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ESPHome - Smart Home Made Simple

SMT100 Soil Moisture Sensor

The SMT100 sensor platform allows you to use the SMT100 soil moisture and temperature with ESPHome.

The communication with this component is done via a UART using a simple ASCII protocol. You must therefore have a uart: entry in your configuration with both the TX and RX pins set to some pins on your board and the baud rate set to 9600.

# Example configuration entry
uart:
  tx_pin: TX
  rx_pin: RX
  baud_rate: 9600


sensor:
  - platform: smt100
    counts:
        name: "Counts"
    permittivity:
        name: "Permittivity"
    temperature:
        name: "Temperature"
    moisture:
        name: "Moisture"
    voltage:
        name: "Voltage"

Configuration variables

Section titled “Configuration variables”

  • counts (Optional): Raw measurement data from the sensor electronics (dimensionless quantity). Higher counts mean less moisture. May be used for material specific calibrations.

  • permittivity (Optional): Dielectric coefficient or permittivity of the material to be measured (dimensionless quantity). Higher permittivity means higher water content. May be used for material specific calibration.

  • temperature (Optional): Soil temperature in degrees Celsius. Please note that the temperature sensor is inside the black sensor enclosure and requires some time to equilibrate with the soil temperature.

  • moisture (Optional): Soil moisture (volumetric water content in %).

  • voltage (Optional): Supply voltage of the sensor in Volt.

  • uart_id (Optional, ID): Manually specify the ID of the UART Component if you want to use multiple UART buses.

  • update_interval (Optional, Time): The interval to poll the sensor. Defaults is 60s.

See Also

Section titled “See Also”