Smart Greenhouse System for Cultivation of Chili (Capsicum Annum L.) with Raspberry Pi 3B Based on MQTT Protocol

Indonesia is the largest agrarian country in the world with abundant natural resources, especially in the plantation sector. The greenhouse concept can be developed by adding a smart greenhouse system with Internet of Things (IoT) technology which can accelerate an accurate and expected plant cultivation system. This study introduces a smart greenhouse system for chili cultivation based on the IoT using website technology of NodeJS as an application interface and MongoDB as a database. The system that has been developed consists of several sensors designed to collect information related to the environmental conditions of the greenhouse. These sensors are Total Dissolved Solid/TDS (water turbidity) sensor, Dissolved Oxygen Sensor (Oxygen content), DHT11 (air temperature and humidity), pH sensor (soil pH), soil moisture sensor (soil moisture), and ultrasonic sensor (to measure the distance from the water surface). The system is developed using the Message Queuing Telemetry Transport (MQTT) protocol. Data from the sensor is delivered to the Raspberry Pi 3B and the server passes through the internet network to be stored in the database. Testing of the DHT11 sensor produces an average air temperature of 26°C and air humidity of 62% which affects the growth of chili plants while the results of testing the water pH data are 6.36 mg/l. The value of the oxygen content (Dissolved Oxygen (DO)) is 0 - 2.141 ppm while the value of the Water Level data in the reservoir is 14.7 - 19.2 cm. Testing of water turbidity uses TDS (Total Dissolved Solids) sensor. This test is performed to ensure good water quality for chili plants which is in the range of 3 - 3.5 ppm. Messages sent by MQTT have 100% delivery success rate, smaller payload size compared to HTTP, and lower device power consumption.