Room Temperature and Humidity Monitoring System Based on Internet of Things (IoT) Using ESP32 and DHT22 Sensor

Abstract

Temperature and humidity conditions represent critical environmental parameters that require continuous monitoring, particularly in the context of sensitive device storage and room comfort. Conventional manual monitoring approaches are considered inefficient and prone to human error. This research proposes the design and implementation of a room temperature and humidity monitoring system based on the Internet of Things (IoT) using the ESP32 microcontroller and DHT22 sensor, with the Thinger.io cloud platform serving as a real-time data visualization interface. The methodology encompasses hardware design, firmware development using Arduino IDE, and Thinger.io dashboard configuration through the Stream by Device method. Physical testing demonstrated that the ESP32 Wi-Fi module successfully connected to the local network and the Thinger.io platform with Connected (Online) status, confirming successful implementation of the IoT network layer. However, sensor data acquisition experienced complete failure due to a damaged DHT22 component, as indicated by Not a Number (NaN) output values on the Serial Monitor. Software validation was conducted through the Wokwi circuit emulator, confirming that the program logic and data transmission mechanism functioned correctly. This research concludes that the failure was isolated to the physical component, while the software architecture and IoT integration were fully and successfully implemented.