Add cd74hc4067 docs (#1503)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
Co-authored-by: asoehlke <git@soehlke.de>

components/sensor/cd74hc4067.rst

@@ -0,0 +1,118 @@
+cd74hc4067 Analog Multiplexer
+=============================
+
+.. seo::
+    :description: Instructions for setting up cd74hc4067 Analog Multiplexer and sensors.
+    :image: cd74hc4067.jpg
+
+
+The ``cd74hc4067`` Analog Multiplexer component allows you to attach up to 16 analog input sensors to a single ADC pin.
+The component is used to activate the right multiplexer pin for each of the defined cd74hc4067 sensors.
+
+For further information about the cd74hc4067 chip see the `spec sheet  <https://www.ti.com/lit/ds/symlink/cd74hc4067.pdf>`__
+and there are also some guides around like the one from `Adam Meyer <http://adam-meyer.com/arduino/CD74HC4067>`__.
+
+Actually, the chip is bidirectional and could also be used as output, but this is not supported by the component yet.
+
+First, you need to configure the component with the digital pins that control the multiplexer. 
+Then you need to set up a voltage sensor source (e.g. :doc:`ADC sensor <adc>`) and pass it to the cd74hc4067 sensors with the ``sensor`` option.
+Each cd74hc4067 sensor is configured for one of the 16 input pins of the multiplexer.
+
+.. code-block:: yaml
+
+    # Example configuration entry
+    cd74hc4067:
+    pin_s0: D0
+    pin_s1: D1
+    pin_s2: D2
+    pin_s3: D3     
+
+    sensor:
+    - platform: adc
+        id: adc_sensor
+        pin: A0
+    - platform: cd74hc4067
+        id: adc_0
+        number: 0
+        sensor: adc_sensor
+    - platform: cd74hc4067
+        id: adc_1
+        number: 1
+        sensor: adc_sensor
+
+Component/Hub
+-------------
+
+Configuration Variables:
+************************
+
+- **pin_s0** to **pin_s3** (**Required**, :ref:`config-pin`): The I/O pins connected to the S0 to S3 channel selection pins
+- **delay** (*Optional*, :ref:`config-time`): A small delay duration needed for the chip to switch inputs, defaults to 2ms.
+
+Sensor
+------
+
+Configuration Variables:
+************************
+
+- **sensor** (**Required**, :ref:`config-id`): The source sensor to measure voltage values from, e.g. :doc:`ADC sensor <adc>`.
+- **number** (*Required*, int): The number of the cd74hc4067 input pin (0-15)
+- All other options from :ref:`Sensor <config-sensor>`.
+
+Application Example
+-------------------
+
+In this example, the component is used to measure the AC power output of two solar inverters to integrate them 
+as energy sources in `Home Assistant <https://www.home-assistant.io/docs/energy/solar-panels/>`__.
+
+For this purpose, :doc:`CT clamp sensors <ct_clamp>` are attached on each of the sensors.
+Filters are needed to calibrate the output and cut off the noise of near-zero values.
+The ``adc`` and ``cd74hc4067`` sensors updates are triggered by the ``ct_clamp`` sensors and have a very high internal update frequency.
+
+.. code-block:: yaml
+
+    cd74hc4067:
+    pin_s0: D0
+    pin_s1: D1
+    pin_s2: D2
+    pin_s3: D3     
+
+    sensor:
+    - platform: adc
+        id: adc_sensor
+        pin: A0
+        update_interval: 3600s
+    - platform: cd74hc4067
+        id: solar_1_raw
+        number: 0
+        sensor: adc_sensor
+        update_interval: 3600s
+    - platform: cd74hc4067
+        id: solar_2_raw
+        number: 1
+        sensor: adc_sensor
+        update_interval: 3600s
+    - platform: ct_clamp
+        name: "SolarPower1"
+        sensor: solar_1_raw
+        update_interval: 5s
+        unit_of_measurement: "W"
+        device_class: "power"
+        filters:
+        - lambda: "return x > 0.001 ? x * 56221 : 0;"
+    - platform: ct_clamp
+        name: "SolarPower2"
+        sensor: solar_2_raw
+        update_interval: 5s
+        unit_of_measurement: "W"
+        device_class: "power"
+        filters:
+        - lambda: "return x > 0.001 ? x * 57519 : 0;"
+
+See Also
+--------
+
+- :doc:`adc`
+- :doc:`ads1115`
+- :doc:`ct_clamp`
+- :ghedit:`Edit`

index.rst

@@ -195,6 +195,7 @@ Analogue
 
     ADC, components/sensor/adc, flash.svg, ESP internal
     ADS1115, components/sensor/ads1115, ads1115.jpg, 4-channel ADC
+    CD74HC4067, components/sensor/cd74hc4067, cd74hc4067.jpg, 16-channel analog multiplexer
     MCP3008, components/sensor/mcp3008, mcp3008.jpg, 8-channel ADC
     MCP3204, components/sensor/mcp3204, mcp3204.jpg, 4-channel ADC
     Resistance, components/sensor/resistance, omega.svg