This integration uses `sigma-delta modulation <https://en.wikipedia.org/wiki/Delta-sigma_modulation>`__
to output a floating-point value on a binary output. Unlike with :doc:`/components/output/slow_pwm`,
it is possible to update the output value with each update cycle, not just at the end of a longer period.
..figure:: images/sigma-delta-example.png
:align:center
:width:65.0%
Comparison between a *Slow PWM* with a period of 100s and a *sigma-delta output* with an update interval of 1s
For example, if you choose to toggle the output at most once every 1 second and decide on a
PWM period of 10 seconds, for reasonably frequent updates, with :doc:`/components/output/slow_pwm`
there are only 10 possible levels, and for higher precision a longer update interval is needed,
restricting the update rate.
A *sigma-delta* output is updated during each cycle, thus a higher precision can be achieved, without
being constrained by a calculation timeframe (=period).
So instead of having to define a ``period`` where the width of the pulse determines the output level, here you
choose an ``update_interval`` which acts like a clock signal from where the pulse density determines the output level.
This component can be used as a drop-in replacement for :doc:`/components/output/slow_pwm` by changing the ``platform`` to
``sigma_delta_output`` and changing ``period`` to ``update_interval`` (you usually want to set the *sigma-delta*'s
``update_interval`` as a fraction of *Slow PWM*'s ``period`` for similar results)
..code-block:: yaml
# Example configuration entry
output:
- platform: sigma_delta_output
update_interval: 10s
id: sd_heater_output
# Output to a pin
pin: 15
# Use the same output, but through automations
turn_on_action:
then:
- output.turn_on: heater_relay
turn_off_action:
then:
- output.turn_off: heater_relay
- platform: gpio
pin: 15
id: heater_relay
Configuration variables:
-**update_interval** (**Required**, :ref:`Time <config-time>`): The cycle interval at which the output is recalculated.
-**pin** (*Optional*, :ref:`Pin Schema <config-pin_schema>`): The pin to pulse.
-**state_change_action** (*Optional*, :ref:`Automation <automation>`): An automation to perform when the load is switched. If a lambda is used the boolean ``state`` parameter holds the new status.
-**turn_on_action** (*Optional*, :ref:`Automation <automation>`): An automation to perform when the load is turned on. Can be used to control for example a switch or output component.
-**turn_off_action** (*Optional*, :ref:`Automation <automation>`): An automation to perform when the load is turned off. ``turn_on_action`` and ``turn_off_action`` must be configured together.
- All options from :ref:`Output <config-output>`.
..note::
- If ``pin`` is defined, the GPIO pin state is writen before any action is executed.
-``state_change_action`` and ``turn_on_action``/``turn_off_action`` can be used togther. ``state_change_action`` is called before ``turn_on_action``/``turn_off_action``. It's recommended to use either ``state_change_action`` or ``turn_on_action``/``turn_off_action`` to change the state of an output. Using both automations together is only recommended for monitoring.
..note::
If the output must not be active for more than some fixed time before it has
to be off for a while to e.g. cool down, :doc:`/components/output/slow_pwm`
should be used with a ``max_power`` setting to better control the duty
