Base-class for all sensors. More...

#include <sensor.h>

Inheritance diagram for esphome::sensor::Sensor:

Data Structures
struct	SensorFlags

Public Member Functions
	Sensor ()

int8_t	get_accuracy_decimals ()
	Get the accuracy in decimals, using the manual override if set.

void	set_accuracy_decimals (int8_t accuracy_decimals)
	Manually set the accuracy in decimals.

bool	has_accuracy_decimals () const
	Check if the accuracy in decimals has been manually set.

StateClass	get_state_class ()
	Get the state class, using the manual override if set.

void	set_state_class (StateClass state_class)
	Manually set the state class.

bool	get_force_update () const
	Get whether force update mode is enabled.

void	set_force_update (bool force_update)
	Set force update mode.

void	add_filter (Filter *filter)
	Add a filter to the filter chain. Will be appended to the back.

void	add_filters (std::initializer_list< Filter * > filters)
	Add a list of vectors to the back of the filter chain.

void	set_filters (std::initializer_list< Filter * > filters)
	Clear the filters and replace them by filters.

void	clear_filters ()
	Clear the entire filter chain.

float	get_state () const
	Getter-syntax for .state.

float	get_raw_state () const
	Get the last state received by publish_state(), before any filters were applied.

void	publish_state (float state)
	Publish a new state to the front-end.

template<typename F >
void	add_on_state_callback (F &&callback)
	Add a callback that will be called every time a filtered value arrives.

template<typename F >
void	add_on_raw_state_callback (F &&callback)
	Add a callback that will be called every time the sensor sends a raw value.

void	internal_send_state_to_frontend (float state)

Public Member Functions inherited from esphome::EntityBase
	ESPDEPRECATED ("Use get_name_to() or get_log_name() instead. Will be removed in ESPHome 2027.5.0", "2026.11.0") const StringRef &get_name() const
	The name is in flash here; the first call makes a RAM copy that is kept for the life of the device.

StringRef	get_name_to (std::span< char, ENTITY_NAME_BUF_SIZE > buffer) const
	Get the name of this Entity, copied out of flash into buffer.

	ESPDEPRECATED ("Use get_name_to() or get_log_name() instead. Will be removed in ESPHome 2027.5.0", "2026.11.0") const StringRef &get_name() const

const StringRef &	get_name_to (std::span< char, ENTITY_NAME_BUF_SIZE >) const

bool	name_equals (const StringRef &other) const

const ProgmemStringRef &	get_name_progmem () const
	The name as stored, for consumers that read flash themselves (e.g. API progmem fields).

size_t	write_name_to (char *buf, size_t buf_size) const
	Copy the name into buf (null terminated), returns its length.

const LogString *	get_log_name () const
	Get the name for a "%s" log argument (LOG_STR_ARG).

bool	has_own_name () const

uint32_t	get_object_id_hash () const

StringRef	get_object_id_to (std::span< char, OBJECT_ID_MAX_LEN > buf) const
	Get object_id with zero heap allocation For static case: returns StringRef to internal storage (buffer unused) For dynamic case: formats into buffer and returns StringRef to buffer.

size_t	write_object_id_to (char *buf, size_t buf_size) const
	Write object_id directly to buffer, returns length written (excluding null) Useful for building compound strings without intermediate buffer.

bool	is_internal () const

void	set_internal (bool internal)

bool	is_disabled_by_default () const

EntityCategory	get_entity_category () const

const char *	get_device_class_to (std::span< char, MAX_DEVICE_CLASS_LENGTH > buffer) const

ProgmemStringRef	get_device_class_progmem () const
	The device class as stored (in flash on ESP8266), for consumers that read flash themselves.

StringRef	get_unit_of_measurement_ref () const

const char *	get_icon_to (std::span< char, MAX_ICON_LENGTH > buffer) const

ProgmemStringRef	get_icon_progmem () const
	The icon as stored (in flash on ESP8266), for consumers that read flash themselves.

uint32_t	get_device_id () const

Device *	get_device () const

bool	has_state () const

void	set_has_state (bool state)

	ESPDEPRECATED ("Use make_entity_preference<T>() instead, or preferences won't be migrated. " "See https://github.com/esphome/backlog/issues/85. Will be removed in 2027.1.0.", "2026.7.0") uint32_t get_preference_hash()
	Get a unique hash for storing preferences/settings for this entity.

template<typename T >
ESPPreferenceObject	make_entity_preference (uint32_t version=0)
	Create a preference object for storing this entity's state/settings.

template<typename T >
ESPPreferenceObject	make_entity_preference (uint32_t version, bool in_flash)
	As make_entity_preference(), stored in flash or RTC memory where the backend supports the choice.

Data Fields
float	state
	This member variable stores the last state that has passed through all filters.

Protected Attributes
float	raw_state_ {NAN}
	The last state passed to publish_state(), before filters.

LazyCallbackManager< void(float)>	raw_callback_
	Storage for raw state callbacks.

LazyCallbackManager< void(float)>	callback_
	Storage for filtered state callbacks.

Filter *	filter_list_ {nullptr}
	Store all active filters.

int8_t	accuracy_decimals_ {-1}
	Accuracy in decimals (-1 = not set)

StateClass	state_class_ {STATE_CLASS_NONE}
	State class (STATE_CLASS_NONE = not set)

struct esphome::sensor::Sensor::SensorFlags	sensor_flags_

Protected Attributes inherited from esphome::EntityBase
ProgmemStringRef	name_

uint32_t	object_id_hash_ {}

Device *	device_ {}

struct esphome::EntityBase::EntityFlags	flags_

uint8_t	device_class_idx_ {}

uint8_t	uom_idx_ {}

uint8_t	icon_idx_ {}

Additional Inherited Members
Protected Member Functions inherited from esphome::EntityBase
friend	void::setup ()

friend	void::original_setup ()

void	configure_entity_ (const char *name, uint32_t object_id_hash, uint32_t entity_fields)
	Combined entity setup from codegen: set name, object_id hash, entity string indices, and flags.

void	set_device_ (Device *device)

ESPPreferenceObject	make_entity_preference_ (size_t size, uint32_t version)
	Non-template helpers for make_entity_preference() to avoid code bloat.

ESPPreferenceObject	make_entity_preference_ (size_t size, uint32_t version, bool in_flash)

uint32_t	entity_preference_key_ (uint32_t version)
	Key for both helpers; preference hash migration goes here.

Detailed Description

Base-class for all sensors.

A sensor has unit of measurement and can use publish_state to send out a new value with the specified accuracy.

Definition at line 47 of file sensor.h.

Constructor & Destructor Documentation

◆ Sensor()

esphome::sensor::Sensor::Sensor ( )

explicit

Definition at line 43 of file sensor.cpp.

Member Function Documentation

◆ add_filter()

void esphome::sensor::Sensor::add_filter ( Filter * filter )

Add a filter to the filter chain. Will be appended to the back.

Definition at line 85 of file sensor.cpp.

◆ add_filters()

void esphome::sensor::Sensor::add_filters ( std::initializer_list< Filter * > filters )

Add a list of vectors to the back of the filter chain.

This may look like:

sensor->add_filters({ LambdaFilter([&](float value) -> optional<float> { return 42/value; }), OffsetFilter(1), SlidingWindowMovingAverageFilter(15, 15), // average over last 15 values });

Definition at line 99 of file sensor.cpp.

◆ add_on_raw_state_callback()

template<typename F >

void esphome::sensor::Sensor::add_on_raw_state_callback ( F && callback )

inline

Add a callback that will be called every time the sensor sends a raw value.

When USE_SENSOR_FILTER is not enabled, delegates to the regular callback since raw state equals filtered state without filter support compiled in.

Definition at line 125 of file sensor.h.

◆ add_on_state_callback()

template<typename F >

void esphome::sensor::Sensor::add_on_state_callback ( F && callback )

inline

Add a callback that will be called every time a filtered value arrives.

Definition at line 121 of file sensor.h.

◆ clear_filters()

void esphome::sensor::Sensor::clear_filters ( )

Clear the entire filter chain.

Definition at line 108 of file sensor.cpp.

◆ get_accuracy_decimals()

int8_t esphome::sensor::Sensor::get_accuracy_decimals ( )

Get the accuracy in decimals, using the manual override if set.

Definition at line 45 of file sensor.cpp.

◆ get_force_update()

bool esphome::sensor::Sensor::get_force_update ( ) const

inline

Get whether force update mode is enabled.

If the sensor is in force_update mode, the frontend is required to save all state changes to the database when they are published, even if the state is the same as before.

Definition at line 70 of file sensor.h.

◆ get_raw_state()

float esphome::sensor::Sensor::get_raw_state ( ) const

inline

Get the last state received by publish_state(), before any filters were applied.

Definition at line 100 of file sensor.h.

◆ get_state()

float esphome::sensor::Sensor::get_state ( ) const

inline

Getter-syntax for .state.

Definition at line 98 of file sensor.h.

◆ get_state_class()

StateClass esphome::sensor::Sensor::get_state_class ( )

Get the state class, using the manual override if set.

Definition at line 59 of file sensor.cpp.

◆ has_accuracy_decimals()

bool esphome::sensor::Sensor::has_accuracy_decimals ( ) const

inline

Check if the accuracy in decimals has been manually set.

Definition at line 56 of file sensor.h.

◆ internal_send_state_to_frontend()

void esphome::sensor::Sensor::internal_send_state_to_frontend ( float state )

Definition at line 116 of file sensor.cpp.

◆ publish_state()

void esphome::sensor::Sensor::publish_state ( float state )

Publish a new state to the front-end.

The value is passed through the filter chain (when filters are compiled in) before landing in the state member and triggering the state callback. The pre-filter value is available via get_raw_state().

Parameters

state The state as a floating point number.

Definition at line 65 of file sensor.cpp.

◆ set_accuracy_decimals()

void esphome::sensor::Sensor::set_accuracy_decimals ( int8_t accuracy_decimals )

Manually set the accuracy in decimals.

Definition at line 50 of file sensor.cpp.

◆ set_filters()

void esphome::sensor::Sensor::set_filters ( std::initializer_list< Filter * > filters )

Clear the filters and replace them by filters.

Definition at line 104 of file sensor.cpp.

◆ set_force_update()

void esphome::sensor::Sensor::set_force_update ( bool force_update )

inline

Set force update mode.

Definition at line 72 of file sensor.h.

◆ set_state_class()

void esphome::sensor::Sensor::set_state_class ( StateClass state_class )

Manually set the state class.

Definition at line 55 of file sensor.cpp.

Field Documentation

◆ accuracy_decimals_

int8_t esphome::sensor::Sensor::accuracy_decimals_ {-1}

protected

Accuracy in decimals (-1 = not set)

Definition at line 156 of file sensor.h.

◆ callback_

LazyCallbackManager<void(float)> esphome::sensor::Sensor::callback_

protected

Storage for filtered state callbacks.

Definition at line 149 of file sensor.h.

◆ filter_list_

Filter* esphome::sensor::Sensor::filter_list_ {nullptr}

protected

Store all active filters.

Definition at line 152 of file sensor.h.

◆ raw_callback_

LazyCallbackManager<void(float)> esphome::sensor::Sensor::raw_callback_

protected

Storage for raw state callbacks.

Definition at line 147 of file sensor.h.

◆ raw_state_

float esphome::sensor::Sensor::raw_state_ {NAN}

protected

The last state passed to publish_state(), before filters.

Definition at line 146 of file sensor.h.

◆ sensor_flags_

struct esphome::sensor::Sensor::SensorFlags esphome::sensor::Sensor::sensor_flags_

protected

◆ state

float esphome::sensor::Sensor::state

This member variable stores the last state that has passed through all filters.

On startup, when no state is available yet, this is NAN (not-a-number) and the validity can be checked using has_state().

This is exposed through a member variable for ease of use in esphome lambdas.

Definition at line 140 of file sensor.h.

◆ state_class_

StateClass esphome::sensor::Sensor::state_class_ {STATE_CLASS_NONE}

protected

State class (STATE_CLASS_NONE = not set)

Definition at line 157 of file sensor.h.

The documentation for this class was generated from the following files:

esphome/components/sensor/sensor.h
esphome/components/sensor/sensor.cpp

Data Structures

Public Member Functions

Data Fields

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Sensor()

Member Function Documentation

◆ add_filter()

◆ add_filters()

◆ add_on_raw_state_callback()

◆ add_on_state_callback()

◆ clear_filters()

◆ get_accuracy_decimals()

◆ get_force_update()

◆ get_raw_state()

◆ get_state()

◆ get_state_class()

◆ has_accuracy_decimals()

◆ internal_send_state_to_frontend()

◆ publish_state()

◆ set_accuracy_decimals()

◆ set_filters()

◆ set_force_update()

◆ set_state_class()

Field Documentation

◆ accuracy_decimals_

◆ callback_

◆ filter_list_

◆ raw_callback_

◆ raw_state_

◆ sensor_flags_

◆ state

◆ state_class_