__  ___        __     _         
  /  |/  /_ _____/ /_ __(_)__  ___ 
 / /|_/ / // / _  / // / / _ \/ _ \
/_/  /_/\_, /\_,_/\_,_/_/_//_/\___/
       /___/                       
ai.iot.education.solutions.marketplace ==================================================

Ts. Mohamad Ariffin Zulkifli
ariffin@myduino.com

Industrial Soil Sensor RS485

Industrial-Grade Soil Sensor: Measure multi-parameters of soil including Temperature, Moisture, pH, EC and Nitrogen, Phosphorus and Potassium (NPK). The output signal is RS485 and can be operated broad range of voltage from 5~30 VDC.

Soil Sensors Specifications

• Operating Voltage: 5 ~ 30 VDC
• Communication Protocol: RS485
• Temperature
  • Measurement Range: -40°C ~ 80 °C
  • Measurement Accuracy: ±0.5 °C
• Moisture Content
  • Measurement Range: 0 ~ 100 %
  • Measurement Accuracy: ±3 %
• Electrical Conductivity (EC).
  • Measurement Range: 0 ~ 20000 uS/cm
  • Measurement Resolution: 1 uS/cm
• pH
  • Measurement Range: 3 ~ 9
  • Measurement Resolution: 0.1
• NPK
  • Measurement Range: 0 ~ 2999 mg/kg
  • Measurement Resolution: 1 mg/kg

RS485 Communication Details

• Data Bits: 8-bit
• Parity Bits: NO
• Stop Bit: 1
• Error Checking: CRC
• Baud Rate: 2400, 4800 (default), 9600
• Device Address: 0x01
• Function Code: 0x03
• Data Code: 16 bits

Change Device Address

The default device address is 0x01. Valid address range is 1 to 254. The address is stored in register 0x07D0 and can be changed using write function code 0x10.

• Example: Change device address from 0x01 to 0x02 (11 Bytes): 01 10 07 D0 00 01 02 00 02 42 C1

Address Code	Function Code	Register Address	Number of Registers	Byte Count	Data (New Address)	CRC
0x01	0x10	0x07 0xD0	0x00 0x01	0x02	0x00 0x02	0x42 0xC1

Note: Power cycle the sensor after changing the device address for the new address to take effect.

Change Baud Rate

The baud rate is stored in register 0x07D1 and can be changed using write function code 0x10.

• Baud Rate Values: 0x00 = 2400, 0x01 = 4800 (default), 0x02 = 9600

• Example commands from device address 0x02:

Baud Rate	Command
2400	02 10 07 D1 00 01 02 00 00 D6 21
4800	02 10 07 D1 00 01 02 00 01 17 E1
9600	02 10 07 D1 00 01 02 00 02 57 E0

Note: Power cycle the sensor after changing the baud rate for the new setting to take effect.

3-in-1 Soil Sensor Parameters

• Request Frame (8 Bytes)

Address Code	Function Code	Start Address Register	Length of Register	CRC
0x01	0x03	0x00 0x00	0x00 0x03	0x05 0xCB

Note: The Address Code and CRC bytes will differ if the device address has been changed from the default (0x01).

• Example of Response Frame (11 Bytes)

Address Code	Function Code	Byte Number	Moisture	Temperature	EC	CRC
0x01	0x03	0x06	0x01 0xEF	0x01 0x44	0x00 0x04	0xB5 0x59

• Byte Response Example Calculation
  • Moisture Content = (0x01 * 256 + 0xEF) * 0.1 = 49.5 %
  • Temperature = (0x01 * 256 + 0x44) * 0.1 = 32.4 °C
  • EC = (0x00 * 256 + 0x04) = 4 uS/cm

4-in-1 Soil Sensor Parameters

• Request Frame (8 Bytes)

Address Code	Function Code	Start Address Register	Length of Register	CRC
0x01	0x03	0x00 0x00	0x00 0x04	0x44 0x09

Note: The Address Code and CRC bytes will differ if the device address has been changed from the default (0x01).

• Example of Response Frame (13 Bytes)

Address Code	Function Code	Byte Number	Moisture	Temperature	EC	pH	CRC
0x01	0x03	0x08	0x02 0x62	0x01 0x67	0x00 0x06	0x00 0x37	0xC2 0x06

• Byte Response Example Calculation
  • Moisture Content = (0x02 * 256 + 0x62) * 0.1 = 61.0 %
  • Temperature = (0x01 * 256 + 0x67) * 0.1 = 35.9 °C
  • EC = (0x00 * 256 + 0x06) = 6 uS/cm
  • pH = (0x00 * 256 + 0x37) * 0.1 = 5.5

7-in-1 Soil Sensor Parameters

• Request Frame (8 Bytes)

Address Code	Function Code	Start Address Register	Length of Register	CRC
0x01	0x03	0x00 0x00	0x00 0x07	0x04 0x08

Note: The Address Code and CRC bytes will differ if the device address has been changed from the default (0x01).

• Example of Response Frame (19 Bytes)

Address Code	Function Code	Byte Number	Moisture	Temperature	EC	pH	Nitrogen (N)	Phosphorus (P)	Potassium (K)	CRC
0x01	0x03	0x0E	0x01 0xE6	0x01 0x55	0x05 0xDC	0x01 0x34	0x00 0x20	0x00 0x25	0x00 0x30	0x04 0x08

• Byte Response Example Calculation
  • Moisture Content = (0x01 * 256 + 0xE6) * 0.1 = 48.6 %
  • Temperature = (0x01 * 256 + 0x55) * 0.1 = 34.1 °C
  • EC = (0x05 * 256 + 0xDC) = 1500 uS/cm
  • pH = (0x01 * 256 + 0x34) * 0.1 = 3.08
  • N = (0x00 * 256 + 0x20) = 32 mg/kg
  • P = (0x00 * 256 + 0x25) = 37 mg/kg
  • K = (0x00 * 256 + 0x30) = 48 mg/kg

Contact Us

• Call or WhatsApp 6012-3859151
• Website: Myduino