IoT-Based Soil Moisture Monitoring and Drip Irrigation System for Chili Plants Using NodeMCU and Blynk

Abstract

Water management is one of the most important factors influencing the growth and productivity of chili plants. Conventional irrigation methods often result in inefficient water consumption because watering is performed manually without considering actual soil moisture conditions. This study aims to develop an Internet of Things (IoT)-based drip irrigation system capable of monitoring soil moisture in real time using NodeMCU ESP8266 and the Blynk application. The proposed system integrates four YL-69 soil moisture sensors, a DHT22 temperature sensor, an I2C LCD, a relay module, and a DC water pump. Median Filtering is implemented to reduce fluctuations in soil moisture measurements before controlling the irrigation process. The system automatically activates the water pump when soil moisture is below 60% and stops irrigation when soil moisture exceeds 80%. Experimental results demonstrate that the developed system successfully performs automatic irrigation, provides real-time monitoring through both the I2C LCD and Blynk platform, and improves the stability of sensor readings using Median Filtering. Therefore, the proposed system can support efficient water management and smart agriculture applications for chili cultivation.