AMS AS3935 Franklin Lightning Sensor
====================================

.. seo::
    :description: Instructions for setting up AS3935 lightning sensor
    :image: images/as3935.jpg
    :keywords: as3935

The ``as3935`` sensor platform allows you to use your AS3935 sensor
(`AliExpress`_, `AMS_AS3935`_)
in order to get notified when a thunderstorm is getting close.

The AS3935 can detect the presence of lightning activity and provide an estimation
on the distance to the head of the storm. The chip issues a notification through an interrupt
pin.

The AS3935 can be configured to use either the SPI **or** I²C protocol for data communication.
First choose which communication method you want to use for the sensor, set the SI pin for the appropriate
level and set up the ESPhome integration for the chosen communication method.

Module Pins
-----------

============  ===============================================================
 Module Pin   Description
============  ===============================================================
VCC/VDD       Positive supply voltage
GND           Ground
SCL           I²C clock bus or SPI clock bus (according to SI setting)
MOSI          I²C data bus or SPI data input bus (according to SI setting)
MISO          SPI data output bus
CS            Chip Select (active low)
SI            Select Interface (GND → SPI or VDD → I²C)
IRQ           Interrupt (out)
EN_V          Voltage Regulator Enable
A0            I²C address selection LSB
A1            I²C address selection MSB
============  ===============================================================

.. figure:: images/as3935.jpg
    :align: center
    :width: 50.0%

    AS3935 Lightning Sensor.

.. _AliExpress: https://de.aliexpress.com/af/as3935.html?SearchText=as3935
.. _AMS_AS3935: https://ams.com/as3935

.. code-block:: yaml

    # Example configuration for SPI (decide for one!)
    as3935_spi:
      cs_pin: GPIO12
      irq_pin: GPIO13
    # Example configuration for I²C (decide for one!)
    as3935_i2c:
      irq_pin: GPIO12

    # Example configuration for creating sensors
    sensor:
      - platform: as3935
        lightning_energy:
          name: "Lightning Energy"
        distance:
          name: "Distance Storm"
    binary_sensor:
      - platform: as3935
        name: "Storm Alert"


Configuration variables (shared):
---------------------------------

- **irq_pin** (**Required**, :ref:`config-pin`): The IRQ pin, which indicates if a lightning strike has been detected.
- **indoor** (*Optional*, boolean): Indicates if the sensor is used indoor. Defaults to ``true``.
- **noise_level** (*Optional*, integer): Noise floor level is compared to known reference voltage.
  If this level is exceeded the chip will issue an interrupt to the IRQ pin, broadcasting that it can not
  operate properly due to noise (INT_NH). Defaults to ``2``.
- **spike_rejection** (*Optional*, integer): Helps to differentiate between real events and actual lightning.
  Increasing this value increases robustness at the cost of sensitivity to distant events. Defaults to ``2``.
- **lightning_threshold** (*Optional*, integer): The number of lightnings that must appear in a 15-minute time
  window before a lightning storm is detected.
  15 minutes is the window of time before the number of detected lightning events is reset.
  The number of lightning strikes can be set to 1,5,9, or 16. Defaults to ``1``.
- **mask_disturber** (*Optional*, boolean): This setting will return whether or not disturbers trigger
  the IRQ Pin. Defaults to ``false``.
- **div_ratio** (*Optional*, integer): The antenna is designed to resonate at 500kHz and so can be tuned
  with the following setting. The accuracy of the antenna must be within 3.5 percent of that value for
  proper signal validation and distance estimation. Defaults to ``0``.
- **capacitance** (*Optional*, integer): This setting will add capacitance to the series RLC antenna on the product
  to help tune its resonance. The datasheet specifies being within 3.5 percent of 500kHz to get optimal lightning
  detection and distance sensing. It's possible to add up to 120pF in steps of 8pF to the antenna. Defaults to ``0``.

- **watchdog_threshold** (*Optional*, integer): Determines the threshold for events that trigger the IRQ pin.
  Defaults to ``2``.

Sensor entries:

- **lightning_energy** (*Optional*): Lightning energy value. According to the datasheet this is only a pure value that doesn't have any physical meaning.

  - **name** (**Required**, string): The name for the lightning energy sensor.
  - **id** (*Optional*, :ref:`config-id`): Set the ID of this sensor for use in lambdas.
  - All other options from :ref:`Sensor <config-sensor>`.
- **distance** (*Optional*): Distance in km to the front of the storm and not the distance to a lightning strike.

  - **name** (**Required**, string): The name for the distance sensor.
  - **id** (*Optional*, :ref:`config-id`): Set the ID of this sensor for use in lambdas.
  - All other options from :ref:`Sensor <config-sensor>`.
- **binary sensor** (*Optional*): Binary sensor that indicates if a lightning strike was detected.

  -  **name** (**Required**, string): The name of the binary sensor.
  -  **id** (*Optional*,
     :ref:`config-id`): Manually specify
     the ID used for code generation.
  -  All other options from :ref:`Binary Sensor <config-binary_sensor>`.

Configuration variables (I²C):
-------------------------------

Use this if you want to use your AS3935 in I²C mode.

.. code-block:: yaml

    # Example configuration for I²C (decide for one!)
    as3935_i2c:
      irq_pin: GPIO12
    # Example shared configuration
    sensor:
      - platform: as3935
        lightning_energy:
          name: "Lightning Energy"
        distance:
          name: "Distance Storm"
    binary_sensor:
      - platform: as3935
        name: "Storm Alert"

- **address** (*Optional*, int): Manually specify the I²C address of
  the sensor. Defaults to ``0x03`` (``A0` and ``A1`` pins pulled low).
  Another address can be ``0x02``.

Configuration variables (SPI):
------------------------------

Use this if you want to use your AS3935 in SPI mode.

.. code-block:: yaml

    # Example configuration for SPI (decide for one!)
    as3935_spi:
      cs_pin: GPIO12
      irq_pin: GPIO13
    # Example lightning and energy sensor
    sensor:
      - platform: as3935
        lightning_energy:
          name: "Lightning Energy"
        distance:
          name: "Distance Storm"
    binary_sensor:
      - platform: as3935
        name: "Storm Alert"

- **cs_pin** (*Required*, :ref:`Pin Schema <config-pin_schema>`): The chip select pin.

See Also
--------

- :ref:`sensor-filters`
- :apiref:`as3935/as3935.h`
- `AliExpress <https://de.aliexpress.com/af/as3935.html?SearchText=as3935>`__
- `Data Sheet <https://www.embeddedadventures.com/datasheets/AS3935_Datasheet_EN_v2.pdf>`__
- `Little Arduino Projects <https://github.com/tardate/LittleArduinoProjects/tree/master/playground/AS3935>`__
- `AMS AS3935 <https://ams.com/as3935>`__
- `SparkFun Library <https://github.com/sparkfun/SparkFun_AS3935_Lightning_Detector_Arduino_Library>`__
- :ghedit:`Edit`
