RS485 Soil NPK Sensor IP68 5-30V

The RS485 soil sensor from DFRobot measures nitrogen (N), phosphorus (P) and potassium (K) directly in the soil and outputs the values digitally via RS485 with Modbus-RTU. The probe made of 316 stainless steel is vacuum-potted in black flame-retardant epoxy resin (IP68) and can remain permanently in soil or water. The supply range is 5 to 30 V DC. For an Arduino UNO, DFRobot names the RS485 Shield as interface.

Important: According to DFRobot, the NPK values are reference values only and not as accurate as measurements with laboratory instruments.

Recommended Accessories:

• RS485 Shield for Arduino UNO
• DFRobot RS485-to-UART Module with Active Isolation
• USB to RS485 Converter Module
• SenseCAP S2100 LoRaWAN Data Logger

Features:

• Nitrogen (N), phosphorus (P) and potassium (K) each 0 to 2999 mg/kg, resolution 1 mg/kg, accuracy ≤5 % (reference value)
• RS485 with Modbus-RTU, factory address 1, 9600 baud (2400, 4800 and 9600 baud selectable)
• Probe made of 316 stainless steel, vacuum-potted in epoxy resin, protection class IP68, for permanent installation in the soil
• 2 m cable with four wires: brown VCC, black GND, yellow RS485-A, blue RS485-B
• Installation according to DFRobot: insert the needles fully into the soil, do not bend them, do not pull on the cable, protect from direct sunlight

Application Examples:

• Controlling irrigation in the garden, greenhouse or field based on measured values
• Long-term measurement in the soil with data logger or LoRaWAN node
• Monitoring substrate and hydroponics
• Experiments in school, research and agriculture

Documentation:

• Wiki DFRobot SEN0605
• Arduino example with RS485 Shield (DFRobot Wiki)
• Modbus registers and installation (DFRobot Wiki)
• Soil sensor selection guide by DFRobot

Technical Data:

• Manufacturer: DFRobot
• Manufacturer SKU: SEN0605
• Supply: 5 to 30 V DC
• Power consumption: 0.15 W at 12 V
• Interface: RS485, Modbus-RTU
• Address: 1 to 254, factory setting 1
• Baud rate: 9600 baud factory setting, 2400 or 4800 baud selectable
• N, P, K: each 0 to 2999 mg/kg (mg/L), resolution 1 mg/kg
• NPK accuracy: ≤5 %, reference value only
• Protection class: IP68
• Probe: 316 stainless steel, corrosion-resistant special electrode
• Potting: black flame-retardant epoxy resin
• Operating temperature: 0 to 55 °C
• Cable length: 2 m
• Dimensions: 123 × 45 × 15 mm
• Weight: 194 g

Scope of Delivery:

• 1× RS485 soil sensor NPK with 2 m cable