Arduino Fire Alarm

If the flame sensor detects a flame, a buzzer and a LED (connected by a relay) will activate.

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Things used in this project

Hardware components

Adafruit Flame sensor module

Buzzer

LED (generic)

Relay (generic)

Arduino Leonardo

Resistor 221 ohm

Breadboard (generic)

Software apps and online services

Arduino IDE

Story

We did this project as a school homework, then we decided to upload it here to share it with other students, just like us.

The project is a fire alarm piloted by a simple Arduino Leonardo that activates a LED (connected by a relay) and a buzzer, whenever a flame is detected by the flame sensor module.

We hope you will enjoy our little project.

Code

Fire alarm with Arduino Leonardo

int relay = 4 ;// define relay pin
int flamedigital = 9; // define the flame sensor digital pin
int flameanalog = A3; // define the flame sensor analog pin
int buzzer = 11; //define buzzer pin
int val ; // define numeric variable val
float sensor; //define floating variable sensor

void setup ()
{
  pinMode (flamedigital, INPUT) ;// input interface defines the flame sensor
  pinMode (flameanalog, INPUT) ;// input interface defines the flame sensor
  pinMode (relay, OUTPUT); //output interface defines the relay
  pinMode (buzzer, OUTPUT); //output interface defines the buzzer
}

void loop ()
{
  sensor = analogRead(flameanalog); //read flameanalog value and assigne it to sensor variable


  val = digitalRead (flamedigital) ;// read flamedigital value and assigne it to val variable
  if (val == HIGH) // When the flame sensor detects a signal relay is on and buzzer sound (void alarm)
  {
    alarm();
    digitalWrite (relay, HIGH); //close the relay circuit

  }
  else
  {
    digitalWrite (relay, LOW); //open the relay circuit
  }
  delay(1000);
}

void alarm()  {
  tone(buzzer, 400, 500); //the buzzer emit sound at 400 MHz for 500 millis
  delay(500); //wait 500 millis
  tone(buzzer, 650, 500); //the buzzer emit sound at 650 MHz for 500 millis
  delay(500); //wait 500 millis
}