The document summarizes a mini-project on an MQ-2 Gas/Smoke Sensor with Arduino. It introduces the MQ-2 sensor, which can detect smoke and gases and is useful for applications like indoor air quality monitoring and early fire detection. It describes connecting the sensor to an Arduino, how the sensor works by outputting a voltage proportional to gas concentration, and testing the sensor to detect cigarette smoke at different locations. The aim is to design a microcontroller-based smoke alarm to detect smoke and activate an alarm.

1. CAUVERY INSTITUTE OF TECHNOLOGY
MANDYA
Mini-Project
Introductory Presentation on
MQ-2 Gas/Smoke Sensor with Arduino
BY-
Prasad H K : 4CA21EC400
Vydesh Gowda N S : 4CA20EC403
Nikhil N : 4CA20EC008
Department of Electronics And Communication
VISVESVARAYA TECHNOLOGICAL
UNIVERSITY BELAGAVI– 590 018

2. Introduction
Nowadays, sensors play a major role in safety systems. In order to detect
smoke and fire, smoke sensors are used. They provide appropriate action on
time for safety purposes. There are numerous types of sensors available to
measure environmental characteristics like light, noise, smoke, etc.
One such sensor used in safety systems to detect harmful gases is the MQ2
Gas sensor. If you want to make an indoor air quality monitoring system,
breath checker, or early fire detection system, the MQ2 sensor is a suitable
choice.

3. There were many previous studies that discussed smoke detection, there are quite a
number of them, including a cigarette detection system in a closed room based on
the Internet of Things (IoT)(Sulistiyowati et al., 2019). Design of acigarette smoke
detection system using an Arduino-Based Short Message Service (SMS) Alert
(Mandarani et al., 2016) and (Utomo & Saputra, 2016). Design of the Multiple
Warning system for detecting cigarette smoke using an Arduinobased MQ-135
sensor (Gustavia & Nurraharjo, 2018). Sensor, microcontroller, and IoT based smoke
and fire detection system design (Waworundeng, 2020). Design and build a detector
and neutralizer of indoor cigarette smoke using the Arduino-based PI (Propositional
Integral) method (Rahmat et al., 2018). Design and build a smoke and flame detector
for health and fire prevention based on Arduino Uno and GSM Sim900A (Hamdani et
al., 2019)
3
Literature Survey

4. Objective
The primary objective of this project is to design a microcontroller based smoke
alarm to detect the presence of smoke and to activate an alarm. · Analysis and
calibration of Arduino microcontroller. · Analysis and calibration of MQ-2 smoke
sensor. · Analysis and installation of ESP8266 WIFI module. · Installation of LCD
display and LED to develop visual warnings indicating the presence of smoke.
Installation of buzzer to display audio warnings to indicate the presence of smoke.
4

5. Methodology
• Connect the VCC pin of the sensor to the 5V of the Arduino.
• Connect the GND of the sensor to the GND of the Arduino.
• Connect the digital pin of the sensor D0 to the digital pin number 8 of the
Arduino
• Connect the analog pin of the sensor to the analog pin A0 of the Arduino.

6. How does it work?
The voltage that the sensor outputs changes accordingly to the smoke/gas level that
exists in the atmosphere. The sensor outputs a voltage that is proportional to the
concentration of smoke/gas.
In other words, the relationship between voltage and gas concentration is the
following:
•The greater the gas concentration, the greater the output voltage
•The lower the gas concentration, the lower the output voltage
.

7. Pin Wiring
Pin Wiring to Arduino Uno
A0 Analog pins
D0 Digital pins
GND GND
VCC 5V
The MQ-2 sensor has 4 pins:
The output can be an analog signal (A0) that can be read with an analog input of the
Arduino or a digital output (D0) that can be read with a digital input of the Arduino.

8. Parts Required
MQ-2 gas sensor
Arduino UNO R3
Board
Red LED
Bread board
Buzzer
3 x 220Ω
Resistor
Jumper Wires Green LED

9. Schematics

10. Applications
 These sensors are used to detect the presence of gases in the air such as
methane, butane, LPG and smoke but they are unable to distinguish between
gases. Thus, they cannot tell which gas it is.
 This sensor is also used for Air quality monitoring, Gas leak alarm and for
maintaining environmental standards in hospitals.
 In industries, these are used to detect the leakage of harmful gases.
 It can detect gases in the concentration of range 200 to 10000ppm.

11. Result
At the end we can conclude that with the right calibration, the MQ-2 can
be used for detecting (and alarming) larger quantities of combustible
gases in houses or storages. In this paper one possible solution for
realization of detector system for recognizing presence of smoke or
combustible gases is presented.

12. Conclusion
12
The ability of this smoke detector to detect the
presence of cigarette smoke in the air depends on
the concentration of smoke, the distance from the
source and sensor, and the direction of movement of
the smoke.
And from the results of tests carried out at three
locations, it was explained that a closed room
equipped with a colling fan to clean cigarette smoke
levels made the room cleaner and reduced co2
levels.

13. References
13
1] M. Ahrens, “U.S. vehicle fire trends and patterns,” National Fire Protection Assoc., Quincy,
MA, NFPA No. USS27-01, 2010. [2] N. Navet and F. Simonot-Lion, Eds., Automotive
Embedded Systems Handbook (Industrial Information Technology Series). Boca Raton, FL:
CRC, 2008. [3] I. S. Wichman, “Material flammability, combustion, toxicity and fire hazard in
transportation,” Prog. Energy Combustion Sci., vol. 29, no. 3, pp. 247–299, 2003. [4] L.
Halada, P. Weisenpacher, and J. Glasa, “Computer modelling of automobile fires,” in
Advances in Modeling of Fluid Dynamics. London: InTechOpen Publishers, 2012, pp. 203–
228. [5] C. Von Altruck, “Fuzzy logic in automotive engineering,” Circuit Cellar Mag., no. 88,
pp. 1–9, Nov. 1997. [6] Candra, R. A., Suherman, & Ilham, D. N. (2021). Amplitude range
data validation in Internet of Things (IoT) sensor. IOP Conference Series: Earth and
Environmental Science, 644(1). https://doi.org/10.1088/1755-1315/644/1/012063 .

14. Thank You