esphome-docs/components/switch/gpio.rst
2019-05-12 22:44:59 +02:00

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GPIO Switch
===========
.. seo::
:description: Instructions for setting up GPIO pin switches in ESPHome that control GPIO outputs.
:image: pin.png
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: 25
name: "Living Room Dehumidifier"
Configuration variables:
------------------------
- **pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The
GPIO pin to use for the switch.
- **name** (**Required**, string): The name for the switch.
- **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation.
- **restore_mode** (*Optional*): Control how the GPIO Switch attempts to restore state on bootup.
For restoring on ESP8266s, also see ``esp8266_restore_from_flash`` in the
:doc:`esphome section </components/esphome>`.
- ``RESTORE_DEFAULT_OFF`` (Default) - Attempt to restore state and default to OFF if not possible to restore.
- ``RESTORE_DEFAULT_ON`` - Attempt to restore state and default to ON.
- ``ALWAYS_OFF`` - Always initialize the pin as OFF on bootup.
- ``ALWAYS_ON`` - Always initialize the pin as ON on bootup.
- **interlock** (*Optional*, list): A list of other GPIO switches in an interlock group. See
:ref:`switch-gpio-interlocking`.
- 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: 25
inverted: yes
Momentary Switch
----------------
To create momentary switches, for example switches that toggle a pin for a moment, you can use
:doc:`template switches <template>`.
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: 25
id: relay
- platform: template
name: "Gate Remote"
icon: "mdi:gate"
turn_on_action:
- switch.turn_on: relay
- 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: GPIO25
name: "Relay #1"
id: relay1
interlock: [relay2]
- platform: gpio
pin: GPIO26
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
--------
- :doc:`index`
- :doc:`/components/output/gpio`
- :doc:`/components/cover/template`
- :doc:`/cookbook/garage-door`
- :apiref:`gpio/switch/gpio_switch.h`
- :ghedit:`Edit`