Add MAX31865, update MAX31855 (#399)

* Add MAX31865, update MAX31855.

Update documentation for the new MAX31865 sensor and the improvements to the
MAX31855 sensor.

* Update MAX31865 filter parameter type.

It is actually a enum (string?), not a time value.

* MAX31855 & MAX31865 documentation improvements.

@OttoWinter suggested some good fixes, implementing those.

components/sensor/max31855.rst

@@ -8,7 +8,7 @@ MAX31855 K-Type Thermocouple Temperature Sensor
 The ``max31855`` temperature sensor allows you to use your max31855 thermocouple
 temperature sensor (`datasheet <https://datasheets.maximintegrated.com/en/ds/MAX31855.pdf>`__) with ESPHome
 
-As the communication with the MAX66775 is done using SPI, you need
+As the communication with the MAX31855 is done using SPI, you need
 to have an :ref:`spi bus <spi>` in your configuration with the **miso_pin** set (mosi is not required).
 
 Connect ``GND`` to ``GND``, ``VCC`` to ``3.3V`` and the other three ``MISO`` (or ``SO`` for short),
@@ -37,9 +37,8 @@ Configuration variables:
 - **name** (**Required**, string): The name for the temperature sensor.
 - **cs_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The Chip Select pin of the SPI interface.
 - **update_interval** (*Optional*, :ref:`config-time`): The interval to check the sensor. Defaults to ``60s``.
-
-- **spi_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`SPI Component <spi>` if you want
-  to use multiple SPI buses.
+- **reference_temperature** (*Optional*, :ref:`Sensor <config-sensor>`): Access the internal temperature sensor of the MAX31855. Requires a **name** and/or **id**.
+- **spi_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`SPI Component <spi>` if you want to use multiple SPI buses.
 - **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation.
 - All other options from :ref:`Sensor <config-sensor>`.
 
@@ -51,6 +50,7 @@ See Also
 - :doc:`dht`
 - :doc:`adc`
 - :doc:`max6675`
+- :doc:`max31865`
 - `MAX31855 Library <https://github.com/adafruit/Adafruit-MAX31855-library>`__ by `Adafruit <https://www.adafruit.com/>`__
 - :apiref:`max31855/max31855.h`
 - :ghedit:`Edit`

components/sensor/max31865.rst

@@ -0,0 +1,70 @@
+MAX31865 Platinum RTD Temperature Sensor
+========================================
+
+.. seo::
+    :description: Instructions for setting up MAX31865 platinum RTD temperature sensors.
+    :image: max31865.jpg
+
+The ``max31865`` temperature sensor allows you to use your max31865 RTD
+temperature sensor (`datasheet <https://datasheets.maximintegrated.com/en/ds/MAX31865.pdf>`__) with ESPHome
+
+.. figure:: images/max31865-full.jpg
+    :align: center
+    :width: 50.0%
+
+    MAX31865 Sensor. Image by `Adafruit`_
+
+.. _Adafruit: https://www.adafruit.com/product/3328
+
+As the communication with the MAX31865 is done using SPI, you need
+to have an :ref:`spi bus <spi>` in your configuration with both **miso_pin** and **mosi_pin** set.
+
+- ``VIN`` connects to 5V (``3V3`` will output 3.3V), or directly connect ``3V3`` to 3.3V
+- ``GND`` connects to ground
+- ``CLK`` connects to the SPI **clk_pin**
+- ``SDO`` connects to the SPI **miso_pin**
+- ``SDI`` connects to the SPI **mosi_pin**
+- ``CS`` connects to a free GPIO pin
+- ``RDY`` is not used by ESPHome
+
+.. code:: yaml
+
+    # Example configuration entry
+    spi:
+      miso_pin: D0
+      mosi_pin: D1
+      clk_pin: D2
+
+    sensor:
+      - platform: max31865
+        name: "Living Room Temperature"
+        cs_pin: D3
+        reference_resistance: 430 Ω
+        rtd_nominal_resistance: 100 Ω
+
+Configuration variables:
+------------------------
+
+- **name** (**Required**, string): The name for the temperature sensor.
+- **cs_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The Chip Select pin of the SPI interface.
+- **update_interval** (*Optional*, :ref:`config-time`): The interval to check the sensor. Defaults to ``60s``.
+- **reference_resistance** (**Required**, float): Reference resistor on the PCB. Adafruit's PT100 (#3328) uses 430 Ω, their PT1000 (#3648) uses 4300 Ω.
+- **rtd_nominal_resistance** (**Required**, float): Nominal resistance of the RTD at 0°C. PT100 is 100 Ω, PT1000 is 1000 Ω.
+- **mains_filter** (*Optional*, string): The mains power frequency to reject (``50 Hz`` or ``60 Hz``). Defaults to ``60 Hz``.
+- **rtd_wires** (*Optional*, int): The number of RTD wires. Be sure to solder board jumpers to match! Defaults to ``4``.
+- **spi_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`SPI Component <spi>` if you want to use multiple SPI buses.
+- **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation.
+- All other options from :ref:`Sensor <config-sensor>`.
+
+See Also
+--------
+
+- :ref:`sensor-filters`
+- :doc:`dallas`
+- :doc:`dht`
+- :doc:`adc`
+- :doc:`max6675`
+- :doc:`max31855`
+- `MAX31865 Library <https://github.com/adafruit/Adafruit_MAX31865>`__ by `Adafruit <https://www.adafruit.com/>`__
+- :apiref:`max31865/max31865.h`
+- :ghedit:`Edit`

index.rst

@@ -120,6 +120,7 @@ Sensor Components
     Integration, components/sensor/integration, sigma.svg
     HTU21D, components/sensor/htu21d, htu21d.jpg
     MAX31855, components/sensor/max31855, max31855.jpg
+    MAX31865, components/sensor/max31865, max31865.jpg
     MAX6675, components/sensor/max6675, max6675.jpg
     MH-Z19, components/sensor/mhz19, mhz19.jpg
     MPU6050, components/sensor/mpu6050, mpu6050.jpg