How to Make Flame Alarm with Arduino?

1.Introduction
 

In this project, we will use the Plus mainboard, a flame sensor and a buzzer to make a fire alarm device.
 

2.Components Required
 

3.Component Knowledge
 

Flame Sensor

The flame emits a certain degree of IR light, which is invisible to the human eye, but our flame sensor can detect it and alert the microcontroller. If the Arduino has detected a fire, it has a specially designed infrared receiver to detect the flame, and then convert the flame brightness into a fluctuating level signal. The short pin of the receiving triode is negative pole and the other long pin is positive pole. We should connect the short pin (negative pole) to 5V and the long pin (positive pole) to the analog pin, a resistor and GND. As shown in the figure below.

Note: Since vulnerable to radio frequency radiation and temperature changes, the flame sensor should be kept away from heat sources like radiators, heaters and air conditioners, as well as direct irradiation of sunlight, headlights and incandescent light.
 

4.Read the Simulation Value
 

We start with a simple code to read the value of the flame sensor and print it on the serial monitor. For wiring, please refer to the following wiring diagram.

/*
Read_the_flame_sensor_analog_value
http//www.keyestudio.com
*/
int flamepin=A1;// initializes analog PIN A1
int val=0;// defines "val" with an initial value of 0
void setup()
{
Serial.begin(9600);// sets baudrate to 9600
}
void loop()
{
val=analogRead(flamepin);// reads the analog value of analog PIN A1 and assigns it to "val"
Serial.println(val);// displays the value of "val"
}

Upload the code to the Plus Mainboard, connect the wires and power on first. Turn on the serial monitor and set the baud rate to 9600, and approach the flame sensor with a lighter flame to see its analog value.

5.Circuit Diagram and Wiring Diagram
 

Next, we will use flame sensor and buzzer, RGB LED to make an interesting project, that is flame alarm. When flame is detected, RGB LED is red and buzzer alarms.

6.Code
 

/*
Fire_alarm
http//www.keyestudio.com
*/
const int red = 11;
const int green = 10;
const int blue= 9;
const int buzzer = 12;
const int flamepin = A1;
const int thereshold = 30;
void setup() {
  // puts the setup code here and runs it once
  Serial.begin(9600);
  pinMode(red, OUTPUT);
  pinMode(green, OUTPUT);
  pinMode(blue, OUTPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(flamepin, INPUT);
 
}
void setColor(int redValue, int greenValue, int blueValue)
 {
analogWrite(red, redValue);
analogWrite(blue, blueValue);
analogWrite(green, greenValue);
}
 
void loop() {
  // puts the main code here and repeats
  int flamesenseval = analogRead(flamepin);
  Serial.println(flamesenseval);
  if (flamesenseval >= thereshold) {
    setColor(255, 0, 0); //red
    tone(buzzer, 1000);
    delay(10);
  }
  else
  {
    setColor(0, 255, 0); // green
    noTone(buzzer);
  }
}

7.Result

Upload the code to the Plus Mainboard, connect the wires and power on first. Then open the serial monitor and set the baud rate to 9600, the monitor will display the value of the flame sensor. We use light the fire and keep it close to the flame sensor, the RGB LED will become red and the buzzer will alarm. Otherwise, the RGB LED will turn green and the buzzer doesn’t emit sounds.