Soil sensor node

A solar-powered soil probe in a 3D-printed case, built to be tested in the open field next season.

The node reads soil moisture, temperature and conductivity through a steel RS485 probe, and estimates nutrients from conductivity, and sends the readings over LoRa radio, so it needs no mobile data. A single 18650 battery, topped up by a small solar panel on the lid, keeps it running.

The case is printed in ASA, which holds its shape in strong sun; PLA softens and ABS turns brittle in UV. An O-ring seal, cable glands and a breathable vent are designed to keep out water. A cheaper mini-prototype logging one test pot comes first.