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RS485 Soil Sensor Library

This MicroPython library allows communication with the RS485 soil sensor to read:

  • 🌱 Soil Humidity (%)
  • 🌡️ Temperature (°C)
  • ⚡ Electrical Conductivity (EC, µS/cm)
  • 🧪 pH Level

Features​

  • Simple integration with MicroPython UART
  • CRC validation and sensor response handling
  • Fully open source (GPLv3)

Getting Started​

Installation​

  1. Clone the repository or download the modbus_sensor.py file.
git clone git@github.com:UNIT-Electronics-MX/unit_rs485_soil_temperature_humity_ec_ph_library_micropython.git
  1. Copy the modbus_sensor.py file to your MicroPython device.
  2. Import the ModbusSensor class in your MicroPython script.
  3. Initialize the sensor with the appropriate UART pins and baud rate.
  4. Use the get_sensor_data() method to read the sensor values.
  5. Handle the sensor data as needed.
  6. Make sure to handle exceptions and errors as needed.

Note: This library is designed for the ESP32 and may require modifications for other platforms or hardware.

Recommended to use a 5 V RS485 module for compatibility with the ESP32.

Example​

from modbusSensor.modbus_sensor import ModbusSensor
import time

sensor = ModbusSensor(tx_pin=26, rx_pin=25, baudrate=4800)

while True:
    humidity, temperature, ec, ph = sensor.get_sensor_data()
    print(f"Humidity: {humidity}% | Temperature: {temperature}°C | EC: {ec} µS/cm | pH: {ph}")
    time.sleep(1)

File Transfer using ampy

Using ampy to transfer files to ESP32​

  1. Install ampy using pip:

    pip install adafruit-ampy

  2. Connect your ESP32 to your computer via USB.

  3. Use ampy to transfer the modbus_sensor.py file to the ESP32:

    ampy --port /dev/ttyUSB0 put modbus_sensor.py

Replace /dev/ttyUSB0 with the appropriate port for your system. Remember to check the port using the ls /dev/tty* command.

  1. After transferring the file, you can access it in your MicroPython environment.

  2. To run the script, you can use the REPL or create a new script that imports modbus_sensor and uses it as shown in the example above.