery voltage level,
whether it is needed to be charged or replaced. This circuit will help you to monitor the
voltage of your battery. This Arduino battery voltage indicator indicates the status of the
battery by glowing LEDs on a 10 Segment LED Bar Graph according to the battery
voltage. It also shows your battery voltage on the LCD connected to the Arduino.
Material Required
 Arduino UNO
 10 Segment LED Bar Graph
 LCD (16*2)
 Potentiometer-10k
 Resistor (100ohm-10;330ohm)
 Battery (to be tested)
 Connecting wires
 12v adapter for Arduino

LED Bar Graph
The LED bar graph comes in industrial standard size with a low power consumption. The bar is
categorized for luminous intensity. The product itself remains within RoHS compliant version. It
has a forward voltage of up to 2.6v. The power dissipation per segment is 65mW. The operating
temperature of the LED bar graph is -40℃ to 80℃. There are many application for the LED bar
graph like Audio equipment, Instrument panels, and Digital readout display.
Pin Diagram
Pin Configuration

Working of Battery Voltage Indicator
Battery Voltage Indicator just read the value from Arduino Analog pin and convert it into a
digital value by using the Analog to Digital Conversion (ADC) formula. The Arduino Uno
ADC is of 10-bit resolution (so the integer values from 0 - 2^10 = 1024 values). This means
that it will map input voltages between 0 and 5 volts into integer values between 0 and 1023.
So if we multiply input anlogValue to (5/1024), then we get the digital value of input voltage.
Learn here how to use ADC input in Arduino. Then the digital value is used to glow the LED
bar Graph accordingly.
CODE:
#include <LiquidCrystal.h>
const int rs = 12, en = 13, d0 = A0, d1 = A1, d2 = A2, d3 = A3;
LiquidCrystal lcd(rs, en, d0, d1, d2, d3);
const int analogPin = A4;
float analogValue;
float input_voltage;
int ledPins[] = {
2, 3, 4, 5, 6, 7, 8, 9, 10, 11
}; // an array of pin numbers to which LEDs are attached
int pinCount = 10; // the number of pins (i.e. the length of the array)
void setup()
{
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
lcd.begin(16, 2); //// set up the LCD's number of columns and rows:
pinMode(A0,OUTPUT);
pinMode(A1,OUTPUT);

pinMode(A2,OUTPUT);
pinMode(A3,OUTPUT);
pinMode(A4,INPUT);
lcd.print("Voltage Level");
}
void LED_function(int stage)
{
for (int j=2; j<=11; j++)
{
digitalWrite(j,LOW);
}
for (int i=1, l=2; i<=stage; i++,l++)
{
digitalWrite(l,HIGH);
//delay(30);
}
}
void loop()
{
// Conversion formula for voltage
analogValue = analogRead (A4);
Serial.println(analogValue);
delay (1000);
input_voltage = (analogValue * 5.0) / 1024.0;
lcd.setCursor(0, 1);
lcd.print("Voltage= ");
lcd.print(input_voltage);
Serial.println(input_voltage);
delay(100);
if (input_voltage < 0.50 && input_voltage >= 0.00 )
{
digitalWrite(2, HIGH);
delay (30);
digitalWrite(2, LOW);
delay (30);
}
else if (input_voltage < 1.00 && input_voltage >= 0.50)
{
LED_function(2);
}
{
LED_function(3);
}
{
LED_function(4);
}
{

LED_function(5);
}
{
LED_function(6);
}
{
LED_function(7);
}
{
LED_function(8);
}
{
LED_function(9);
}
{
LED_function(10);
}
}

Experiment - 7
Dice Game Simulation
Instead of using the conventional dice, generate a random value similar to dice value
and display the same using a 16X2 LCD. A possible extension could be to provide the
user with option of selecting single or double dice game.
#include <LiquidCrystal.h>
long randNumber;
int Led = 13; //define LED port
int Shock = 2; //define shock port
int val;//define digital variable val
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 8, 9, 10, 11, 12 );
byte customChar[] = {
B00000,
B00000,
B11111,
B11001,
B10101,
B10011,

B11111,
B00000
};
void setup()
{
lcd.begin(16, 2);
lcd.createChar(0, customChar);
lcd.home();
pinMode(Led, OUTPUT); //define LED as a output port
randomSeed(analogRead(0));
pinMode(Shock, INPUT); //define shock sensor as a output port
lcd.write(byte( 0));
lcd.print("Digital dice");
lcd.write(byte( 0));
delay(1000);
}
void loop()
{
val = digitalRead(Shock); //read the value of the digital interface 3 assigned to val
if (val == LOW) //when the shock sensor have signal do the following
{
lcd.clear();
lcd.print("Rolling dice...");
delay(4000);
lcd.clear();
randNumber = random(1,7);
lcd.print("Dice 1 = ");
lcd.print(randNumber);
randNumber = random(1,7);

lcd.print("Dice 2 = ");
lcd.print(randNumber);
}
delay(150);
}

Experiment - 8
Displaying RSS News Feed On Display Interface
Displaying the RSS news feed headlines on a LCD display connected to device. This can
be adapted to other websites like twitter or other information websites. Python can be
used to acquire data from the internet.
Keeping up to date with the latest news is tough and sometimes we need a little help. RSS
feeds provide a great way to quickly digest lots of news quickly. Sure you could visit an RSS
feed or have an RSS reader on your computer, but what if you could have a simple, dedicated
device that only shows the headlines?
Here’s a Raspberry Pi project that will use Python code to read an RSS feed, the Tom’s
Hardware feed for example, and display the top five headlines on an LCD screen.
To build this project you will need:
 Any model of Raspberry Pi with Raspberry Pi OS and GPIO Pins
 An I2C LCD screen such as this one
 4 x Female to female jumper wires
1. Install Python libraries to use LCD screens and work with RSS feeds by entering the
following commands:
sudo pip3 install rpi-lcd feedparser
2. Enable the I2C interface via Preferences >> Raspberry Pi Configuration

3. Connect the I2C LCD screen as per the diagram.
4. Launch Thonny. You can find it on the start menu under Programming.
5. In a new file import libraries of Python code to use the LCD screen, control the pace of
the project, read the RSS feed and finally manipulate text into chunks.

from rpi_lcd import LCD
import feedparser
import textwrap
6. Create an object, called “tom” which will store the RSS feed data from Tom’s
Hardware.
tom = feedparser.parse("https://www.tomshardware.com/uk/feeds/all")
7. Create a connection to the LCD and then pause the code for 1 second.
lcd = LCD()
sleep(1)
8. Use a for loop to repeat code five times. If you want more than 5 headlines, change the (5)
to a higher number.
for i in range(5):
9. Print the entries from the Tom’s Hardware RSS feed. The value of i is incremented
each time the for loop goes round, to a maximum of five.
print(tom['entries'][i]['title'])
10. Create an object called split and use that to save 16 character chunks of the RSS feed.
The chunk size is set by the 16 character screen size of the LCD.
split = textwrap.wrap(text, 16)
11. Create an object called split and use that to save 16 character chunks of the RSS feed.
The chunk size is set by the 16 character screen size of the LCD.
12. Print “Tom’s Hardware” (or the name of your news source) to the first line of the
LCD screen.
lcd.text("Tom's Hardware", 1)
13. Create another for loop to print the contents of the split object to the LCD screen.
for i in range(len(split)):

lcd.text(split[i], 2)
sleep(0.5)
14. Add a one second pause before clearing the LCD screen.
sleep(1)
lcd.clear()
15. Save the code as TomsRSSFeed.py
Code:
from rpi_lcd import LCD
import feedparser
import textwrap
tom = feedparser.parse("https://www.tomshardware.com/uk/feeds/all")
lcd = LCD()
sleep(5)
for i in range(5):
print(tom['entries'][i]['title'])
text = tom['entries'][i]['title']
lcd.text("Tom's Hardware", 1)
for i in range(len(split)):
lcd.text(split[i], 2)
sleep(0.5)
sleep(1)
lcd.clear()

Experiment - 9
Porting Openwrt
To the Device Attempt to use the device while connecting to a wifi network using a USB
dongle and at the same time providing a wireless access point to the dongle.
Setting up a Raspberry Pi as a routed wireless access point
A Raspberry Pi within an Ethernet network can be used as a wireless access point, creating a
secondary network. The resulting new wireless network is entirely managed by the Raspberry
Pi.
If you wish to extend an existing Ethernet network to wireless clients, consider instead setting
up a bridged access point.
A routed wireless access point can be created using the inbuilt wireless features of the
Raspberry Pi 4, Raspberry Pi 3 or Raspberry Pi Zero W, or by using a suitable USB wireless
dongle that supports access point mode. It is possible that some USB dongles may need slight
changes to their settings. If you are having trouble with a USB wireless dongle, please check
the forums.
This documentation was tested on a Raspberry Pi 3B running a fresh installation of Raspberry
Pi OS Buster.
Before we start

 Ensure you have administrative access to your Raspberry Pi. The network setup will
be modified as part of the installation: local access, with screen and keyboard
connected to your Raspberry Pi, is recommended.
 Connect your Raspberry Pi to the Ethernet network and boot the Raspberry Pi OS.
 Ensure the Raspberry Pi OS on your Raspberry Pi is up-to-date and reboot if packages
were installed in the process.
 Take note of the IP configuration of the Ethernet network the Raspberry Pi is
connected to:
o In this document, we assume IP network 10.10.0.0/24 is configured on the
Ethernet LAN, and the Raspberry Pi is going to manage IP
network 192.168.4.0/24 for wireless clients.
o Please select another IP network for wireless, e.g. 192.168.10.0/24 , if IP
network 192.168.4.0/24 is already in use by your Ethernet LAN.
 Have a wireless client (laptop, smartphone, ...) ready to test your new access point.
Install the access point and network management software
In order to work as an access point, the Raspberry Pi needs to have the hostapd access point
software package installed:
sudo apt install hostapd
Enable the wireless access point service and set it to start when your Raspberry Pi boots:
sudo systemctl unmask hostapd
sudo systemctl enable hostapd
In order to provide network management services (DNS, DHCP) to wireless clients, the
Raspberry Pi needs to have the dnsmasq software package installed:
sudo apt install dnsmasq
Finally, install netfilter-persistent and its plugin iptables-persistent . This utilty helps by
saving firewall rules and restoring them when the Raspberry Pi boots:

sudo DEBIAN_FRONTEND=noninteractive apt install -y netfilter-persistent iptables-
persistent
Software installation is complete.
Set up the network router
The Raspberry Pi will run and manage a standalone wireless network. It will also route
between the wireless and Ethernet networks, providing internet access to wireless clients. If
you prefer, you can choose to skip the routing by skipping the section "Enable routing and IP
masquerading" below, and run the wireless network in complete isolation.
Define the wireless interface IP configuration
The Raspberry Pi runs a DHCP server for the wireless network; this requires static IP
configuration for the wireless interface ( wlan0 ) in the Raspberry Pi. The Raspberry Pi also
acts as the router on the wireless network, and as is customary, we will give it the first IP
address in the network: 192.168.4.1 .
To configure the static IP address, edit the configuration file for dhcpcd with:
sudo nano /etc/dhcpcd.conf
Go to the end of the file and add the following:
interface wlan0
static ip_address=192.168.4.1/24
nohook wpa_supplicant
Enable routing and IP masquerading
This section configures the Raspberry Pi to let wireless clients access computers on the main
(Ethernet) network, and from there the internet. NOTE: If you wish to block wireless clients
from accessing the Ethernet network and the internet, skip this section.
To enable routing, i.e. to allow traffic to flow from one network to the other in the Raspberry
Pi, create a file using the following command, with the contents below:
sudo nano /etc/sysctl.d/routed-ap.conf

File contents:
# https://www.raspberrypi.org/documentation/configuration/wireless/access-point-routed.md
# Enable IPv4 routing
net.ipv4.ip_forward=1
Enabling routing will allow hosts from network 192.168.4.0/24 to reach the LAN and the
main router towards the internet. In order to allow traffic between clients on this foreign
wireless network and the internet without changing the configuration of the main router, the
Raspberry Pi can substitute the IP address of wireless clients with its own IP address on the
LAN using a "masquerade" firewall rule.
 The main router will see all outgoing traffic from wireless clients as coming from the
Raspberry Pi, allowing communication with the internet.
 The Raspberry Pi will receive all incoming traffic, substitute the IP addresses back,
and forward traffic to the original wireless client.
This process is configured by adding a single firewall rule in the Raspberry Pi:
sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
Now save the current firewall rules for IPv4 (including the rule above) and IPv6 to be loaded
at boot by the netfilter-persistent service:
sudo netfilter-persistent save
Filtering rules are saved to the directory /etc/iptables/ . If in the future you change the
configuration of your firewall, make sure to save the configuration before rebooting.
Configure the DHCP and DNS services for the wireless network
The DHCP and DNS services are provided by dnsmasq . The default configuration file
serves as a template for all possible configuration options, whereas we only need a few. It is
easier to start from an empty file.
Rename the default configuration file and edit a new one:
sudo mv /etc/dnsmasq.conf /etc/dnsmasq.conf.orig

sudo nano /etc/dnsmasq.conf
Add the following to the file and save it:
interface=wlan0 # Listening interface
dhcp-range=192.168.4.2,192.168.4.20,255.255.255.0,24h
# Pool of IP addresses served via DHCP
domain=wlan # Local wireless DNS domain
address=/gw.wlan/192.168.4.1
# Alias for this router
The Raspberry Pi will deliver IP addresses between 192.168.4.2 and 192.168.4.20 , with a
lease time of 24 hours, to wireless DHCP clients. You should be able to reach the Raspberry
Pi under the name gw.wlan from wireless clients.
There are many more options for dnsmasq ; see the default configuration file
( /etc/dnsmasq.conf ) or the online documentation for details.
Ensure wireless operation
Countries around the world regulate the use of telecommunication radio frequency bands to
ensure interference-free operation. The Linux OS helps users comply with these rules by
allowing applications to be configured with a two-letter "WiFi country code", e.g. US for a
computer used in the United States.
In the Raspberry Pi OS, 5 GHz wireless networking is disabled until a WiFi country code has
been configured by the user, usually as part of the initial installation process (see wireless
configuration pages in this section for details.)
To ensure WiFi radio is not blocked on your Raspberry Pi, execute the following command:
sudo rfkill unblock wlan
This setting will be automatically restored at boot time. We will define an appropriate
country code in the access point software configuration, next.
Configure the access point software

Create the hostapd configuration file, located at /etc/hostapd/hostapd.conf , to add the
various parameters for your new wireless network.
sudo nano /etc/hostapd/hostapd.conf
Add the information below to the configuration file. This configuration assumes we are using
channel 7, with a network name of NameOfNetwork , and a
password AardvarkBadgerHedgehog . Note that the name and password should not have
quotes around them. The passphrase should be between 8 and 64 characters in length.
country_code=GB
interface=wlan0
ssid=NameOfNetwork
hw_mode=g
channel=7
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=AardvarkBadgerHedgehog
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
Note the line country_code=GB : it configures the computer to use the correct wireless
frequencies in the United Kingdom. Adapt this line and specify the two-letter ISO code of
your country. See Wikipedia for a list of two-letter ISO 3166-1 country codes.
To use the 5 GHz band, you can change the operations mode
from hw_mode=g to hw_mode=a . Possible values for hw_mode are:
 a = IEEE 802.11a (5 GHz) (Raspberry Pi 3B+ onwards)
 b = IEEE 802.11b (2.4 GHz)
 g = IEEE 802.11g (2.4 GHz)
Note that when changing the hw_mode , you may need to also change the channel -
see Wikipedia for a list of allowed combinations.

Run your new wireless access point
Now restart your Raspberry Pi and verify that the wireless access point becomes
automatically available.
sudo systemctl reboot
Once your Raspberry Pi has restarted, search for wireless networks with your wireless client.
The network SSID you specified in file /etc/hostapd/hostapd.conf should now be present,
and it should be accessible with the specified password.
If SSH is enabled on the Raspberry Pi, it should be possible to connect to it from your
wireless client as follows, assuming the pi account is present: ssh pi@192.168.4.1 or ssh
pi@gw.wlan
If your wireless client has access to your Raspberry Pi (and the internet, if you set up
routing), congratulations on setting up your new access point!

Experiment - 10
Hosting a website on Board
Building and hosting a simple website(static/dynamic) on the device and make it
accessible online. There is a need to install server(eg: Apache) and thereby host the
website.
Setting up an Apache Web Server on a Raspberry Pi
Apache is a popular web server application you can install on the Raspberry Pi to allow it to
serve web pages.
On its own, Apache can serve HTML files over HTTP, and with additional modules can
serve dynamic web pages using scripting languages such as PHP.
Install Apache
First, update the available packages by typing the following command into the Terminal:
sudo apt update
Then, install the apache2 package with this command:
sudo apt install apache2 -y
Test the web server
By default, Apache puts a test HTML file in the web folder. This default web page is served
when you browse to http://localhost/ on the Pi itself, or http://192.168.1.10 (whatever the
Pi's IP address is) from another computer on the network. To find the Pi's IP address,
type hostname -I at the command line (or read more about finding your IP address).
Browse to the default web page either on the Pi or from another computer on the network and
you should see the following:

This means you have Apache working!
Changing the default web page
This default web page is just an HTML file on the filesystem. It is located
at /var/www/html/index.html .
Navigate to this directory in a terminal window and have a look at what's inside:
cd /var/www/html
ls -al
This will show you:
total 12
drwxr-xr-x 2 root root 4096 Jan 8 01:29 .
drwxr-xr-x 12 root root 4096 Jan 8 01:28 ..
-rw-r--r-- 1 root root 177 Jan 8 01:29 index.html

This shows that by default there is one file in /var/www/html/ called index.html and it is
owned by the root user (as is the enclosing folder). In order to edit the file, you need to
change its ownership to your own username. Change the owner of the file (the
default pi user is assumed here) using sudo chown pi: index.html .
You can now try editing this file and then refreshing the browser to see the web page change.
Your own website
If you know HTML you can put your own HTML files and other assets in this directory and
serve them as a website on your local network.
Additional - install PHP
To allow your Apache server to process PHP files, you'll need to install the latest version of
PHP and the PHP module for Apache. Type the following command to install these:
sudo apt install php libapache2-mod-php -y
Now remove the index.html file:
sudo rm index.html
and create the file index.php :
sudo nano index.php
Put some PHP content in it:
<?php echo "hello world"; ?>
Now save and refresh your browser. You should see "hello world". This is not dynamic but
still served by PHP. Try something dynamic:
<?php echo date('Y-m-d H:i:s'); ?>

or show your PHP info:
<?php phpinfo(); ?>

Experiment – 11
Webcam Server
Interfacing the regular usb webcam with the device and turn it into fully functional IP
webcam & test the functionality.
Using a standard USB webcam
Rather than using the Raspberry Pi camera module, you can use a standard USB
webcam to take pictures and video on the Raspberry Pi.
Note that the quality and configurability of the camera module is highly superior to
a standard USB webcam.
Install fswebcam
First, install the fswebcam package:
sudo apt install fswebcam
Add your user to video group
If you are not using the default pi user account, you need to add your username to
the video group, otherwise you will see 'permission denied' errors.
sudo usermod -a -G video <username>
To check that the user has been added to the group correctly, use
the groups command.
Basic usage
Enter the command fswebcam followed by a filename and a picture will be
taken using the webcam, and saved to the filename specified:
fswebcam image.jpg
This command will show the following information:

--- Opening /dev/video0...
Trying source module v4l2...
/dev/video0 opened.
No input was specified, using the first.
Adjusting resolution from 384x288 to 352x288.
--- Capturing frame...
Corrupt JPEG data: 2 extraneous bytes before marker 0xd4
Captured frame in 0.00 seconds.
--- Processing captured image...
Writing JPEG image to 'image.jpg'.
Note the small default resolution used, and the presence of a banner showing the
timestamp.
Specify resolution
The webcam used in this example has a resolution of 1280 x 720 so to specify the
resolution I want the image to be taken at, use the -r flag:
fswebcam -r 1280x720 image2.jpg
This command will show the following information:

/dev/video0 opened.
Writing JPEG image to 'image2.jpg'.
Picture now taken at the full resolution of the webcam, with the banner present.
Specify no banner
Now add the --no-banner flag:
fswebcam -r 1280x720 --no-banner image3.jpg
which shows the following information:
/dev/video0 opened.
Disabling banner.
Writing JPEG image to 'image3.jpg'.

Now the picture is taken at full resolution with no banner.
Bad Pictures
You may experience poor quality pictures with a USB webcam, such as this
accidentally artistic piece:
Some webcams are more reliable than others, but this sort of issue may occur with
poor quality webcams. If the problem persists, ensure your system is up to date.
Also try other webcams, but you'll get the best performance from the Raspberry
Pi camera module.

Bash script
You can write a Bash script which takes a picture with the webcam. The script
below saves the images in the /home/pi/webcam directory, so create
the webcam subdirectory first with:
mkdir webcam
To create a script, open up your editor of choice and write the following example
code:
#!/bin/bash
DATE=$(date +"%Y-%m-%d_%H%M")
fswebcam -r 1280x720 --no-banner /home/pi/webcam/$DATE.jpg
This script will take a picture and name the file with a timestamp. Say we saved it
as webcam.sh , we would first make the file executable:
chmod +x webcam.sh
Then run with:
./webcam.sh
Which would run the commands in the file and give the usual output:
/dev/video0 opened.

Disabling banner.
Writing JPEG image to '/home/pi/webcam/2013-06-07_2338.jpg'.
Time-lapse using cron
You can use cron to schedule taking a picture at a given interval, such as every
minute to capture a time-lapse.
First open the cron table for editing:
crontab -e
This will either ask which editor you would like to use, or open in your default editor. Once
you have the file open in an editor, add the following line to schedule taking a picture every
minute (referring to the Bash script from above):
* * * * * /home/pi/webcam.sh 2>&1
Save and exit and you should see the message:
crontab: installing new crontab
Ensure your script does not save each picture taken with the same filename. This
will overwrite the picture each time.

IOT lab ManualArduino_IOTArduino_IOTArdu

Recommended

More Related Content

Similar to IOT lab ManualArduino_IOTArduino_IOTArdu (20)

More from deepikayadav216323 (14)

Recently uploaded (20)

IOT lab ManualArduino_IOTArduino_IOTArdu