An IoT Prototype for Monitoring and Control of Greenhouse Air Temperature, Nutrient Concentration, and Nutrient Solution Temperature Using DHT22, TDS, pH, and DS18B20 Sensors at Smart Farm Academy in Tapos Village, Tigaraksa District

Abstract

We developed an ESP32 prototype for a hydroponic choy sum greenhouse at Smart Farm Academy in Tapos Village. The controller reads air temperature and humidity, nutrient solution temperature, pH, and total dissolved solids (TDS). An Android application displays current readings and pump history from Firebase. We summarized the thesis test tables for 24–30 October 2026 and compared the reported functional tests with the controller logic. Five misting examples lasted 900–901 s. In the seven nutrient dosing examples, final TDS exceeded initial TDS in four cases and reached the 509–577 ppm test band in one. The pH, TDS, and misting temperature evaluation values describe test scenarios. Pump-event timestamps provide separate evidence of command timing. The thesis reports that all ten black-box scenarios passed. At exactly 36.0 °C, the inspected firmware kept an idle misting pump off. One greenhouse operator rated the application 45/50. The prototype supported remote monitoring and timed pump operation. The available tests do not establish sensor accuracy or consistent attainment of the nutrient target.