This project report describes a smoke detection system that uses an Arduino Uno, gas sensor, temperature sensor, servo motor, buzzer, and LED. It takes input from the gas and temperature sensors, and if the gas/temperature rises above a threshold, it sounds the buzzer and activates the servo motor. The servo motor is intended to turn on a water pump to help control a fire. The system provides smoke and fire detection to improve safety in homes, factories, and other buildings.

1. Department of EEE
PROJECT REPORT
Project name : Smoke Detection System
Course no. : EEE 2211
Course name : Measurement and Instrumentation
Submitted by :
14.02.05.134 - A.O.M. Shamsuddoha
14.02.05.136 - Shadab Sadman
14.02.05.157 - Muid Hasan Anik
14.01.05.131 – Mustafizur Rahman

2. SMOKE
DETECTION
SYSTEM
ABSTRACT
A Smoke Detector is a fire protection device
that automatically detects smoke/gases and
also gives us warning to be aware of it, with
some protection system to handle the situation.
Many fire accident occurs in our surrounding
due to absence of human in the right place at
the right time. That is the importance of the
project, it can minimize such accidents. Thus it
got immense importance in our practical life.

3. Equipment used:
1. Arduino uno
2. Gas sensor : MQ-2
3. Temperature sensor : LM-35
4. Servo Motor
5. Buzzer Alarm
6. LED
7. 9V DC Battery
8. 7805 IC
9. Gas lighter (for testing purpose)
Some Instrument Details: (in short)
1. MQ-2 Gas Sensor :

4. Among various types of MQ series gas sensors weselected MQ-2 for their wide
detecting scope, fast response and High sensitivity. They are suitable for
detecting LPG( Liquified Petroleum Gas), i-butane, propane, methane ,alcohol,
Hydrogen, smoke. The gas sensor is mainly composed of tin dioxide on a
ceramic base. The resistance of the sensor varies depending on the
concentration of the reducing gases on the air. We used the module here,
wheresensor’s6pinsareconnected as need internally with resistance.Fourpins
are outside there, VCC (with 5V dc), GND (with Arduino gnd), A0 (from where
we took output, connected it to arduino A0) and D0 (we didn’t use). The power
led(red) turns on when it powered, and the Dout led (green) turns on when it
detects gas.
2. LM-35 temperaturesensor:
The LM35 series are precision integrated-circuit temperature sensors, whose
output voltage is linearly proportionalto the Celsius (Centigrade) temperature.
The LM35 does not require any external calibration or trimming to provide

5. typical accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to
+150°C temperature range.
Other Features :
I. Calibrated directly in ° Celsius (Centigrade)
II. 0.5°C accuracy guaranteeable (at +25°C)
III. Suitable for remote applications
IV. Less than 60 μA currentdrain
V. Low self-heating, 0.08°C in still air
3. 7805 IC
We needed this componenthere to provideextra 5V dc voltage. Because
when we connected two sensors in parallel, current is also distributed in
two parallel paths. As a result LM-35 sensor receives negligible
current(becauseof POTon the MQ-2 it draws mostthe current) and it
doesn’twork properly. For this we need to use7805 IC to providethe
shortageof currentthrough LM-35 as required. Here capacitors arefor
reducing ripple voltage, though it’s not mandatory to use(wehave skipped
this without any trouble). An extra 9V battery is needed to operate the IC.
4. ServoMotor :

6. A servomotor is a rotary actuator or linear actuator that allows for precise
control of angular or linear position, velocity and acceleration. Itconsists of
a suitable motor coupled to a sensor for position feedback. In our project
use of servo motor is quite limited in fact it is optional, we need this for
protection purposeto on and off the water pump switch.

7. Circuit Diagram:

8. Image view :

9. Working Principle :

10. We have used two different sensors : gas sensor and temperature sensor. The
MQ-2 gas sensor senses smoke(dueto fire) and gas leakage ( like methane,
LPG etc. in our kitchen or factory). And the LM-35 temperature sensor is for
detecting temperature rise due to fire. At firstour Arduino UNO will get
information from the two sensors, and then it will comparethe values
according to the condition given in the code. If the values are under the
tolerance level everything will be normal. But if either the temperature or the
concentration of gas rises abovethe condition then the buzzer will be alarmed.
Also if temperature or gas increases further it will operate a servo motor
whosework will be to ON the switch of a water pump to control the fire by
spreading water over the place(we could not arrangethe water system part in
our project). We programmed this device that is implemented on the Arduino-
Uno (ATmega328p) and the value of the concentration of the smokeis given
high so that normalsmoking gas will not be the reason of the device alarm.
This device is designed such as only real fire occurrencewill be the reason for
this device alarming. After the device alarms, the servo motor shaftwill
automatically rotate half of a cycle or 180 degree to switch on the water pump
or water spray. Thus this device can eradicate fire. Gradually when the
condition is under control or back to normal again the servo will switch OFF the
pump and also the buzzer willbe stopped.

11. Code :
#include <Servo.h>
Servo myservo;
int buzz = 10;
int gas = 0;
int smoke= A0;
int temp = 0;
int lm35 = A1;
void setup()
{
myservo.attach(3);
pinMode(buzz,OUTPUT);
pinMode(smoke,INPUT);
pinMode(lm35,INPUT);
Serial.begin(9600);
}
Microcontroller
(Arduino UNO)
Get info./values
fromgas sensor
Get info./values
fromtemp.
sensor
Compere values
according to
condition/Code
Operatethe
buzzer and
servo

12. void loop()
{
temp = analogRead(lm35);
int celsius = temp/2 - 5;
Serial.println(celsius);
gas = analogRead(smoke);
Serial.println(gas);
if(celsius>40 || gas>190)
{
if(celsius>45 || gas>250)
{
digitalWrite(buzz,HIGH);
delay(200);
digitalWrite(buzz,LOW);
delay(200);
int pos = 180;
myservo.write(pos);
delay(5);
}
else
{
int pos = 0;
myservo.write(pos);
delay(5);
digitalWrite(buzz,HIGH);
delay(800);
digitalWrite(buzz,LOW);
delay(800);
}
}

13. else
{
digitalWrite(buzz,LOW);
delay(1000);
}
}
Troubleshooting :
1. When we connect both the sensors with Arduino 5V and GND in parallel,
our LM-35 was not responding as it was responding individually(correctly)
without the MQ-2 gas sensor, dueto currentshortagein it’s branch. For
solving the problemwe used 7805 regulator IC.
2. In different environmentwe need to calibrate the MQ-2 gas sensor
separately either by adjusting the value of it’s POT or change the rangeof
it’s value to operate in the CODE. This is becauseconcentration of gases it
sense, are not same in every place or environment; so it gives values of
different ranges in different places.
3. We also faces difficulties calibrating the LM-35 to show it’s reading in
Celsius scale.
Application:
1. This projectcan be used commercially as a security purposedevice that will
detect fire and gas leakage in our kitchen or factory, mall, museum, hotels,
restaurants, laboratory etc.
2. In many home in our city there occur accident due to gas leakage in the
kitchen, this projectcan be used to minimize this occurrence.
3. On Every Garments Factory, there is a chance of accident for the occurrence
of fire. That is why this device is necessary to use.

14. Discussion:
Though smokedetection system is quite a simple projectbut it has immense
importance and necessity in our practical life. We programmed this device that
is implemented on the Arduino-Uno (ATmega328p) and the value of the
concentration of the smokeis given high so that normalsmoking gas will not
be the reason of the device alarm. We can also add somefurther
improvement in this project. We are planning to use the dc water pump
without servo directly with the Arduino for more reliable and fastresponse.
And also we want to add a GSM module here for sending sms to the owner
when smoke is detected. Itwill be beneficial when no one at home or at a
vacant place.