141 lines
4.5 KiB
ReStructuredText
141 lines
4.5 KiB
ReStructuredText
MH-Z19 CO_2 and Temperature Sensor
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==================================
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.. seo::
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:description: Instructions for setting up MH-Z19 CO2 and temperature sensors
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:image: mhz19.jpg
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:keywords: mh-z19
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The ``mhz19`` sensor platform allows you to use MH-Z19 CO_2 and temperature sensors
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(`Revspace`_) with ESPHome.
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The CO_2 measurement also works with the MH-Z16 and MH-Z14 sensors.
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.. figure:: images/mhz19-full.jpg
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:align: center
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:width: 50.0%
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MH-Z19 CO_2 and Temperature Sensor.
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.. _Revspace: https://revspace.nl/MHZ19
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As the communication with the MH-Z19 is done using UART, you need
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to have an :ref:`UART bus <uart>` in your configuration with the ``rx_pin`` connected to the TX pin of the
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MH-Z19 and the ``tx_pin`` connected to the RX Pin of the MH-Z19 (it's switched because the
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TX/RX labels are from the perspective of the MH-Z19). Additionally, you need to set the baud rate to 9600.
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.. code-block:: yaml
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# Example configuration entry
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sensor:
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- platform: mhz19
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co2:
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name: MH-Z19 CO2 Value
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temperature:
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name: MH-Z19 Temperature
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Configuration variables:
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------------------------
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- **co2** (**Required**): The CO_2 data from the sensor in parts per million (ppm).
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All options from :ref:`Sensor <config-sensor>`.
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- **temperature** (**Required**): The information for the temperature sensor. Please note that this is
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not officially documented in the datasheet and seems to be quite inaccurate.
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All options from :ref:`Sensor <config-sensor>`.
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- **update_interval** (*Optional*, :ref:`config-time`): The interval to check the
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sensor. Defaults to ``60s``.
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- **uart_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`UART Component <uart>` if you want
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to use multiple UART buses.
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- **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for actions.
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- **automatic_baseline_calibration** (*Optional*, boolean): MH-Z19 has automatic calibration procedure.
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The automatic calibration cycle is every 24 hours after powered on.
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Set this value to ``false`` to disable ABC on boot (it's better if you use sensor indoor).
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Set this value to ``true`` to enable ABC on boot.
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Doesn't send calibration command if not set (default sensor logic will be used).
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- **warmup_time** (*Optional*, Time): The sensor has a warmup time and before that, it returns bougus readings (eg: 500ppm, 505ppm...). This setting discards readings until the warmup time happened (``NAN`` is returned). The datasheet says preheating takes 1min, but empirical tests have shown it often takes more, so the 75s default should be enough to accomodate for that.
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.. figure:: images/mhz19-pins.jpg
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:align: center
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:width: 80.0%
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Pins on the MH-Z19. Only the ones marked with a red circle need to be connected.
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.. _mhz19-calibrate_zero_action:
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``mhz19.calibrate_zero`` Action
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-------------------------------
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This :ref:`action <config-action>` executes zero point calibration command on the sensor with the given ID.
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If you want to execute zero point calibration, the MH-Z19 sensor must work in stable gas environment (400ppm)
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for over 20 minutes and you execute this function.
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.. code-block:: yaml
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on_...:
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then:
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- mhz19.calibrate_zero: my_mhz19_id
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You can provide :ref:`service <api-services>` to call it from Home Assistant
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.. code-block:: yaml
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api:
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services:
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- service: mhz19_calibrate_zero
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then:
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- mhz19.calibrate_zero: my_mhz19_id
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.. _mhz19-abc_enable_action:
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``mhz19.abc_enable`` Action
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---------------------------
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This :ref:`action <config-action>` enables automatic baseline calibration on the sensor with the given ID.
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.. code-block:: yaml
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on_...:
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then:
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- mhz19.abc_enable: my_mhz19_id
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.. _mhz19-abc_disable_action:
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``mhz19.abc_disable`` Action
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----------------------------
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This :ref:`action <config-action>` disables automatic baseline calibration on the sensor with the given ID.
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.. code-block:: yaml
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on_...:
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then:
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- mhz19.abc_disable: my_mhz19_id
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You can provide switch and control ABC from Home Assistant
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.. code-block:: yaml
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switch:
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- platform: template
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name: "MH-Z19 ABC"
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optimistic: true
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on_turn_on:
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mhz19.abc_enable: my_mhz19_id
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on_turn_off:
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mhz19.abc_disable: my_mhz19_id
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See Also
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--------
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- :ref:`sensor-filters`
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- `MH-Z19 library <https://github.com/nara256/mhz19_uart>`__ by `@nara356 <https://github.com/nara256>`__
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- :apiref:`mhz19/mhz19.h`
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- :ghedit:`Edit`
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