MH-Z19 CO_2 and Temperature Sensor ================================== .. seo:: :description: Instructions for setting up MH-Z19 CO2 and temperature sensors :image: mhz19.jpg :keywords: mh-z19 The ``mhz19`` sensor platform allows you to use MH-Z19 CO_2 and temperature sensors (`Revspace`_) with ESPHome. The CO_2 measurement also works with the MH-Z16 and MH-Z14 sensors. .. figure:: images/mhz19-full.jpg :align: center :width: 50.0% MH-Z19 CO_2 and Temperature Sensor. .. _Revspace: https://revspace.nl/MHZ19 As the communication with the MH-Z19 is done using UART, you need to have an :ref:`UART bus ` in your configuration with the ``rx_pin`` connected to the TX pin of the MH-Z19 and the ``tx_pin`` connected to the RX Pin of the MH-Z19 (it's switched because the TX/RX labels are from the perspective of the MH-Z19). Additionally, you need to set the baud rate to 9600. .. code-block:: yaml # Example configuration entry uart: rx_pin: GPIO3 tx_pin: GPIO1 baud_rate: 9600 sensor: - platform: mhz19 co2: name: "MH-Z19 CO2 Value" temperature: name: "MH-Z19 Temperature" update_interval: 60s automatic_baseline_calibration: false Configuration variables: ------------------------ - **co2** (**Required**): The CO_2 data from the sensor in parts per million (ppm). - **name** (**Required**, string): The name for the CO_2 sensor. - **id** (*Optional*, :ref:`config-id`): Set the ID of this sensor for use in lambdas. - All other options from :ref:`Sensor `. - **temperature** (**Required**): The information for the temperature sensor. Please note that this is not officially documented in the datasheet and seems to be quite inaccurate. - **name** (**Required**, string): The name for the temperature sensor. - **id** (*Optional*, :ref:`config-id`): Set the ID of this sensor for use in lambdas. - All other options from :ref:`Sensor `. - **update_interval** (*Optional*, :ref:`config-time`): The interval to check the sensor. Defaults to ``60s``. - **uart_id** (*Optional*, :ref:`config-id`): Manually specify the ID of the :ref:`UART Component ` if you want to use multiple UART buses. - **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for actions. - **automatic_baseline_calibration** (*Optional*, boolean): MH-Z19 has automatic calibration procedure. The automatic calibration cycle is every 24 hours after powered on. Set this value to ``false`` to disable ABC on boot (it's better if you use sensor indoor). Set this value to ``true`` to enable ABC on boot. Doesn't send calibration command if not set (default sensor logic will be used). .. figure:: images/mhz19-pins.jpg :align: center :width: 80.0% Pins on the MH-Z19. Only the ones marked with a red circle need to be connected. .. _mhz19-calibrate_zero_action: ``mhz19.calibrate_zero`` Action ------------------------------- This :ref:`action ` executes zero point calibration command on the sensor with the given ID. If you want to execute zero point calibration, the MH-Z19 sensor must work in stable gas environment (400ppm) for over 20 minutes and you execute this function. .. code-block:: yaml on_...: then: - mhz19.calibrate_zero: my_mhz19_id You can provide :ref:`service ` to call it from Home Assistant .. code-block:: yaml api: services: - service: mhz19_calibrate_zero then: - mhz19.calibrate_zero: my_mhz19_id .. _mhz19-abc_enable_action: ``mhz19.abc_enable`` Action --------------------------- This :ref:`action ` enables automatic baseline calibration on the sensor with the given ID. .. code-block:: yaml on_...: then: - mhz19.abc_enable: my_mhz19_id .. _mhz19-abc_disable_action: ``mhz19.abc_disable`` Action ---------------------------- This :ref:`action ` disables automatic baseline calibration on the sensor with the given ID. .. code-block:: yaml on_...: then: - mhz19.abc_disable: my_mhz19_id You can provide switch and control ABC from Home Assistant .. code-block:: yaml switch: - platform: template name: "MH-Z19 ABC" optimistic: true on_turn_on: mhz19.abc_enable: my_mhz19_id on_turn_off: mhz19.abc_disable: my_mhz19_id See Also -------- - :ref:`sensor-filters` - `MH-Z19 library `__ by `@nara356 `__ - :apiref:`mhz19/mhz19.h` - :ghedit:`Edit`