Design and Development of a Tunable LED lamp for Horticultural Lighting

This paper presents a prototype of tunable LED lamp for horticultural lighting, consisting of four LED types at blue (451 nm), red (660 nm), far-red (730 nm) and 4000 K cool white. The lighting system also has separate UV (360-370 nm) LED tubes. Light intensity is regulated through a 0-10 V control signal, generated from a Pulse Width Modulation (PWM) signal by the ESP32 and a PWM-to-voltage converter and controlled by adjusting control signals using genetic algorithm. The average value of produced photosynthetic photon flux density (PPFD) is about 1,134.13 µmol m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> at 30 cm with a standard deviation of 82.69 µmol m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup>. The algorithm is well performed with an average total error of 0.17% from test cases.