Návrh a implementace bezdrátového měřicího systému půdní vlhkosti

Abstract

This work deals with the design and implementation of a wireless system for measuring soil moisture in different depths simultaneously within a single installation spot. The designed soil sensor uses a capacitive principle. The soil moisture probe consists of a control board and a various number of soil sensors, whose measuring depth can be adjusted according to the current needs. The probe body is made from a polypropylene pipe of a 50 mm diameter. Both pipe ends were designed to be manufactured by 3D printers. The collected data are sent via LoRa wireless network. The LoRa gateway uses MQTT protocol for communication with the central point – the server of The Things Network (MQTT broker) which transfers the data to the InfluxDB database. The visualization of the collected values is done via Grafana. The connection of the data nodes is done by Node-RED. The processing, collection and data visualization is done via RaspberryPi 3B+ single-board computer. In addition to the original scope, other devices were constructed, such as the calibration and LoRa tester device, irrigation controller and soil auger with a supporting platform. Also, a computer program for easier probe configuration was created.