GPIO Switch
===========

.. seo::
    :description: Instructions for setting up GPIO pin switches in ESPHome that control GPIO outputs.
    :image: pin.svg

The ``gpio`` switch platform allows you to use any pin on your node as a
switch. You can for example hook up a relay to a GPIO pin and use it
through this platform.

.. figure:: images/gpio-ui.png
    :align: center
    :width: 80.0%

.. code-block:: yaml

    # Example configuration entry
    switch:
      - platform: gpio
        pin: GPIOXX
        name: "Living Room Dehumidifier"

Configuration variables:
------------------------

- **pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The
  GPIO pin to use for the switch.
- **interlock** (*Optional*, list): A list of other GPIO switches in an interlock group. See
  :ref:`switch-gpio-interlocking`.
- **interlock_wait_time** (*Optional*, :ref:`config-time`): For interlocking mode, set how long
  to wait after other items in an interlock group have been disabled before re-activating.
  Useful for motors where immediately turning on in the other direction could cause problems.

- All other options from :ref:`Switch <config-switch>`.

Active Low Switch
-----------------

To create an active-low switch (one that is turned off by default), use the :ref:`Pin Schema <config-pin_schema>`:

.. code-block:: yaml

    # Example configuration entry
    switch:
      - platform: gpio
        pin:
          number: GPIOXX
          inverted: true

Momentary Switch
----------------

To create momentary switches, for example switches that toggle a pin for a moment, you can use
`on_turn_on` trigger.

An example that uses a single relay to activate a remote control button. The button can only
start or stop the motor of the gate. In itself, the button or remote can not know if it opens
or closes the gate. The relay simulates the button press for 500ms.

.. code-block:: yaml

    # Example configuration entry
    switch:
      - platform: gpio
        pin: GPIOXX
        id: relay
        name: "Gate Remote"
        icon: "mdi:gate"
        on_turn_on:
        - delay: 500ms
        - switch.turn_off: relay

.. figure:: images/gate-remote-ui.png
    :align: center

.. _switch-gpio-interlocking:

Interlocking
------------

In some cases it is necessary to ensure that two outputs are never active at the same time.
ESPHome has a feature to prevent two GPIO Switches from being active at the same time called
interlocking. Just give *each switch* in the "interlocking group" an ``interlock`` option
with a list of all the switches in the group.

.. code-block:: yaml

    # Example configuration entry
    # Prevent relay #1 and relay #2 from being activated at the same time.
    switch:
      - platform: gpio
        pin: GPIOXX
        name: "Relay #1"
        id: relay1
        interlock: [relay2]

      - platform: gpio
        pin: GPIOXX
        name: "Relay #2"
        id: relay2
        interlock: [relay1]

Or with some YAML anchors you can further simplify the config:

.. code-block:: yaml

    # Example configuration entry
    switch:
      - platform: gpio
        # etc
        id: relay1
        interlock: &interlock_group [relay1, relay2]
      - platform: gpio
        # etc
        id: relay2
        interlock: *interlock_group

.. warning::

    These are software interlocks. As such, a software bug (which can *always* happen) can still
    activate both switches at the same time. Similarly, at reset time (before any of ESPHome's code runs)
    the relay GPIO pins may have pull-ups active, so the relay may be active before ESPHome can manually
    deactivate them.

    So it is **highly** recommended to use hardware interlocks (like SPDT-type relays) that ensure
    that two GPIOs are never active at the same time.

See also ``interlock_wait_time`` to make interlocks group wait some amount of time before activating
a switch.

See Also
--------

- :doc:`index`
- :doc:`/components/output/gpio`
- :doc:`/components/cover/template`
- :doc:`/cookbook/garage-door`
- :apiref:`gpio/switch/gpio_switch.h`
- :ghedit:`Edit`