LTR390 UV and Ambient Light Sensor ================================================== .. seo:: :description: Instructions for setting up LTR390 UV and light sensor :image: ltr390.jpg The ``ltr390`` sensor platform allows you to use your LTR390 UV and ambient light sensor (`datasheet `__, `Adafruit`_) with ESPHome. The :ref:`I²C Bus ` is required to be set up in your configuration for this sensor to work. .. figure:: images/ltr390-full.jpg :align: center :width: 80.0% .. _Adafruit: https://www.adafruit.com/product/4831 .. code-block:: yaml sensor: - platform: ltr390 uv: name: "UV Index" light: name: "Light" Configuration variables: ------------------------ - **uv_index** (*Optional*): UV index (UVI). All options from :ref:`Sensor `. - **uv** (*Optional*): Sensor counts for the UV sensor (#). All options from :ref:`Sensor `. - **light** (*Optional*): Lux of ambient light (lx). All options from :ref:`Sensor `. - **ambient_light** (*Optional*): Sensor counts for the Ambient light sensor (#). All options from :ref:`Sensor `. - **gain** (*Optional*, string): Adjusts the sensitivity of the sensor. A larger value means higher sensitivity. See table below for details. Default is ``"X3"``. - **resolution** (*Optional*, int): ADC resolution. Higher resolutions require longer sensor integration times. See table below for details. Default is ``18``. - **window_correction_factor** (*Optional*, float): Window correction factor. Use larger values when using under tinted windows. Default is ``1.0``, must be ``>= 1.0``. - **address** (*Optional*, int): Manually specify the I²C address of the sensor. Default is `0x53`. - **update_interval** (*Optional*, :ref:`config-time`): The interval to check the sensor. Defaults to ``60s``. It is recommended that the update interval is at least 1 second since updates can take up to 800ms when using a high resolution value. Lux and UVI Formulas -------------------- .. math:: \text{lux} = \frac{0.6 \times \text{als}}{\text{gain} \times \text{int}} \times \text{wfac} .. math:: \text{UVI} = \frac{\text{uv}}{\text{sensitivity}} \times \text{wfac} where: - ``als`` and ``uv`` are the sensor values - ``gain`` is the amount of gain, see the table below for details - ``int`` is the integration time in 100s of ms and is tied to the resolution, see the table below for details - ``sensitivity`` has the value ``2300`` and is the sensor's count per UVI - ``wfac`` is the window correction factor Gain ---- .. list-table:: :widths: 25 25 :header-rows: 1 * - Gain Parameter - gain * - X1 - 1 * - X3 - 3 * - X6 - 6 * - X9 - 9 * - X18 - 18 Resolution ---------- .. list-table:: Resolution :widths: 25 25 10 :header-rows: 1 * - Resolution Parameter (bits) - Integration Time (ms) - int * - 16 - 25 - 0.25 * - 17 - 50 - 0.5 * - 18 - 100 - 1 * - 19 - 200 - 2 * - 20 - 400 - 4 See Also -------- - :doc:`/components/sensor/bh1750` - :doc:`/components/sensor/tsl2561` - :doc:`/cookbook/temt6000` - :ref:`sensor-filters` - :apiref:`ltr390/ltr390.h` - :ghedit:`Edit`