RS485 soil sensor
Christy_2211 2025-02-06 13:41:03 741 Views2 Replies I am using the RS485 Soil Sensor (SKU: SEN0600) in my project, and I need to connect multiple sensors to the same RS485 bus. By default, the sensor has an address of 0x01. Is there a way to modify this factory default address to assign unique addresses to each sensor? If so, what are the steps or commands required to change it? Any guidance or documentation would be greatly appreciated.
You can try this code to change the address.
#include <SoftwareSerial.h>
#define TX_PIN 3 // TX pin to MAX485 DI
#define RX_PIN 2 // RX pin from MAX485 RO
#define DE_RE 4 // RS485 Direction Control
SoftwareSerial rs485Serial(RX_PIN, TX_PIN); // RX, TX
void sendCommand(byte *cmd, int length) {
digitalWrite(DE_RE, HIGH); // Enable RS485 Transmit
delay(10);
rs485Serial.write(cmd, length);
delay(10);
digitalWrite(DE_RE, LOW); // Disable RS485 Transmit (Enable Receive)
}
void setup() {
Serial.begin(9600); // Debugging Serial Monitor
rs485Serial.begin(9600); // RS485 Baud Rate
pinMode(DE_RE, OUTPUT);
digitalWrite(DE_RE, LOW); // Default to Receive Mode
// Modbus RTU Command to Change Address from 0x01 to 0x02
byte changeAddressCmd[] = {
0x01, 0x06, 0x00, 0x03, 0x00, 0x02, 0x79, 0x84
};
Serial.println("Changing RS485 Sensor Address from 0x01 to 0x02...");
sendCommand(changeAddressCmd, sizeof(changeAddressCmd));
delay(1000);
Serial.println("Address Change Sent! Now testing new address...");
}
void loop() {
byte requestDataCmd[] = {
0x02, 0x03, 0x00, 0x00, 0x00, 0x02, 0xC4, 0x39
};
sendCommand(requestDataCmd, sizeof(requestDataCmd));
delay(500); // Wait for response
while (rs485Serial.available()) {
Serial.print(rs485Serial.read(), HEX);
Serial.print(" ");
}
Serial.println();
delay(2000);
}
If you want to make a simple soil moisture sensor, you may try this:
https://www.pcbway.com/project/shareproject/Customized_LM393D_Soil_Moisture_Sensor_Board_4985ec99.html
lia.ifat Usually, addresses are changed by configuring registers. The specific register address and operation method need to refer to the sensor's data manual.
sun.haihui 
