Add SMT100 Soil Moisture Sensor documentation (#2197)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
Co-authored-by: Dennis Piecha <d.piecha@ymail.com>

components/sensor/smt100.rst

@@ -0,0 +1,81 @@
+SMT100 Soil Moisture Sensor
+================================
+
+.. seo::
+    :description: Instructions for setting up SMT100 soil moisture and temperature sensor
+    :image: smt100.jpg
+    :keywords: smt100
+
+
+The SMT100 sensor platform allows you to use the SMT100 soil moisture and temperature with ESPHome.
+
+.. figure:: images/smt100.jpg
+    :align: center
+    :width: 50.0%
+
+
+The communication with this integration is done over a UART bus 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.
+
+
+.. code-block:: yaml
+
+    # 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:
+------------------------
+
+- **counts** (*Optional*): Raw measurement data from the sensor electronics (dimensionless quantity). Higher counts mean less moisture. May be used for material specific calibrations. 
+
+  - **name** (**Required**): Sensor name.
+  - All other options from :ref:`Sensor <config-sensor>`.
+
+- **Permittivity** (*Optional*): Permittivity or dielectric coefficient of the material to be measured (dimensionless quantity. Higher permittivity means higher water content. May be used for material specific calibration.
+
+  - **name** (**Required**): Sensor name.
+  - All other options from :ref:`Sensor <config-sensor>`.
+
+- **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.
+
+  - **name** (**Required**): Sensor name.
+  - All other options from :ref:`Sensor <config-sensor>`.
+
+- **moisture** (*Optional*): Soil moisture (volumetric water content in %).
+
+  - **name** (**Required**): Sensor name.
+  - All other options from :ref:`Sensor <config-sensor>`.
+
+- **voltage** (*Optional*): Supply voltage of the sensor in Volt.
+
+  - **name** (**Required**): Sensor name.
+  - All other options from :ref:`Sensor <config-sensor>`.
+  
+- **uart_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`UART Component <uart>` if you want
+  to use multiple UART buses.
+
+- **update_interval** (*Optional*, :ref:`config-time`): The interval to pull the sensor. Defaults is 60s.
+
+See Also
+--------
+
+- :doc:`/components/sensor/smt100`
+- :ref:`sensor-filters`
+- :apiref:`smt100/smt100.h`
+- :ghedit:`Edit`

index.rst

@@ -313,6 +313,7 @@ Environmental
     SHT3X-D, components/sensor/sht3xd, sht3xd.jpg, Temperature & Humidity
     SHT4X, components/sensor/sht4x, sht4x.jpg, Temperature & Humidity
     SHTCx, components/sensor/shtcx, shtc3.jpg, Temperature & Humidity
+    SMT100, components/sensor/smt100, smt100.jpg, Moisture & Temperature
     STS3X, components/sensor/sts3x, sts3x.jpg, Temperature
     TMP102, components/sensor/tmp102, tmp102.jpg, Temperature
     TMP117, components/sensor/tmp117, tmp117.jpg, Temperature
@@ -356,6 +357,7 @@ Miscellaneous
     Modbus Sensor, components/sensor/modbus_controller, modbus.png
     Nextion, components/sensor/nextion, nextion.jpg, Sensors from display
     Rotary Encoder, components/sensor/rotary_encoder, rotary_encoder.jpg
+    SMT100, components/sensor/smt100, smt100.jpg, Moisture & Temperature
     Tuya Sensor, components/sensor/tuya, tuya.png
     TX20, components/sensor/tx20, tx20.jpg, Wind speed & Wind direction