RS485 Soil pH, Moisture, Temperature Monitoring Sensor for Hydroponics (IP68, 5-30V)

This industrial-grade RS485 sensor provides real-time monitoring of pH, moisture, and temperature in soil and hydroponic setups. Built for agricultural automation, research, and hobbyist projects, it integrates cleanly with microcontrollers such as the Arduino Uno via Modbus-RTU.

Modbus-RTU RS485 communication

The sensor transmits data using standard Modbus-RTU over an RS485 interface, enabling straightforward connection to an Arduino Uno via a TTL-to-RS485 expansion module. This serial protocol ensures stable data transfer over extended cable runs in automated irrigation networks.

316 stainless steel probes

Equipped with 316 stainless steel probe electrodes, the sensor resists rust, salt-alkali corrosion, and long-term electrolysis. The durable metal prongs can be buried continuously in various soil types or submerged in nutrient solutions.

Multi-parameter sensing range

The unit measures moisture from 0 to 100%, temperatures from -40°C to +80°C, and pH levels across a 3 to 9 pH span with 0.1 pH resolution. These metrics allow precise control over root zone moisture and acid-base reactions to protect plant health.

Versatile growing and testing applications

Designed for hydroponics, greenhouses, and soil-less cultivation, the probe is equally suited to grain storage, pasture monitoring, and scientific soil testing. It delivers fast-response data to help balance nutrient solutions and optimise watering cycles.

IP68 vacuum-sealed casing

Encased in black flame-retardant epoxy resin with full vacuum sealing, the sensor carries an IP68 waterproof rating. It operates in environmental temperatures ranging from -20°C to +60°C and includes a 2-metre connection lead.

Wide 5-30V power supply

With an operating voltage range of DC 5V to 30V and power consumption of just 0.5W at 24V, the unit easily interfaces with both 5V development boards and standard 12V or 24V industrial power supplies.

Downloads & documentation

• Product wiki (DFRobot)