Abstract :
The narrowing of agricultural land changes the function of the planting medium from the soil medium to the water medium. This farming technique is called hydroponics. The process that really determines the results of hydroponic planting is the stage of sowing the seeds. At this stage, plant seeds require special handling, one of the factors that greatly influences plant growth is light, which is needed as a plant photosynthesis process. Artificial light can be implemented at the seeding stage of a closed hydroponic system in a room or in areas that are rarely exposed to sunlight. Based on these problems, an RGB LED array design was made to assist lighting at the closed hydroponic system seeding stage. The design of the RGB LED array will be combined with an ESP32 microcontroller which can control and monitor light where the RGB LEDs are arranged in parallel with the number of 6 LEDs. The use of the adafruit AS7262 sensor to measure light intensity at the most optimal visible light wavelength for use in closed hydroponic systems, measurements are made by changing the variation in the measuring distance of the RGB LED with the sensor, ranging from 2 cm to 20 cm. Measurement of light intensity at wavelengths of red, green, blue by the adafruit AS7262 sensor to determine the optimal distance for pakcoy plant growth. Light intensity at the red and blue wavelengths has an influence on the growth of pakcoy plants. So that it was found that the Pakcoy plant seeding process using LEDs was better than that of planting plants without using LEDs. Plant seeding using LEDs experienced high growth and produced leaves, while plant seeding without using LEDs experienced etiolated conditions that were only able to experience high growth without producing leaves. Keywords: Hydroponics, AS7262 sensor, ESP32, LED array