IoT-Based Real-Time Smoke and Gas Leak Detection System Using ESP8266 And MQ2 Sensor

These days, it is crucial to protect yourself against indoor hazards like smoke and dangerous gasses, particularly in small, enclosed spaces like homes or even workplaces. This study demonstrates how a basic system was developed to monitor for gas and smoke in real time. Most people don’t consider it, but one malfunctioning appliance or undetected leak can already put everyone at risk. Thus, it monitors the air quality using an ESP8266 NodeMCU and a MQ2 sensor. In order to identify any hazard, the system compares the analog values sent by the sensor to predetermined limits, which are 450 for smoke and 300 for gas. When gas or smoke levels exceed the defined thresholds, the system triggers a buzzer for local alerts and simultaneously sends notifications to a mobile device through the Blynk mobile application. Real-time sensor data and system status are displayed in the Blynk mobile app, and a virtual reset button is included to allow users to clear alerts and deactivate the buzzer remotely. The firmware uses conditional flags to prevent repeated alerts for the same hazard event, ensuring efficient performance and avoiding notification spamming. This implementation demonstrates the integration of low-cost, off-the-shelf components with cloud-based mobile platforms to provide a reliable and responsive safety system. System testing shows that the device can effectively detect changes in gas and smoke concentration, respond within one second, and update the user interface accordingly. In conclusion, the proposed system meets its objectives by delivering a functional, cost-effective, and user-friendly air monitoring device that enhances safety through early warning alerts and real-time control, making it suitable for residential and small-scale applications.