This is a safety device which is used in labs and in kitchen.This is an Arduino project which can save many lives. It has a gas sensor which can detect any smoke or gas leaks. An alcohol sensor which can detect the presence of any alcohol. It has a temperature sensor to detect high temperatures and a fire alarm to detect fire. I will be showing you a detailed tutorial on how to make it.

Step 1: Watch the Video

Watch this video for more information on this project

Step 2: Materials Required :

1.Arduino Nano - 1

2.Jumper wires set - 1

3.Gas sensor MQ2 - 1

4.Alcohol sensor MQ3 - 1

5.LM35 Temperature sensor - 1

6.Breadboard - 1

7.Red LEDs with resistors pack - 1

8.Buzzer - 1

9.9 volts battery with connector - 2

10.Tube light starter - 1

11.Small buzzer - 1

Step 3: Connecting the Outputs to the Arduino

Buzzer :-

Connect the buzzer to the D12 pin of the Arduino Nano. This will be the Siren of our Project.

LED 1 ( LED for the Gas sensor) :-

Connect this red LED to the D6 pin of the Arduino Nano. This will help us to identify that the gas sensor is be alerted.

LED 2 (LED for the alcohol sensor) :-

Connect this red LED to the D9 pin of the Arduino Nano. This will help us to identify that the alcohol sensor is be alerted.

LED 3 (LED for the temperature sensor) :-
Connect this red LED to the D4 pin of the Arduino Nano. This will help us to identify that the temperature sensor is be alerted.

Step 4: Connecting the Gas Sensor MQ2 to the Arduino Nano

Connect the VCC or 5V pin of the sensor to the 5V pin of the Arduino Nano. This will give us power to the sensor.

Connect the GND pin of the sensor to the GND pin of the Arduino Nano.

Connect the AO pin of the sensor to the A0 pin of the Arduino Nano.

If you have any problems later controlling the sensor connect the DO pin of the sensor to any of the Digital pin.

Step 5: Connecting the Alcohol Sensor MQ3 to the Arduino Nano

Connect the VCC or 5V pin of the sensor to the 5V pin of the Arduino Nano. This will give us power to the sensor.

Connect the GND pin of the sensor to the GND pin of the Arduino Nano.

Connect the AO pin of the sensor to the A1 pin of the Arduino Nano.

If you have any problems later controlling the sensor connect the DO pin of the sensor to any of the Digital pin.

Step 6: Connecting the LM35 Temperature Sensor to the Arduino Nano

Connect the VCC or 5V pin of the sensor to the 5V pin of the Arduino Nano. This will give us power to the sensor.

Connect the GND pin of the sensor to the GND pin of the Arduino Nano.

Connect the AO pin of the sensor to the A2 pin of the Arduino Nano.

If you have any problems later controlling the sensor connect the DO pin of the sensor to any of the Digital pin.

Step 7: Uploading the Code

Copy this code to your Arduino IDE , but you need to change the threshhold value according to the sensitivity of your sensor :-

int gaspin = A0;
int alpin = A1; int tempPin = A2; int gasread; int alread; int tempread; int temp; int gasLED = 6; int alLED = 9; int tempLED = 4; int buzzPin = 12;

void setup() {

pinMode(gasLED,OUTPUT);

pinMode(alLED,OUTPUT);

pinMode(tempLED,OUTPUT);

pinMode(buzzPin,OUTPUT);

Serial.begin(9600);

}

void loop() {

gasread = analogRead(gaspin);

alread = analogRead(alpin);

tempread = analogRead(tempPin);

temp = tempread * 0.48828125;

delay (250);

Serial.print(gasread);

Serial.println(" GAS");

Serial.print(alread);

Serial.println(" AL");

Serial.print(temp);

Serial.println(" .C");

if(temp>55){ \\ change the threshold value accordingly

digitalWrite(tempLED,HIGH);

digitalWrite(buzzPin,HIGH);}

else{

digitalWrite(tempLED,LOW);

digitalWrite(buzzPin,LOW);

}

if (gasread>320){ \\ change the threshold value accordingly

digitalWrite(gasLED,HIGH);

digitalWrite(buzzPin,HIGH);

}

else{

digitalWrite(gasLED,LOW);

digitalWrite(buzzPin,LOW);

}

if (alread>1000){\\ change the threshold value accordingly

digitalWrite(alLED,HIGH);

digitalWrite(buzzPin,HIGH);

}

else{

digitalWrite(alLED,LOW);

digitalWrite(buzzPin,LOW); } }

Step 8: Making the Fire Alarm

Take a tube light starter apart. You will find a capacitor and a chamber. We only need the chamber so remove the capacitor. The chamber will now act as a switch to detect fire. You will observe that it has to untouched points , but when fire is applied to it , the points will come in contact and will trigger the circuit. Build the circuit above in the image consisting of a buzzer,9volts battery and the fire detector.

Step 9: Combine Both of Them

Attach both of the projects most notably on a clear plastic box so you can debug any of the errors and connect a 9volts battery to the GND - Negative and VIN - Positive Terminals of the battery.