Design of an IOT based Smart Microclimate Monitoring and Controlling System for Naturally Ventilated Polyhouse Cultivation
Siddharam *
Department of Soil and Water Conservation Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, India.
A. Jinu
Department of Soil and Water Conservation Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, India.
Kari Venkata Sai
Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, India.
V. Harikrishnasagar
Department of Basic Engineering and Applied Sciences, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, India.
V. M. Abdul Hakkim
Department of Soil and Water Conservation Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, India.
K. K. Sathian
Department of Soil and Water Conservation Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, India.
K. P. Rema
Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, India.
Anu Varughese
Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, India.
K. Prasanth
Department of Horticulture, College of Agriculture, Thrissur, India.
*Author to whom correspondence should be addressed.
Abstract
This research addresses the escalating global food demand by developing an automated, IoT-based microclimate monitoring and control system for sustainable greenhouse cultivation. Traditional agricultural practices often suffer from resource inefficiency and high manual labour intensity, which this study mitigates through a precision agriculture framework implemented within a 292 m² naturally ventilated polyhouse at Precision Farming Development Centre, Tavanur. The system architecture integrates a dual-core ESP32 microcontroller as the primary edge processor, utilizing a DHT22 sensor for high-precision temperature and humidity tracking and a BH1750 sensor for ambient light intensity. Data is synchronized via a 4G LTE gateway to the ThingSpeak IoT platform, providing real-time visualization and remote telemetry. Sensor validation demonstrated high fidelity, with R2 values ranging from 0.965 to 0.985 and a rapid 2-second response time. Environmental results revealed a rhythmic diurnal oscillation where air temperature ascended from a nocturnal minimum of 21°C to a stabilized midday peak of 32.5°C. This thermal profile was inversely correlated with relative humidity, which reached a zenith of 85.5% before dropping to 79% under maximum solar gain. Light intensity served as the primary thermodynamic driver, peaking at 70,000 lux in September. The automated system effectively managed these fluctuations through closed-loop control of actuators, including exhaust fans, supplemental lighting, and solenoid valves for irrigation. This integrated approach provides a scalable, economically viable solution for optimizing greenhouse microclimates and enhancing the productivity of sensitive crops like cucumbers.
Keywords: Internet of Things (IoT), precision agriculture, greenhouse microclimate control, ESP32 microcontroller & automation