DEVELOPMENT AND EVALUATION OF A SMART GREENHOUSE SYSTEM FOR LETTUCE CULTIVATION WITH REAL-TIME SMARTPHONE MONITORING

Abstract

This research study investigated the control of temperature, relative humidity, and soil moisture in a misting greenhouse system using an Arduino control unit to regulate the operation of electrical devices via a smartphone for growing lettuce. In addition, sensors for measuring temperature, relative humidity, and soil moisture were employed to monitor and automatically control the system, with real-time data accessible through a smartphone. The system utilized a 24Vdc, 6.9 bar high-pressure water pump with 12 misting nozzles of 0.6 mm and a single 8-inch 30-Watt exhaust fan. All were connected through the Blynk IoT application via Wi-Fi. The experimental results showed that the system could maintain an average temperature of 30.5°C within the greenhouse, reduce the ambient temperature by an average of 3.48°C, and increase relative humidity by up to 5.0%. The average of relative humidity during the test period was 1.05%. Additionally, the system was able to maintain a stable soil moisture level with an average of 27.5%. The study demonstrated that the system could effectively control temperature, humidity, and soil moisture within the optimal range for lettuce cultivation. Due to the measurement of various system parameters, it was found that the sensors used had a margin of error of approximately ±0.58°C for temperature, ±3.42% RH for relative humidity, and ±2.93% for soil moisture. These errors should be taken into consideration when analyzing the experimental results and designing future systems to enhance the accuracy of control.