Building a Web-Based Fire Alarm Using ESP32, Flame and Smoke Sensors, and Arduino Cloud

In this tutorial, we will build a web-based fire alarm system using an ESP32 microcontroller, a flame sensor, a smoke sensor, and Arduino Cloud. This project will provide real-time alerts and allow you to monitor fire-related events remotely via a web interface.

Components Needed

Project Overview

The fire alarm system will:

1. Detect flame using a flame sensor.
2. Detect smoke using a smoke sensor.
3. Trigger a buzzer or LED as a local alert.
4. Send real-time data to the Arduino Cloud for remote monitoring.
5. Display sensor readings on a web dashboard.

Step 1: Setting Up the Hardware

Circuit Diagram

1. Connect the Flame Sensor:

• VCC to 3.3V on the ESP32.
• GND to GND on the ESP32.
• Signal pin to D34 on the ESP32 (or any other GPIO).

2. Connect the Smoke Sensor:

• VCC to 5V on the ESP32.
• GND to GND on the ESP32.
• Analog output pin (AOUT) to A0 (or any analog pin on the ESP32).

3. Connect the Buzzer or LED:

• Positive pin to D27 (or another GPIO).
• Negative pin to GND.

Step 2: Preparing the Arduino Cloud

Create an Arduino Cloud Account

1. Visit Arduino Cloud and create an account if you don’t have one.

Set Up a Thing

1. Go to the IoT Cloud section.
2. Create a new Thing and name it (e.g., “Fire Alarm System”).
3. Add two variables:

• • FlameSensor (Type: Float, Permission: Read & Write).
  • SmokeSensor (Type: Float, Permission: Read & Write).

Configure the Device

1. Select ESP32 as your device and configure it by following the steps in the cloud interface.
2. Install the Arduino Create Agent on your computer if prompted.

Step 3: Writing the Code

Install Required Libraries

Open the Arduino IDE and install the following libraries:

• ArduinoIoTCloud for cloud integration.
• WiFi for connecting to the internet.

Code Implementation

Here’s the code for the project:

#include <ArduinoIoTCloud.h>
#include <WiFi.h>

const char SSID[]     = "your-SSID";       // Replace with your Wi-Fi SSID
const char PASSWORD[] = "your-PASSWORD";   // Replace with your Wi-Fi password

float FlameSensor; // Variable to store flame sensor value
float SmokeSensor; // Variable to store smoke sensor value

int flamePin = 34; // GPIO pin for flame sensor
int smokePin = A0; // Analog pin for smoke sensor
int alertPin = 27; // GPIO pin for buzzer/LED

void setup() {
  Serial.begin(115200);

  // Configure pins
  pinMode(flamePin, INPUT);
  pinMode(smokePin, INPUT);
  pinMode(alertPin, OUTPUT);

  // Connect to Wi-Fi and Arduino Cloud
  WiFi.begin(SSID, PASSWORD);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to Wi-Fi...");
  }
  Serial.println("Connected to Wi-Fi");

  // Initialize Arduino Cloud
  ArduinoCloud.begin(SSID, PASSWORD);
  ArduinoCloud.addProperty(FlameSensor, READWRITE, ON_CHANGE, NULL);
  ArduinoCloud.addProperty(SmokeSensor, READWRITE, ON_CHANGE, NULL);

  Serial.println("Arduino Cloud connected");
}

void loop() {
  // Read sensor values
  FlameSensor = analogRead(flamePin);
  SmokeSensor = analogRead(smokePin);

  // Trigger buzzer/LED if fire or smoke is detected
  if (FlameSensor > 1000 || SmokeSensor > 300) { // Adjust thresholds as needed
    digitalWrite(alertPin, HIGH);
  } else {
    digitalWrite(alertPin, LOW);
  }

  // Update cloud variables
  ArduinoCloud.update();
  delay(1000);
}

Step 4: Create a Web Dashboard

1. In the Arduino Cloud, go to the Dashboards section and create a new dashboard.

2. Add widgets:

3. Link the widgets to the respective variables.

Step 5: Testing the System

1. Upload the code to your ESP32 using the Arduino IDE.

2. Open the Serial Monitor to ensure the ESP32 connects to Wi-Fi and the Arduino Cloud.

3. Introduce a flame or smoke near the sensors and observe:

• • The buzzer/LED activates locally.
  • The sensor readings update in the Arduino Cloud dashboard.

Step 6: Optional Enhancements

• Email or SMS Alerts: Use a third-party service like IFTTT or Twilio to send notifications.
• Mobile App Integration: Access your dashboard via the Arduino IoT Cloud mobile app.
• Battery Backup: Add a rechargeable battery to ensure functionality during power outages.

Conclusion

You have successfully created a web-based fire alarm system using an ESP32, flame and smoke sensors, and Arduino Cloud. This project can be expanded into a comprehensive fire safety system for homes, offices, or industrial setups. Stay safe and keep innovating!