add docs for new EZO sensor circuits (#727)

Co-authored-by: Samuel Sieb <samuel@sieb.net>

components/sensor/ezo.rst

@@ -0,0 +1,65 @@
+EZO sensor circuits
+===================
+
+.. seo::
+    :description: Instructions for setting up EZO sensor circuits in esphome
+    :image: ezo-ph-circuit.png
+    :keywords: ezo ph ec rtd sensor circuit esphome
+
+The ``ezo`` sensor platform allows you to use your EZO sensor circuits with
+ESPHome. The :ref:`I²C Bus <i2c>` is
+required to be set up in your configuration for this sensor to work.
+
+.. figure:: images/ezo-ph-circuit.png
+    :align: center
+    :width: 80.0%
+
+.. code-block:: yaml
+
+    # Example configuration entry
+    sensor:
+
+      - platform: ezo
+        id: ph_ezo
+        address: 99
+        unit_of_measurement: "pH"
+        update_interval: 10s
+
+      - platform: ezo
+        id: rtd_ezo
+        name: "RTD Temperature"
+        address: 102
+        accuracy_decimals: 2
+        unit_of_measurement: "°C"
+        update_interval: 10s
+
+
+Configuration variables:
+------------------------
+
+- **address** (**Required**, int): Specify the I²C address of the sensor.
+- **update_interval** (*Optional*, :ref:`config-time`): The interval to check the
+  sensor. Defaults to ``60s``.
+- **id** (*Optional*, :ref:`config-id`): Set the ID of this sensor for use in lambdas.
+- All other options from :ref:`Sensor <config-sensor>`.
+
+lambda calls
+------------
+
+From :ref:`lambdas <config-lambda>`, you can set the temperature compensation for the
+sensors that support that option.
+
+- ``set_tempcomp_value()``: Send the given temperature to the sensor.
+
+  .. code-block:: cpp
+
+      // Within a lambda, set the temperature compensation value from the temperature sensor
+      id(ph_ezo).set_tempcomp_value(id(rtd_ezo).state);
+
+
+See Also
+--------
+
+- :ref:`sensor-filters`
+- :apiref:`ezo/ezo.h`
+- :ghedit:`Edit`

index.rst

@@ -114,6 +114,7 @@ Sensor Components
     DHT12, components/sensor/dht12, dht12.jpg
     Duty Cycle, components/sensor/duty_cycle, percent.svg
     ESP32 Hall Sensor, components/sensor/esp32_hall, magnet.svg
+    EZO sensor circuits, components/sensor/ezo, ezo-ph-circuit.png
     HDC1080, components/sensor/hdc1080, hdc1080.jpg
     HLW8012, components/sensor/hlw8012, hlw8012.svg
     HMC5883L, components/sensor/hmc5883l, hmc5883l.jpg