DIY - Auto Smoke Exhaust Fan Kit - D1 Mini, MQ-2, Relay

Overview

This DIY project builds an automatic smoke and gas exhaust fan. A Wemos D1 Mini reads an MQ-2 gas sensor and switches a fan on through a relay when smoke is detected, while showing live readings on an OLED and a web monitor.

How It Works

1. The MQ-2 sensor continuously measures smoke and gas levels in the air.
2. The D1 Mini compares the reading with a threshold and shows it on the OLED and on a live web page.
3. When the level crosses the threshold, the D1 Mini triggers the relay, which switches the DC motor fan on until the air clears.

Complete Parts List

Applications

• Kitchen safety - automatically clears smoke and cooking fumes
• Workshop ventilation - keeps soldering or chemical fumes in check
• IoT monitoring - monitor air quality remotely over WiFi

Full Build Guide

Step-by-step instructions and code for this exact project are on Project Hub.

FAQ

Do I need coding experience? No prior experience is required - this kit is built around one specific project, and the full code is freely available. See the build guide above.

What tools do I need beyond what's included? A computer with the free Arduino IDE (or ESP8266 board support, where applicable) installed to upload the code. No soldering is required for this build.

Can I reuse the parts afterward? Yes - every component in this kit is a standard, reusable part you can use in future projects, not a single-use kit.