Ukrainian Journal of Physical Optics


2026 Volume 27, Issue 2


ISSN 1816-2002 (Online), ISSN 1609-1833 (Print)

DEVELOPMENT AND EXPERIMENTAL CHARACTERIZATION OF AN IOT-CONTROLLED RGB LED LIGHTING SYSTEM FOR HYDROPONIC APPLICATIONS

Worsoongnern, S., Yindeesuk, W., Kamoldilok, S., Srinuanjan, K. and Limsuwan, P.

Author Information
Worsoongnern, S., Yindeesuk, W. SCOPUS logo, Kamoldilok, S. SCOPUS logo, *Srinuanjan, K. SCOPUS logo, Limsuwan, P. ORCID logo SCOPUS logo
Department of Physics, School of Science, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand
*Corresponding author: keerayoot.sr@kmitl.ac.th

ABSTRACT

This study presents the development of an Internet of Things-based RGB LED lighting system for precise, flexible light control in hydroponic plants. The system consists of 480 high-power RGB LEDs controlled by an ESP8266 microcontroller, enabling real-time adjustment of light intensity, photoperiod, and color ratios via a smartphone. Pulse-width modulation duty-cycle modulation enables the generation of white light suitable for different stages of plant growth. Experimental results show a linear correlation between illuminance and duty cycle for all color channels. Spectral analysis confirms stable emission within the photosynthetically active radiation range (400–700 nm), with the spectral composition remaining unchanged even when brightness is reduced (dimming). The system demonstrates high control accuracy and adaptability for regulating plant growth lighting, particularly for leafy vegetables such as lettuce.

Keywords: RGB LED lighting, hydroponic plants, spectral analysis, pulse-width modulation, Internet of Things-based control

UDC: 532.2

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    У цьому дослідженні представлено розробку системи світлодіодного освітлення RGB на основі Інтернету речей для точного та гнучкого керування світлом гідропонних рослин. Система складається з 480 потужних RGB-світлодіодів, керованих мікроконтролером ESP8266, що дозволяє регулювати інтенсивність світла, фотоперіод та співвідношення кольорів у режимі реального часу за допомогою смартфона. Широтно-імпульсна модуляція дозволяє генерувати біле світло, придатне для різних стадій росту рослин. Експериментальні результати показують лінійну кореляцію між освітленістю та прогальністю для всіх колірних каналів. Спектральний аналіз підтверджує стабільне випромінювання в діапазоні фотосинтетично активного випромінювання (400–700 нм), при цьому спектральний склад залишається незмінним навіть при зменшенні яскравості (затемненні). Система демонструє високу точність керування та адаптивність для регулювання освітлення росту рослин, особливо для листових овочів, таких як салат.

    Ключові слова: світлодіодне освітлення RGB, гідропонні рослини, спектральний аналіз, широтно-імпульсна модуляція, керування на основі Інтернету речей

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