Add MCP4725 docs (#889)

* Add MCP4725 Doc

* add alterative address info

Co-authored-by: Guillermo Ruffino <glm.net@gmail.com>

components/output/mcp4725.rst

@@ -0,0 +1,86 @@
+MCP4725 Output
+==============
+
+.. seo::
+    :description: Instructions for setting up MCP4725 outputs on the ESP.
+    :image: mcp4725.png
+
+The MCP4725 output component allows to use `12bit external DAC
+<https://learn.sparkfun.com/tutorials/mcp4725-digital-to-analog-converter-hookup-guide/all>`__
+in order to have analog output(s) on any board by using I2C. Devices default address is ``0x60``
+and configurable alternative is ``0x61``.
+
+Example Usage with defaults
+***************************
+
+.. code-block:: yaml
+
+    # Set a global i2c connection
+    i2c:
+      sda: 21
+      scl: 22
+      scan: True
+
+    # Set the output with default (address: 0x60 / global i2c)
+    output:
+      - platform: mcp4725
+        id: dac_output
+
+    on_...:
+      then:
+        - output.set_level:
+            id: dac_output
+            level: 100%
+
+Example Usage with a custom configuration
+*****************************************
+
+.. code-block:: yaml
+
+    # Set a custom i2c connection
+    i2c:
+      - id: bus_a
+        sda: 21
+        scl: 22
+        scan: True
+      - id: bus_b
+        sda: 23
+        scl: 25
+        scan: True
+
+    # Set the output
+    output:
+      - platform: mcp4725
+        id: dac_output
+        address: 0x61
+        i2c_id: bus_b
+
+    on_...:
+      then:
+        - output.set_level:
+            id: dac_output
+            level: 100%
+
+Configuration variables:
+------------------------
+
+- **id** (**Required**, :ref:`config-id`): The id to use for this output component.
+- **address** (*Optional*, int): Manually specify the I2C address of
+  the DAC. Defaults to ``0x60``.
+- All other options from :ref:`Output <config-output>`.
+
+Usage with voltages higher than 3.3v
+------------------------------------
+
+In order to drive analog modules with voltages higher than 3.3v, use a `TTL bi-directionnal level
+converter <https://learn.sparkfun.com/tutorials/bi-directional-logic-level-converter-hookup-guide/all>`__
+
+Be careful about what converter you use, some of of them have channels labeled with `RX` and `TX`,
+in this case only `TX` channels are bi-directional (so you must use 2 `TX` channels for I2C to work).
+
+See Also
+--------
+
+- :doc:`/components/output/esp32_dac`
+- :doc:`/components/output/esp8266_pwm`
+- :ghedit:`Edit`

index.rst

@@ -217,6 +217,7 @@ Output Components
     TLC59208F, components/output/tlc59208f, tlc59208f.jpg
     MY9231/MY9291, components/output/my9231, my9231.svg
     SM16716, components/output/sm16716, sm16716.svg
+    MCP4725, components/output/mcp4725, mcp4725.jpg
     Custom Output, components/output/custom, language-cpp.svg
     Template Output, components/output/template, description.svg