RIASSUNTO
Farming of soft shell crab has been practiced in south-east Asian countries such as Indonesia. In the crab farming, a poor water quality increases the mortality rate of the crab in the pond. Then, in this paper, we propose a design and implementation of a water quality monitoring system for crab farming using IoT technology to give awareness to a farmer for maintaining acceptable levels of water quality in the pond. Hence, it contributes to increase the survival rate of crab and achieve higher yield of soft shell crab. Our proposed system uses a LoRa-based wireless sensor network and a lightweight Message Queuing Telemetry Transport (MQTT) protocol for exchanging messages between small embedded devices, mobile devices, and sensors. The system mainly consists of sensor node as publishers, and Raspberry pi MQTT broker, and mobile client devices as subscribers. The sensor nodes are built with small embedded devices, LoRa wireless interface, and water quality sensors, i.e. water temperature sensor, pH sensor, and salinity sensor. We also setup a web-based monitoring application using node-red dashboard for accessing water quality levels remotely.