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ESP32 smoke detector

Author: Paraschiv Theodor-Vlad
Email: theodor.paraschiv@stud.acs.pub.ro
Master: SRIC

Introduction

This project implements a simple, low-cost smoke and gas detection system using an ESP32 microcontroller, an MQ-2 gas sensor, and an active buzzer. The system reads analog gas/smoke concentration values via the MQ-2 sensor and sends this data periodically to a Firebase Realtime Database.

When dangerous gas levels are detected (above a configurable threshold — 300 in this project), the system triggers an audible alarm using a connected buzzer and sends an immediate alert email via IFTTT Webhooks integration.

A web-based frontend fetches data from Firebase and visualizes it using a graph, with gas/smoke values on the Y-axis and timestamps (converted from UNIX time) on the X-axis, displayed at regular 3-minute intervals.

Hardware Implementation

🧩 Components

ESP32 development board
MQ-2 Smoke/Combustible Gas sensor
Active buzzer
Jumpers / wires

Software Implementation

🖥️ Frontend

TypeScript – The frontend is a TypeScript-based single-page web application designed to visualize real-time gas and smoke concentration data retrieved from a Firebase Realtime Database

☁️ Backend

Firebase – serving as a cloud-hosted NoSQL data store for logging gas/smoke sensor values from the ESP32 microcontroller, data being structured by timestamp-based paths — e.g. /logs/1716760000/value — ensuring clean chronological ordering and ease of querying for frontend consumption
IFTTT - acting as an automation service, receiving webhook triggers from the ESP32 whenever gas/smoke levels exceed a defined threshold, instantly dispatching email alerts to notify the user in real time

📟 Embedded Software (ESP32)

Developed using the Arduino Framework, with the following libraries: