esphome-docs/components/servo.rst
2019-11-02 21:00:09 +01:00

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Servo Component
===============
.. seo::
:description: Instructions for setting up servos in ESPHome
:image: servo.png
The ``servo`` component allows you to use servo motors with ESPHome. Servos are
motor controllers that contain all the electronics necessary for driving the motor and provide
a simple PWM interface to control the motor.
This integration works with both continuous-rotation and absolute servos and has a similar
interface to the Arduino Servo library.
First, create an :ref:`output component <output>` (here ``esp8266_pwm``) for the pin the
servo is connected to. Then connect that output to the servo component by assigning an ID.
Please note the frequency of the output must be around 50Hz, as most servo controllers
only operate in this frequency range.
.. note::
This component will not show up in the Home Assistant front-end automatically because
Home Assistant doesn't have support for servos. Please see :ref:`servo-ha-config`.
.. code-block:: yaml
# Example configuration entry
servo:
- id: my_servo
output: pwm_output
# Example output platform
# On ESP32, use ledc output
output:
- platform: esp8266_pwm
id: pwm_output
pin: D1
frequency: 50 Hz
Configuration variables:
------------------------
- **output** (**Required**, :ref:`config-id`): The ID of the :doc:`output component </components/output/index>`
to use for this servo.
- **id** (**Required**, :ref:`config-id`): The ID of this servo so that it can be controlled.
Advanced Options:
- **min_level** (*Optional*, percentage): The PWM duty cycle the minimum value (-100%) will map
to. Defaults to ``3%``.
- **idle_level** (*Optional*, percentage): The PWM duty cycle the idle value (0%) will map
to. This is also the state of the servo at startup. Defaults to ``7.5%``.
- **max_level** (*Optional*, percentage): The PWM duty cycle the maximum value (100%) will map
to. Defaults to ``12.0%``.
- **restore** (*Optional*, boolean): Whether to restore the state of the servo motor at startup.
This is useful if you have an absolute servo motor and it goes back to its 0 position at startup.
Defaults to ``false``.
.. note::
Some servos support a larger range for the level. For continuous rotation servos
this can speed them up a bit and for absolute servos this can extend their angle range.
You can configure the ``min_level`` and ``max_level`` options to adjust the level range
to match your servo (Experiment with these values).
.. _servo-write_action:
``servo.write`` Action
----------------------
To use your servo motor in :ref:`automations <automation>` or templates, you can use this action to set the
target level of the servo from -100% to 100%.
- -100% (= -1.0) is the minimum value of the servo. For continuous-rotation servos this will
rotate the servo backward.
- 0% (= 0.0) is the idle level of the servo. For continuous-rotation servos this will
stop the servo.
- 100% (= 1.0) is the maximum value of the servo. For continuous-rotation servos this will
rotate the servo forward.
.. code-block:: yaml
on_...:
then:
- servo.write:
id: my_servo
level: -100.0%
# Templated
- servo.write:
id: my_servo
# For template values, range is [-1; 1]
level: !lambda |-
if (id(my_binary_sensor).state) {
return 1.0;
} else {
return -1.0;
}
Configuration options:
- **id** (**Required**, :ref:`config-id`): The ID of the servo.
- **level** (*Optional*, percentage, :ref:`templatable <config-templatable>`): The target level.
Range is from -100% to 100% (-1.0 to 1.0).
.. note::
This action can also be expressed as a :ref:`lambda <config-lambda>`:
.. code-block:: cpp
id(my_servo).write(1.0);
.. _servo-detach_action:
``servo.detach`` Action
-----------------------
This :ref:`Action <config-action>` allows you to disable the output on a servo motor -
this will make the servo motor stop immediately and disable its active control.
.. code-block:: yaml
on_...:
then:
- servo.detach: my_servo
.. note::
This action can also be expressed as a :ref:`lambda <config-lambda>`:
.. code-block:: cpp
id(my_servo).detach();
.. _servo-ha-config:
Home Assistant Configuration
----------------------------
This component will not show up in the Home Assistant frontend automatically because Home Assistant
does not support servos natively (raise this issue in Home Assistant forums to make this a
higher priority for Home Assistant). You can add this to your Home Assistant configuration to
be able to control the servo from the frontend.
.. code-block:: yaml
# Home Assistant configuration
input_number:
servo_control:
name: Servo Control
initial: 0
min: -100
max: 100
step: 1
mode: slider
automation:
- alias: Write Servo Value to ESP
trigger:
platform: state
entity_id: input_number.servo_control
action:
# Replace livingroom with the name you gave the ESP
- service: esphome.livingroom_control_servo
data_template:
level: '{{ trigger.to_state.state | int }}'
.. code-block:: yaml
# ESPHome configuration
api:
services:
- service: control_servo
variables:
level: float
then:
- servo.write:
id: my_servo
level: !lambda 'return level / 100.0;'
servo:
- platform: ...
# [...] servo config
id: my_servo
See Also
--------
- :apiref:`servo/servo.h`
- :ghedit:`Edit`