add emc2101 component (#2709)

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

components/emc2101.rst

@@ -0,0 +1,138 @@
+EMC2101 Fan Controller and Temperature sensor
+=============================================
+
+.. seo::
+    :description: Instructions for setting up EMC2101 fan controller and temperature sensor in ESPHome.
+    :image: emc2101.jpg
+    :keywords: EMC2101
+
+The ``emc2101`` component allows you to control a cooling fan from ESPHome (`datasheet <https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/EMC2101-Data-Sheet-DS20006703.pdf>`__). It also provides temperature
+sensors and a tachometer. The fan can be controlled either by a PWM signal or by outputing a DC voltage
+using its DAC.
+
+The :ref:`I²C Bus <i2c>` is required to be set up in your configuration for this sensor to work.
+
+.. figure:: images/emc2101-full.png
+    :align: center
+    :width: 50.0%
+
+    EMC2101 Fan Controller and Temperature sensor
+
+.. note::
+
+    Original image at https://learn.adafruit.com/assets/97827 created by 
+    by user `Bryan Siepert <https://learn.adafruit.com/u/siddacious>`__ under
+    `Creative Commons BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0/>`__ and modified
+    for this documentation.
+
+
+
+EMC2101 Component
+-----------------
+
+.. code-block:: yaml
+
+    # Example configuration entry
+    emc2101:
+      pwm:
+        resolution: 8
+
+
+Configuration variables:
+************************
+
+- **address** (*Optional*, int): Manually specify the I²C address of the sensor. Defaults to ``0x4C``.
+- **inverted** (*Optional*, boolean): Inverts the output so 0 means 100% duty cycle and 1 means 0%.  Defaults to ``false``.
+- **pwm** (*Optional*): Enable PWM output.
+
+  - **resolution** (*Optional*, int): Determines effective resolution and the frequency of the PWM signal. Defaults to ``23``.
+  - **divider** (*Optional*, int): Value for the frequency divider. Defaults to ``1``.
+
+- **dac** (*Optional*): Enable DAC output.
+
+  - **conversion_rate** (*Optional*, string): The number of digital to analog conversions perfomed per second. One of ``1/16``, ``1/8``,
+    ``1/4``, ``1/2``, ``1``, ``2``, ``4``, ``8``, ``16``, ``32``. Defaults to ``16``.
+
+
+The PWM signal frequency is determined by the following formula:
+
+.. math::
+
+    \text{PWM Frequency} = \frac{360KHz}{2 \times resolution \times divider}
+
+And the PWM resolution, the steps in the duty cycle, is calculated by the following formula:
+
+.. math::
+
+    \text{PWM resolution} = \frac{100\%}{2 \times resolution}
+
+So, with the default values the PWM signal will have a frequency of 7.83KHz and a resolution of 2.17%. The maximum
+resolution value is ``31`` which will configure a frequency of 5.81KHz with a resolution of 1.61%.
+
+
+
+EMC2101 Output
+--------------
+
+.. code-block:: yaml
+
+    output:
+      - platform: emc2101
+        id: fan_duty_cycle
+
+
+Configuration variables:
+************************
+
+- **id** (**Required**, :ref:`config-id`): The ID to use for code generation, and for reference by dependent components.
+
+.. note::
+
+    When using the ``emc2101`` output with a :doc:`/components/fan/speed` it is advised to configure the **speed_count**
+    as twice the **resolution** so the number of speeds in the fan matches the number of steps in the fan controller.
+
+
+
+EMC2101 Sensors
+---------------
+
+.. code-block:: yaml
+
+    sensor:
+      - platform: emc2101
+        internal_temperature:
+          id: internal_temperature_sensor
+          name: "Internal Temperature Sensor"
+        speed:
+          id: speed_sensor
+          name: "Speed Sensor"
+        duty_cycle:
+          id: duty_cycle_sensor
+          name: "Duty Cycle Sensor"
+        update_interval: 5s
+
+
+Configuration variables:
+************************
+- **internal_temperature** (*Optional*): The internal temperature sensor. 
+  All options from :ref:`Sensor <config-sensor>`.
+
+- **external_temperature** (*Optional*): The external temperature sensor. More accurate but it needs an additional transistor to be installed. 
+  All options from :ref:`Sensor <config-sensor>`.
+
+- **speed** (*Optional*): The fan speed sensor in RPMs. 
+  All options from :ref:`Sensor <config-sensor>`.
+
+- **duty_cycle** (*Optional*): Duty cycle sensor. 
+  All options from :ref:`Sensor <config-sensor>`.
+
+- **update_interval** (*Optional*, :ref:`config-time`): The interval to check the sensor. Defaults to ``60s``.
+
+
+See Also
+--------
+
+- :ref:`config-sensor`
+- :doc:`/components/fan/speed`
+- :apiref:`emc2101/emc2101.h`
+- :ghedit:`Edit`

index.rst

@@ -308,6 +308,7 @@ Environmental
     DHT, components/sensor/dht, dht.jpg, Temperature & Humidity
     DHT12, components/sensor/dht12, dht12.jpg, Temperature & Humidity
     DPS310, components/sensor/dps310, dps310.jpg, Temperature & Pressure
+    EMC2101, components/emc2101, emc2101.jpg, Temperature
     ENS210, components/sensor/ens210, ens210.jpg, Temperature & Humidity
     HDC1080, components/sensor/hdc1080, hdc1080.jpg, Temperature & Humidity
     HTE501, components/sensor/hte501, HTE501.png, Temperature & Humidity
@@ -537,6 +538,7 @@ Output Components
     BP5758D, components/output/bp5758d, bp5758d.svg
     X9C Potentiometer, components/output/x9c, x9c.jpg
     GP8403, components/output/gp8403, gp8403.svg
+    EMC2101, components/emc2101, emc2101.jpg
 
 Light Components
 ----------------