RS485 MODBUS-RTU Soil NPK Measure Sensor

1. Example Code for Arduino-Read Soil NPK

This project demonstrates how to use an Arduino UNO R3 with the RS485 Shield for Arduino to read nitrogen (N), phosphorus (P), and potassium (K) values from the SEN0605 RS485 Soil Sensor. Users will learn to establish RS485 communication using the ModBus-RTU protocol, send sensor query commands, and parse returned data to obtain soil nutrient values.

Reference

The article explains the ModBus-RTU communication protocol, outlining communication parameters, data frame formats, and examples for sensor data reading, complemented by installation guidelines.

Parameter	Specification
Power supply voltage	DC5-30V
Power consumption	0.15W@12V
Output mode	RS485
Detection parameters	Nitrogen（N）、Phosphorus（P）、Potassium（K）
NPK range	0-2999mg/kg (mg/L)
Resolution	1mg/kg (mg/L)
Accuracy	≤5% (subject to the actual measuring instrument)
Protection level	IP68
Probe material	anti-corrosion special electrode
Sealing material	black flame retardant epoxy resin
Working temperature	-40°C~+60°C
Size	123x45x15mm
Cable length	2m

Num	Label	Description
Brown line	VCC	Power input positive pole, DC5-30V power supply
Black line	GND	Power ground wire
Yellow line	485-A	RS485 data line A
Blue line	485-B	RS485 data line B

RS485 MODBUS-RTU Soil NPK Measure Sensor

Specification

Pinout