R.V.

COLLEGE OF ENGINEERING,
BENGALURU-560059
(Autonomous Institution Affiliated to VTU,
Belagavi)

TITLE
EXPERIENTIAL LEARNING REPORT

Submitted by:

NAME OF THE CANDIDATE(S) ROLL NO

1.Rashmitha RVCE22BEI049/40
2.Shreesha K RVCE22BEI060/52
3.Spoorti P. C RVCE22BEI041/55
4.Vinyas K S RVCE22BEI061/62

Faculty In charge
1. Dr. Niranjan P. K. Linear Algebra Calculus & Numerical(22MA11A)

2. Dr. Rajesh B. M Condensed Matter Physics for Engineers

(22PHY12A)

3. Dr. Rachana S. Akki Basic Electronics (22EC13)

Electronics and Instrumentation Engineering

i
Electronics and Instrumentation Engineering
 R.V. COLLEGE OF ENGINEERING, BENGALURU - 560059
(Autonomous Institution Affiliated to VTU, Belgaum)

DEPARTMENT OF ELECTRONICS AND INSTRUMENTATION

CERTIFICATE
It is certified that the Experiential learning titled ‘Simple sensors for environmental application’ is
carried out by Spoorti (RVCE22BEI41), Shreesha(RVCE22BEI060), Vinyas(RVCE22BEI061) and
Rashmitha(RVCE22BEI049), who are bonafide students of R.V College of Engineering, Bengaluru,
during the first semester, in the year 2022-2023. It is also certified that all corrections/suggestions
indicated for the Internal Assessment have been incorporated in the report. The report has been approved
as it satisfies the academic requirements in respect of Experiential learning.
Marks awarded
Signature of Staff In-charge

Signature of Head of the Department

Electronics and Instrumentation Engineering ii

Electronics and Instrumentation Engineering iii
 Table of Contents
Acknowledgement ............................…
iv
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

1. Introduction
1.1 Methodology

2.Literature Survey
2.1 Paper 1 and paper 2(Author, paper title, publications Details, summary,
References)
2.2 Paper 3 and paper 4
2.3 Paper 5
2.4 Paper 6 and Paper 7
3.Concept and Relevance to Seminar components
3.1 About gas sensors
3.2 Components required
4.Implementation
4.1.Program logic
4.2 Simulation circuit
4.3 comparative graph of simulation and real time experiment using Arduino IDE
5.Results
6.1 Discussion
6.2 Inference
6.Conclusion
7.References

Electronics and Instrumentation Engineering iv

 RV COLLEGE OF ENGINEERING®,
BENGALURU-560059

Acknowledgement

We would like to acknowledge the help and support of people without

which this project couldn’t have been, foremost in which is our guide and
head of the department Dr. Rudranna Nandihalli. Also we would like to
mention the principal, RVCE, Dr. K N Subramanya.

Electronics and Instrumentation Engineering iv

Electronics and Instrumentation Engineering iv
 Abstract:
Building Automation is a part of the energy-saving drive. With automation, a
workflow that operates independently or without constant human oversight is
implemented and this removes the human error and dependency.

Sensors are a huge topic to dive into. The recent Technology of robotics relies on
three main components namely: sensors, controller and actuators.

Sensors play the most important role as automatics are all about collecting real data
and making instantaneous decisions. Sensors also play a very important role when it is
chosen for environmental application. In this paper, we will discuss gas sensors.

Electronics and Instrumentation Engineering iv

Electronics and Instrumentation Engineering v
 Chapter 1: Introduction

What is a sensor?
It is a device that collects physical quantities such as temperature,
humidity, etc. and converts it into an output that can be understood
by humans and which can be worked upon.
Sensors play a very important role in our lives. Even the scientists
and engineers are working very hard to find ways to use sensors to
the fullest. We can’t imagine our lives without sensors, we can use
them in everything be it our phones or the lighting of the bathroom.
There are many types of sensors such as thermal, light, sound, etc.
Human olfactory senses cannot detect only 400000 odors .
Nevertheless, it cannot detect the gases that are low in concentration
or the gases that are odorless. Earlier devices like mass
spectrometers, flame ionization detectors and devices were used.
However, it was replaced by technological device-sensors as it is
smaller in size. We use gas sensors to measure pollutants in air.
According to WHO, the pollutants in air is due to harmful gases and
has caused 7 million deaths in 2012. Since burning of fossil fuel,
emission of cars and industrial factories give out CO(carbon
monoxide), it is considered one of the harmful gases in the
atmosphere.

Electronics and Instrumentation Engineering v

Gas Sensors: The device that detects the concentration of gases in
the environment and converts it into electrical signals.
Types of Gas Sensors:
1.Optical Gas Sensors
2.Metal Oxide Gas Sensors
3.Capacitive Gas Sensors
4.Thermal conductivity Gas Sensors and so on…

Electronics and Instrumentation Engineering v

 1.1 Methodology
The methodology adopted in this project is as follows:-

• Study of currently available home automation solutions

• Development of approach for air quality monitoring system
• Design and Simulation of detailed schematics
• Comparison of simulation results and practical results

These are discussed below in detail.

Electronics and Instrumentation Engineering Page 1

Chapter 2: Literature Survey

Research paper review

2.1
Author Paper Title Publication Summary Reference
Details

Abdullah J. Air Quality 2019 i) VOCs are very [1] Fenske, J. D., &
Alabdullah, Badr Arduino Information harmful and their Paulson, S. E. (1999).
I. Farhat, Based Security detection is very Human breath emissions of
Slim Chtourou Monitoring (ICCAIS),Ri important. VOCs. Journal of the Air &
System yadh, Saudi ii)These can cause Waste Management
Arabia many health problems Association, 49(5), 594-
IEEE Xplore such, Nasal tumors, 598.
asthma, etc. [2] Bai, Z., Jia, C., Zhu, T.,
iii)With the help of the & Zhang, J. (2002). Indoor
arduino board and the air quality related standards
sensor a system can be in China. Proceedings of the
made which will notify Indoor Air.
the user about the [3] GREENGUARD
levels of gases. Environmental Institute. A
Study of IAQ in
Automobile Cabin Interiors.
Available on :
www.greenguard.org ,
accessed on 2018/4/17.

Nurul Athirah Air Quality 2022 IEEE i) Measuring the Air [1] V.V. Tran, D. Park and
Mohd Kosim, Monitoring 13th Control quality is very Y. C Lee, "Indoor Air
Siti Lailatul System and System important as it helps Pollution, Related Human
Mohd Hassan, Ili using Graduate people to protect Diseases, and Recent
Shairah Abdul Arduino Research themselves from the ill Trends in the Control and
Halim, Noor and Matlab Colloquium effect of poor quality Improvement of Indoor Air
Ezan Abdullah, Analysis (ICSGRC), air. Quality," International
A’zraa Afhzan 23 July 2022, ii) Car left on for more Journal of Environment
Ab. Rahim Shah Alam, than 10 minutes will Research and Public Health,
Selangor, harm the people by pp. 1-27, 2020.
Malaysia polluting the air in the [2] S. Kumar and A. Jasuja,
garage. "Air Quality Monitoring
iii) Proper ventilation System Based on IoT using
should be made to Raspberry Pi," International
protect oneself from Conference on Computing,
poor quality air. Communication and
Automation, pp. 1341

2.2

Electronics and Instrumentation Engineering Page 1

 Authors Paper Title Publication Summary References
Detail

1.Farah Capable of Internation i. Concentration of Gases [1]http://www.arduino.cc/

Neamah Gas Sensor al Journal like CO, CO2,NH4, [2]http://
2.Mis Intisar MQ-135 to of Acetone, toluene and www.arduino.org/
3.Zainab Monitor the Engineerin Ethanol are calculated by [3] Intisar M. Saadoon ,
Khyioon Air Quality g Research MQ135 sensor. journal of engineering and
4. Elaf Nassir with Arduino and ii. Block Diagram of applied
Abud uno Technology system configuration. science,"Electroencephalo
. ISSN iii. Sensitivity graphy (EEG) for control
0974-3154, Characteristics of MQ135. the luminaire system with
Volume 13, iv. The Result was that: Arduino" , Volume 14
Number 10, I. If MQ135 detects air Issue 20 (2019) Page
IEEE quality between 1000 ppm 7448-7452.
Xplore to 2000 ppm then it’s a [4]
Poor Air. http://www.instructables.c
II. If MQ135 detects air om/.
quality greater than 2000 [5]
ppm, then air contains http://en.wikipedia.org/
pollutants

2.3
Author Paper Title Publication Summary Reference
Details

1)Munmun Ghosal A Quadcopter 2018 Trends i) This project is [1]B. Marinovl) Marin,
Based in Electronics mainly designed to Topalovl) Ivan, Gieva2)
2)Anku Bobade Environment and track the location Elitsa and Nikolov1)
Health Informatics where there is high air Georgi, "Air Quality
3)Preeti Verma Monitoring (ICOEI) pollution. Monitoring in Urban
System for ii) It also used to Environments", IEEE,
Smart Cities measure the air 2016.
parameters such as [2]Movva Pavani and P.
smoke,CO2,the Trinatha Rao, "Real
intensity of Time Pollution
light,temperature,humi Monitoring Using
dity continuously . Wireless sensor
iii) This project is Networks", IEEE,2016.
helpful in the better
production of crop in
farming..

1) Hussein Application of 2021,Intellige 1) MQ- sensor 1) Ahmed, Md

J.Khadim MQ-Sensors to nt connected with Mohiuddin, Suraiya
2) Faik K. Obaed Indoor Air Technology, Arduino and Banu, and Bijan Paul.

Electronics and Instrumentation Engineering Page 1

 3) Ziad T. Abd ali Quality System and concentration of "Real-time air quality
Monitoring in Service for different gas present in monitoring system for
Lab based on Internet of the air is measured. Bangladesh's
IoT Everything 2) When the air quality perspective based on
(ITSS-IoE) concentration is less Internet of Things.".
than 100ppm,it is a
fresh air. 2) Ibrahim, Ahmed
3) If air quality Abdullah. "Carbon
concentration rises to Dioxide and Carbon
Monoxide Level
200ppm(critical case),
Detector." In 2018 21st
it causes migraines in International
humans. Conference of
4)If it crosses 250ppm Computer and
(danger case), that Information Technology
poses serious health (ICCIT), pp. 1-5. IEEE,
2018.
risks to those subjected
to such a poor air

2.4

Electronics and Instrumentation Engineering Page 1

 Author Paper Title Publication Summary References
Detail

1)Shubhajit Design and 2021 i) If we take the CO present in [1]K. Okokpujie, E.

Vishwas Developmen Odisha, the atmosphere it affects our Noma-Osaghae, O.
t of Arduino Electrical heart, brain, and kidney. NOx Modupe, S. John, and O.
2)Sayantan Based Power
affects the lung and causes Oluwatosin, “A Smart Air
Saha, Portable Air Engineering
Quality , respiratory problems. To detect Pollution Monitoring
Monali Nath CO, NOx, and other gases System”, International
Bhowmik Monitoring Communica
Systems tion and present in the air we use Journal of Civil
(UG
Students), Computing sensors. Engineering and
Technology Technology, vol.9, No.9,
3) Amitabha (ODICON) ii) Initially, we interfaced the pp.799-809, Sept. 2018.
Nath MQ-135 sensor with Arduino to
check their response to various [2] H. Gupta, D.
gases present in the air. Obtain Bhardwaj, H. Agrawal, V.
the concentration of different A. Tikkiwal, and A.
gases in different atmospheric Kumar, “An IoT Based
conditions. Air Pollution Monitoring
System for Smart Cities”,
iii) We can analyze and 2019 IEEE International
monitor the obtained data. Then Conference on Sustainable
we can define effective methods Energy Technologies and
for the prevention and control of Systems (ICSETS),
pollution. Bhubaneswar, India.
(2019). pp.173- 177,
doi:10.1109/ICSETS.2019
.8744949

Chapter 3:
Electronics and Instrumentation Engineering Page 1
Concepts and relevance to Seminar component

3.1 Gas sensor (MQ135):

1. MQ-135 sensor is a metal oxide based gas sensor.
2. This can detect gases like Ammonia, Nitrogen oxides, alcohol, benzene, smoke, carbon
dioxide, etc.
3. Dimensions : 35mm x 22mm x 23mm
4. Working voltage : 5V DC
5. Range:10 to 1000 PPM of different gases.
6. This has an exoskeleton under which there is a sensing element. Current is passed
through the sensor with the help of connecting leads.Signals from sensors vary in relation
to ion sorption process. It is well defined by free charge carriers from sensing layer to
adsorbed surface.
7. The general requirements of this sensor in order to implement in specific environmental
applications are sensitivity, selectivity and stability.

3.2 Working of the sensor

1. The 2 systems that affects electron transfer process is
i. the reduction of free electrons at the oxide surface and this alters potential barrier hence
sensing of gas process is dependent on width and height of contact potential barrier.

Electronics and Instrumentation Engineering Page 1

 ii. The determination of fermi level by surfaces under flat energy bands is mainly
dependent on emission of electrons from surface to conduction band.
3. Effectiveness of MQ135 depends on response(R)=(Ra/Rg) or (Rg/Ra)
4. Ra/Rg for n type metal oxides and Rg/Ra for p type.

For slope we choose two points. Say (200,2.6) and (10000,0.75 ) for LPG line or any such line
m = log y - log y0
log x - log x0

m = log(0.75/2.6)
log(10000/200)
m = -0.318

Again to calculate y intercept we need to take another point , say (5000,0.9) of CO2 line

log y = m log x + c

c = log(0.9) - (-0.318 )*log(5000)

c = 1.13

So gas concentration for any ratio is given by

Log x = log y - b/m

x = 10^((log y - b)/m) - 1)
Rs =[(Vc x RL)/VRL] - RL – 2)
Using 1 and 2 sensors are calibrated

3.3 Components Required:

i .Arduino UNO
ii. Breadboard
iii. Jumping wires
iv. MQ135 gas sensors
v. LCD(16x2)
vi. LED

For CO2/Smoke
#include <LiquidCrystal.h>
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
int redLed = 10;
int greenLed = 12;
int buzzer = 8;
int smokeA0 = A0; // Your threshold value
Electronics and Instrumentation Engineering Page 1
int sensorThres = 400;
void setup()
{
pinMode(redLed, OUTPUT);
pinMode(buzzer, OUTPUT);
pinMode(smokeA0, INPUT);
Serial.begin(9600);
lcd.begin(16,2);
}
void loop()
{
int y1 = analogRead(A0);
Serial.println(y1);
int analogSensor = analogRead(smokeA0);
Serial.print("Pin A0: ");
Serial.println(analogSensor);
lcd.print("Smoke Level:");
lcd.print(analogSensor-50); // Checks if it has reached the threshold value
if (analogSensor-50 > sensorThres)
{
digitalWrite(redLed, HIGH);
lcd.setCursor(0, 2);
lcd.print("Alert....!!!");
digitalWrite(12, LOW);
tone(buzzer, 1000, 200);
}
else
{
digitalWrite(redLed, LOW);
digitalWrite(12, HIGH);
lcd.setCursor(0, 2);
lcd.print(".....Normal.....");
noTone(buzzer);
}
delay(500);
lcd.clear();}

Electronics and Instrumentation Engineering Page 1

Electronics and Instrumentation Engineering Page 1
4.2 Air Quality Index
Electronics and Instrumentation Engineering Page 1
#include <LiquidCrystal.h> //Header file for LCD
const int rs=7, en=6, d4=5, d5=4, d6=3, d7=2; //pins of LCD connected to Arduino
LiquidCrystal lcd(rs,en,d4,d5,d6,d7); //lcd function from LiquidCrystal

int buz = 8; //buzzer connected to pin 8

int led = 12; //led connected to pin 9
const int aqsensor = A0; //output of mq135 connected to A0 pin of Arduino
int threshold = 100; //Threshold level for Air Quality
void setup()
{
pinMode (buz,OUTPUT); // buzzer is connected as Output from Arduino
pinMode (led,OUTPUT); // led is connected as output from Arduino
pinMode (aqsensor,INPUT); // MQ135 is connected as INPUT to arduino

Serial.begin (9600); //begin serial communication with baud rate of 9600

lcd.clear(); // clear lcd
lcd.begin (16,2); // consider 16,2 lcd

void loop()
{
int ppm = analogRead(aqsensor); //read MQ135 analog outputs at A0 and store it in ppm
Serial.print("Air Quality: "); //print message in serial monitor
Serial.println(ppm); //print value of ppm in serial monitor
lcd.setCursor(0,0); // set cursor of lcd to 1st row and 1st column
lcd.print("Air Quality: "); // print message on lcd
lcd.print(ppm); // print value of MQ135

if (ppm >threshold) // check is ppm is greater than threshold or not

{
lcd.setCursor(1,1); //jump here if ppm is greater than threshold
lcd.print("AQ Level HIGH");
Serial.println("AQ Level HIGH");
tone(led,1000,200); //blink led with turn on time 1000mS, turn off time 200mS
digitalWrite(buz,HIGH); //Turn ON Buzzer

else
{
Electronics and Instrumentation Engineering Page 1
 digitalWrite(led,LOW); //jump here if ppm is not greater than threshold and turn off LED

digitalWrite(buz,LOW); //Turn off Buzzer

lcd.setCursor(1,1);

lcd.print ("AQ Level Good");

Serial.println("AQ Level Good");

delay (500);

Electronics and Instrumentation Engineering Page 1

 4.3 Alcohol code
#include <LiquidCrystal.h>

Electronics and Instrumentation Engineering Page 1

 LiquidCrystal lcd(7, 6, 5, 4, 3, 2);

int ledPin = 13;

int sensorPin = A0;
int value;

void setup()
{
Serial.begin(9600);
lcd.begin(16,2);
pinMode(ledPin,OUTPUT);
}
void loop()
{
int Value = analogRead(sensorPin);
value = analogRead(A0);
lcd.print("Alcohol Lev.:");
lcd.print(value-50);
Serial.print(value);
if (value-50> 300)
{
digitalWrite(ledPin,HIGH);
lcd.setCursor(0, 2);
lcd.print("Alert....!!!");
Serial.print ("Alert");
}
else {
digitalWrite(ledPin,LOW);
lcd.setCursor(0, 2);
lcd.print(".....Normal.....");
Serial.print("Normal");
}
delay(500);
lcd.clear();
}

Electronics and Instrumentation Engineering Page 1

Electronics and Instrumentation Engineering Page 1
Electronics and Instrumentation Engineering Page 1
 Acetone CH3COCH3
#include <LiquidCrystal.h>
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
int ledPin = 12;
int buzzerPin=8;
int sensorPin = A0;
int value;
void setup()
{
Serial.begin(9600);
lcd.begin(16,2);
pinMode(ledPin,OUTPUT);
}
void loop()
{
int y1 = analogRead(A0);
Serial.println(y1);
int Value = analogRead(sensorPin);
value = analogRead(A0);
lcd.print("Acetone Lev.:");
lcd.print(value);
Serial.print(value);

if (value > 100)

{
digitalWrite(ledPin,HIGH);
digitalWrite(buzzerPin,HIGH);
lcd.setCursor(0, 2);
lcd.print("Alert....!!!");
Serial.print ("\nAlert\n");
}
else
{
digitalWrite(ledPin,LOW);
digitalWrite(buzzerPin,LOW);
lcd.setCursor(0, 2);
lcd.print(".....Normal.....");
Serial.print("\nNormal\n");
Electronics and Instrumentation Engineering Page 1
 }
lay(500):
lcd.clear();
}

Electronics and Instrumentation Engineering Page 1

Electronics and Instrumentation Engineering Page 1
 5. Results:
5.1 Discussion:
Air Pollution is increasing heavily these days due to the many important factors like Vehicle
Emissions, Deforestation, Industrialization [21]. Old vehicles could produce more smoke and hence
those vehicles could be banned from using. But we need a proper metric that tells us what the
intensity level of air pollution is, whether it is low, medium or high. So, we can take help from
various sensors that could detect the air quality and from the corresponding values, we do
mathematical calculations and from that results, we could fix the threshold value from which we
can say whether the desired air quality is below the threshold value or not.
We can use one more sensor that tells the ozone layer status, but it costs very high. Also we can use
PM2.5 laser dust sensors helpful exclusively for vehicle and factory emissions sensing.

5.2 Inference:
After connected the hardware parts of our project and testing the software we got monitoring of
air pollution.

6.Conclusion:
From all the above derivations, connections diagrams, we are able to calculate AirQuality in PPM.
The problem with MQ135 sensor is that specifically it cannot tell the Carbon Monoxide or Carbon
Dioxide level in the atmosphere, but the pros of MQ135 is that it is able to detect smoke, CO,

Electronics and Instrumentation Engineering Page 1

 CO2, NH4.This project can be used both for indoor as well as outdoor. For indoor use, we can
make this kit as a compact device such that if every home started using the device, we can monitor
the indoor air quality of a particular targeted area. Due to increasing air pollution, there is a
necessity to keep an eye on Indoor air quality too. But for outdoor purposes, certainly one sensor is
not sufficient because one sensor has a sensitivity range of around 1 meter, so a network of sensors
has to be deployed to monitor the outdoor air quality. Enough care is taken while calibrating the
sensors.

Electronics and Instrumentation Engineering Page 1

Electronics and Instrumentation Engineering Page 1
Electronics and Instrumentation Engineering Page 1
Electronics and Instrumentation Engineering Page 1
Electronics and Instrumentation Engineering Page 1