International Research Journal of Education and Technology

Environmental degradation as a result of pollution, climate change, and industrial emissions poses major threats to public health and ecosystems. Conventional environmental monitoring systems tend to be non-real-time responsive, based on costly infrastructure, and dependent on manual intervention, hence restricting their applicability in dynamic situations. To overcome these difficulties, we introduce an IoT-based Unpredictable Environmental Monitoring and Alert System using NodeMCU (ESP8266) to track essential parameters like temperature, humidity, and air quality (CO₂, NH₃, benzene, and other toxic gases) in real time.

Our system uses low-cost sensors (DHT11 for temperature and humidity, and MQ135 for air quality) along with a NodeMCU microcontroller, which has been programmed using Embedded C to efficiently monitor and process data. The gathered environmental information is sent over Wi-Fi to a proprietary cloud-based web application, built with PHP and MySQL, for secure and scalable data storage. The system includes a real-time dashboard that displays sensor readings, historical trends, and automated threshold-based alerts. When pollution levels or temperature levels reaches the threshold limits, the system sends alarms through a buzzer and SMS notifications to the authorities to take action.

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Keywords: IoT, Environmental Monitoring, NodeMCU, Real-Time Alerts, Air Quality, DHT11, MQ135, PHP/MySQL