PubSubClient Class Reference

This class provides a client for doing simple publish and subscribe messaging with a server that supports MQTT. More...

#include <PubSubClient.h>

Inheritance diagram for PubSubClient:

Public Member Functions
	PubSubClient ()
	Creates an uninitialised client instance.
	PubSubClient (Client &client)
	Creates a partially initialised client instance.
	PubSubClient (IPAddress addr, uint16_t port, Client &client)
	Creates a fully configured client instance.
	PubSubClient (IPAddress addr, uint16_t port, Client &client, Stream &stream)
	Creates a fully configured client instance.
	PubSubClient (IPAddress addr, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client &client)
	Creates a fully configured client instance.
	PubSubClient (IPAddress addr, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client &client, Stream &stream)
	Creates a fully configured client instance.
	PubSubClient (uint8_t *ip, uint16_t port, Client &client)
	Creates a fully configured client instance.
	PubSubClient (uint8_t *ip, uint16_t port, Client &client, Stream &stream)
	Creates a fully configured client instance.
	PubSubClient (uint8_t *ip, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client &client)
	Creates a fully configured client instance.
	PubSubClient (uint8_t *ip, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client &client, Stream &stream)
	Creates a fully configured client instance.
	PubSubClient (const char *domain, uint16_t port, Client &client)
	Creates a fully configured client instance.
	PubSubClient (const char *domain, uint16_t port, Client &client, Stream &stream)
	Creates a fully configured client instance.
	PubSubClient (const char *domain, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client &client)
	Creates a fully configured client instance.
	PubSubClient (const char *domain, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client &client, Stream &stream)
	Creates a fully configured client instance.
	~PubSubClient ()
	Destructor for the PubSubClient class.
PubSubClient &	setServer (IPAddress ip, uint16_t port)
	Sets the server details.
PubSubClient &	setServer (uint8_t *ip, uint16_t port)
	Sets the server details.
PubSubClient &	setServer (const char *domain, uint16_t port)
	Sets the server details.
PubSubClient &	setCallback (MQTT_CALLBACK_SIGNATURE)
	Sets the message callback function.
PubSubClient &	setClient (Client &client)
	Sets the network client instance to use.
PubSubClient &	setStream (Stream &stream)
	Sets the stream to write received messages to.
PubSubClient &	setKeepAlive (uint16_t keepAlive)
	Sets the keep alive interval used by the client. This value should only be changed when the client is not connected. Set keepAlive to zero (0) to turn off the keep alive mechanism.
PubSubClient &	setSocketTimeout (uint16_t timeout)
	Sets the socket timeout used by the client. This determines how long the client will wait for incoming data when it expects data to arrive - for example, whilst it is in the middle of reading a MQTT packet.
bool	setBufferSize (size_t size)
	Sets the size, in bytes, of the internal send and receive buffer. This must be large enough to contain the full MQTT packet. When sending or receiving messages, the packet will contain the full topic string, the payload data, and a small number of header bytes.
size_t	getBufferSize ()
	Gets the current size of the internal buffer.
bool	connect (const char *id)
	Connects the client using a clean session without username and password.
bool	connect (const char *id, const char *user, const char *pass)
	Connects the client using a clean session with username and password.
bool	connect (const char *id, const char *willTopic, uint8_t willQos, bool willRetain, const char *willMessage)
	Connects the client using a clean session and will.
bool	connect (const char *id, const char *user, const char *pass, const char *willTopic, uint8_t willQos, bool willRetain, const char *willMessage)
	Connects the client using a clean session with username, password and will.
bool	connect (const char *id, const char *user, const char *pass, const char *willTopic, uint8_t willQos, bool willRetain, const char *willMessage, bool cleanSession)
	Connects the client with all possible parameters (user, password, will and session).
void	disconnect ()
	Disconnects the client.
bool	publish (const char *topic, const char *payload)
	Publishes a non retained message to the specified topic using QoS 0.
bool	publish (const char *topic, const char *payload, bool retained)
	Publishes a message to the specified topic using QoS 0.
bool	publish (const char *topic, const char *payload, uint8_t qos, bool retained)
	Publishes a message to the specified topic.
bool	publish (const __FlashStringHelper *topic, const char *payload, uint8_t qos, bool retained)
	Publishes a message to the specified topic.
bool	publish (const __FlashStringHelper *topic, const __FlashStringHelper *payload, uint8_t qos, bool retained)
	Publishes a message from __FlashStringHelper to the specified topic from __FlashStringHelper.
bool	publish (const char *topic, const uint8_t *payload, size_t plength)
	Publishes a non retained message to the specified topic using QoS 0.
bool	publish (const char *topic, const uint8_t *payload, size_t plength, bool retained)
	Publishes a message to the specified topic using QoS 0.
bool	publish (const char *topic, const uint8_t *payload, size_t plength, uint8_t qos, bool retained)
	Publishes a message to the specified topic.
bool	publish (const __FlashStringHelper *topic, const uint8_t *payload, size_t plength, uint8_t qos, bool retained)
	Publishes a message to the specified topic.
bool	publish_P (const char *topic, PGM_P payload, bool retained)
	Publishes a message stored in PROGMEM to the specified topic using QoS 0.
bool	publish_P (const char *topic, PGM_P payload, uint8_t qos, bool retained)
	Publishes a message stored in PROGMEM to the specified topic.
bool	publish_P (const __FlashStringHelper *topic, PGM_P payload, uint8_t qos, bool retained)
	Publishes a message stored in PROGMEM to the specified topic.
bool	publish_P (const char *topic, const uint8_t *payload, size_t plength, bool retained)
	Publishes a message stored in PROGMEM to the specified topic using QoS 0.
bool	publish_P (const char *topic, const uint8_t *payload, size_t plength, uint8_t qos, bool retained)
	Publishes a message stored in PROGMEM to the specified topic.
bool	publish_P (const __FlashStringHelper *topic, const uint8_t *payload, size_t plength, uint8_t qos, bool retained)
	Publishes a message stored in PROGMEM to the specified topic.
bool	beginPublish (const char *topic, size_t plength, bool retained)
	Start to publish a message using QoS 0. This API: beginPublish(...) one or more calls to write(...) endPublish() Allows for arbitrarily large payloads to be sent without them having to be copied into a new buffer and held in memory at one time.
bool	beginPublish (const char *topic, size_t plength, uint8_t qos, bool retained)
	Start to publish a message. This API: beginPublish(...) one or more calls to write(...) endPublish() Allows for arbitrarily large payloads to be sent without them having to be copied into a new buffer and held in memory at one time.
bool	beginPublish (const __FlashStringHelper *topic, size_t plength, uint8_t qos, bool retained)
	Start to publish a message using a topic from __FlashStringHelper F(). This API: beginPublish(...) one or more calls to write(...) endPublish() Allows for arbitrarily large payloads to be sent without them having to be copied into a new buffer and held in memory at one time.
bool	beginPublish_P (PGM_P topic, size_t plength, uint8_t qos, bool retained)
	Start to publish a message using a topic in PROGMEM. This API: beginPublish_P(...) one or more calls to write(...) endPublish() Allows for arbitrarily large payloads to be sent without them having to be copied into a new buffer and held in memory at one time.
bool	endPublish ()
	Finish sending a message that was started with a call to beginPublish.
virtual size_t	write (uint8_t data)
	Writes a single byte as a component of a publish started with a call to beginPublish. For performance reasons, this will be appended to the internal buffer, which will be flushed when full or on a call to endPublish().
virtual size_t	write (const uint8_t *buf, size_t size)
	Writes an array of bytes as a component of a publish started with a call to beginPublish. For performance reasons, this will be appended to the internal buffer, which will be flushed when full or on a call to endPublish().
size_t	write_P (PGM_P string)
	Writes a string in PROGMEM as a component of a publish started with a call to beginPublish. For performance reasons, this will be appended to the internal buffer, which will be flushed when full or on a call to endPublish().
size_t	write_P (const uint8_t *buf, size_t size)
	Writes an array of progmem bytes as a component of a publish started with a call to beginPublish. For performance reasons, this will be appended to the internal buffer, which will be flushed when full or on a call to endPublish().
bool	subscribe (const char *topic)
	Subscribes to messages published to the specified topic using QoS 0.
bool	subscribe (const __FlashStringHelper *topic)
	Subscribes to messages published to the specified topic from __FlashStringHelper using QoS 0.
bool	subscribe_P (PGM_P topic)
	Subscribes to messages published to the specified topic in PROGMEM using QoS 0.
bool	subscribe (const char *topic, uint8_t qos)
	Subscribes to messages published to the specified topic.
bool	subscribe (const __FlashStringHelper *topic, uint8_t qos)
	Subscribes to messages published to the specified topic from __FlashStringHelper.
bool	subscribe_P (PGM_P topic, uint8_t qos)
	Subscribes to messages published to the specified topic in PROGMEM.
bool	unsubscribe (const char *topic)
	Unsubscribes from the specified topic.
bool	unsubscribe (const __FlashStringHelper *topic)
	Unsubscribes from the specified topic from __FlashStringHelper.
bool	unsubscribe_P (PGM_P topic)
	Unsubscribes from the specified topic in PROGMEM.
bool	loop ()
	This should be called regularly to allow the client to process incoming messages and maintain its connection to the server.
bool	connected ()
	Checks whether the client is connected to the server.
int	state ()
	Returns the current state of the client. If a connection attempt fails, this can be used to get more information about the failure.

Detailed Description

This class provides a client for doing simple publish and subscribe messaging with a server that supports MQTT.

Definition at line 180 of file PubSubClient.h.

Constructor & Destructor Documentation

PubSubClient() [1/14]

PubSubClient::PubSubClient

(

)

Creates an uninitialised client instance.

Note

Before it can be used, it must be configured using the property setters setClient() and setServer().

Definition at line 43 of file PubSubClient.cpp.

PubSubClient() [2/14]

PubSubClient::PubSubClient

(

Client &

client

)

Creates a partially initialised client instance.

Parameters

client

The network client to use, for example WiFiClient.

Note

Before it can be used, it must be configured with the property setter setServer().

Definition at line 49 of file PubSubClient.cpp.

PubSubClient() [3/14]

PubSubClient::PubSubClient	(	IPAddress	addr,
		uint16_t	port,
		Client &	client )

Creates a fully configured client instance.

Parameters

addr	The address of the server.
port	The port to connect to.
client	The network client to use, for example WiFiClient.

Definition at line 53 of file PubSubClient.cpp.

PubSubClient() [4/14]

PubSubClient::PubSubClient	(	IPAddress	addr,
		uint16_t	port,
		Client &	client,
		Stream &	stream )

Creates a fully configured client instance.

Parameters

addr	The address of the server.
port	The port to connect to.
client	The network client to use, for example WiFiClient.
stream	A stream to write received messages to.

Definition at line 58 of file PubSubClient.cpp.

PubSubClient() [5/14]

PubSubClient::PubSubClient	(	IPAddress	addr,
		uint16_t	port,
		MQTT_CALLBACK_SIGNATURE	,
		Client &	client )

Creates a fully configured client instance.

Parameters

addr	The address of the server.
port	The port to connect to.
callback	Pointer to a message callback function. Called when a message arrives for a subscription created by this client.
client	The network client to use, for example WiFiClient.

Definition at line 64 of file PubSubClient.cpp.

PubSubClient() [6/14]

PubSubClient::PubSubClient	(	IPAddress	addr,
		uint16_t	port,
		MQTT_CALLBACK_SIGNATURE	,
		Client &	client,
		Stream &	stream )

Creates a fully configured client instance.

Parameters

addr	The address of the server.
port	The port to connect to.
callback	Pointer to a message callback function. Called when a message arrives for a subscription created by this client.
client	The network client to use, for example WiFiClient.
stream	A stream to write received messages to.

Definition at line 70 of file PubSubClient.cpp.

PubSubClient() [7/14]

PubSubClient::PubSubClient	(	uint8_t *	ip,
		uint16_t	port,
		Client &	client )

Creates a fully configured client instance.

Parameters

ip	The address of the server.
port	The port to connect to.
client	The network client to use, for example WiFiClient.

Definition at line 77 of file PubSubClient.cpp.

PubSubClient() [8/14]

PubSubClient::PubSubClient	(	uint8_t *	ip,
		uint16_t	port,
		Client &	client,
		Stream &	stream )

Creates a fully configured client instance.

Parameters

ip	The address of the server.
port	The port to connect to.
client	The network client to use, for example WiFiClient.
stream	A stream to write received messages to.

Definition at line 82 of file PubSubClient.cpp.

PubSubClient() [9/14]

PubSubClient::PubSubClient	(	uint8_t *	ip,
		uint16_t	port,
		MQTT_CALLBACK_SIGNATURE	,
		Client &	client )

Creates a fully configured client instance.

Parameters

ip	The address of the server.
port	The port to connect to.
callback	Pointer to a message callback function. Called when a message arrives for a subscription created by this client.
client	The network client to use, for example WiFiClient.

Definition at line 88 of file PubSubClient.cpp.

PubSubClient() [10/14]

PubSubClient::PubSubClient	(	uint8_t *	ip,
		uint16_t	port,
		MQTT_CALLBACK_SIGNATURE	,
		Client &	client,
		Stream &	stream )

Creates a fully configured client instance.

Parameters

ip	The address of the server.
port	The port to connect to.
callback	Pointer to a message callback function. Called when a message arrives for a subscription created by this client.
client	The network client to use, for example WiFiClient.
stream	A stream to write received messages to.

Definition at line 94 of file PubSubClient.cpp.

PubSubClient() [11/14]

PubSubClient::PubSubClient	(	const char *	domain,
		uint16_t	port,
		Client &	client )

Creates a fully configured client instance.

Parameters

domain	The address of the server.
port	The port to connect to.
client	The network client to use, for example WiFiClient.

Definition at line 101 of file PubSubClient.cpp.

PubSubClient() [12/14]

PubSubClient::PubSubClient	(	const char *	domain,
		uint16_t	port,
		Client &	client,
		Stream &	stream )

Creates a fully configured client instance.

Parameters

domain	The address of the server.
port	The port to connect to.
client	The network client to use, for example WiFiClient.
stream	A stream to write received messages to.

Definition at line 106 of file PubSubClient.cpp.

PubSubClient() [13/14]

PubSubClient::PubSubClient	(	const char *	domain,
		uint16_t	port,
		MQTT_CALLBACK_SIGNATURE	,
		Client &	client )

Creates a fully configured client instance.

Parameters

domain	The address of the server.
port	The port to connect to.
callback	Pointer to a message callback function. Called when a message arrives for a subscription created by this client.
client	The network client to use, for example WiFiClient.

Definition at line 112 of file PubSubClient.cpp.

PubSubClient() [14/14]

PubSubClient::PubSubClient	(	const char *	domain,
		uint16_t	port,
		MQTT_CALLBACK_SIGNATURE	,
		Client &	client,
		Stream &	stream )

Creates a fully configured client instance.

Parameters

domain	The address of the server.
port	The port to connect to.
callback	Pointer to a message callback function. Called when a message arrives for a subscription created by this client.
client	The network client to use, for example WiFiClient.
stream	A stream to write received messages to.

Definition at line 118 of file PubSubClient.cpp.

~PubSubClient()

PubSubClient::~PubSubClient

(

)

Destructor for the PubSubClient class.

Definition at line 125 of file PubSubClient.cpp.

Member Function Documentation

beginPublish() [1/3]

bool PubSubClient::beginPublish ( const __FlashStringHelper * topic, size_t plength, uint8_t qos, bool retained )

inline

Start to publish a message using a topic from __FlashStringHelper F(). This API: beginPublish(...) one or more calls to write(...) endPublish() Allows for arbitrarily large payloads to be sent without them having to be copied into a new buffer and held in memory at one time.

Parameters

topic	The topic from __FlashStringHelper to publish to.
plength	The length of the payload.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 759 of file PubSubClient.h.

beginPublish() [2/3]

bool PubSubClient::beginPublish ( const char * topic, size_t plength, bool retained )

inline

Start to publish a message using QoS 0. This API: beginPublish(...) one or more calls to write(...) endPublish() Allows for arbitrarily large payloads to be sent without them having to be copied into a new buffer and held in memory at one time.

Parameters

topic	The topic to publish to.
plength	The length of the payload.
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 721 of file PubSubClient.h.

beginPublish() [3/3]

bool PubSubClient::beginPublish ( const char * topic, size_t plength, uint8_t qos, bool retained )

inline

Start to publish a message. This API: beginPublish(...) one or more calls to write(...) endPublish() Allows for arbitrarily large payloads to be sent without them having to be copied into a new buffer and held in memory at one time.

Parameters

topic	The topic to publish to.
plength	The length of the payload.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 740 of file PubSubClient.h.

beginPublish_P()

bool PubSubClient::beginPublish_P ( PGM_P topic, size_t plength, uint8_t qos, bool retained )

inline

Start to publish a message using a topic in PROGMEM. This API: beginPublish_P(...) one or more calls to write(...) endPublish() Allows for arbitrarily large payloads to be sent without them having to be copied into a new buffer and held in memory at one time.

Parameters

topic	The topic in PROGMEM to publish to.
plength	The length of the payload.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 779 of file PubSubClient.h.

connect() [1/5]

bool PubSubClient::connect ( const char * id )

inline

Connects the client using a clean session without username and password.

Parameters

id	The client ID to use when connecting to the server.

Returns

true If client succeeded in establishing a connection to the broker. false If client failed to establish a connection to the broker.

Definition at line 444 of file PubSubClient.h.

connect() [2/5]

bool PubSubClient::connect ( const char * id, const char * user, const char * pass )

inline

Connects the client using a clean session with username and password.

Parameters

id	The client ID to use when connecting to the server.
user	The username to use.
pass	The password to use.

Note

If user is NULL, no username or password is used.

If pass is NULL, no password is used.

Returns

true If client succeeded in establishing a connection to the broker. false If client failed to establish a connection to the broker.

Definition at line 458 of file PubSubClient.h.

connect() [3/5]

bool PubSubClient::connect ( const char * id, const char * user, const char * pass, const char * willTopic, uint8_t willQos, bool willRetain, const char * willMessage )

inline

Connects the client using a clean session with username, password and will.

Parameters

id	The client ID to use when connecting to the server.
user	The username to use.
pass	The password to use.
willTopic	The topic to be used by the will message.
willQos	The quality of service to be used by the will message. [0, 1, 2].
willRetain	Publish the will message with the retain flag.
willMessage	The message to be used by the will message.

Note

If user is NULL, no username or password is used.

If pass is NULL, no password is used.

If willTopic is NULL, no will message is sent.

Returns

true If client succeeded in establishing a connection to the broker. false If client failed to establish a connection to the broker.

Definition at line 492 of file PubSubClient.h.

connect() [4/5]

bool PubSubClient::connect	(	const char *	id,
		const char *	user,
		const char *	pass,
		const char *	willTopic,
		uint8_t	willQos,
		bool	willRetain,
		const char *	willMessage,
		bool	cleanSession )

Connects the client with all possible parameters (user, password, will and session).

Parameters

id	The client ID to use when connecting to the server.
user	The username to use.
pass	The password to use.
willTopic	The topic to be used by the will message.
willQos	The quality of service to be used by the will message. [0, 1, 2].
willRetain	Publish the will message with the retain flag.
willMessage	The message to be used by the will message.
cleanSession	True to connect with a clean session.

Note

If user is NULL, no username or password is used.

If pass is NULL, no password is used.

If willTopic is NULL, no will message is sent.

Returns

true If client succeeded in establishing a connection to the broker. false If client failed to establish a connection to the broker.

Definition at line 130 of file PubSubClient.cpp.

connect() [5/5]

bool PubSubClient::connect ( const char * id, const char * willTopic, uint8_t willQos, bool willRetain, const char * willMessage )

inline

Connects the client using a clean session and will.

Parameters

id	The client ID to use when connecting to the server.
willTopic	The topic to be used by the will message.
willQos	The quality of service to be used by the will message. [0, 1, 2].
willRetain	Publish the will message with the retain flag.
willMessage	The message to be used by the will message.

Note

If willTopic is NULL, no will message is sent.

Returns

true If client succeeded in establishing a connection to the broker. false If client failed to establish a connection to the broker.

Definition at line 473 of file PubSubClient.h.

connected()

bool PubSubClient::connected

(

)

Checks whether the client is connected to the server.

Returns

true If the client is connected. false If the client is not connected.

Definition at line 235 of file PubSubClient.cpp.

disconnect()

void PubSubClient::disconnect

(

)

Disconnects the client.

Definition at line 250 of file PubSubClient.cpp.

endPublish()

bool PubSubClient::endPublish

(

)

Finish sending a message that was started with a call to beginPublish.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 631 of file PubSubClient.cpp.

getBufferSize()

size_t PubSubClient::getBufferSize

(

)

Gets the current size of the internal buffer.

Returns

The size of the internal buffer.

Definition at line 959 of file PubSubClient.cpp.

loop()

bool PubSubClient::loop

(

)

This should be called regularly to allow the client to process incoming messages and maintain its connection to the server.

Returns

true If the client is still connected. false If the client is no longer connected.

Definition at line 508 of file PubSubClient.cpp.

publish() [1/9]

bool PubSubClient::publish ( const __FlashStringHelper * topic, const __FlashStringHelper * payload, uint8_t qos, bool retained )

inline

Publishes a message from __FlashStringHelper to the specified topic from __FlashStringHelper.

Parameters

topic	The topic to publish to.
payload	The message to publish.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 579 of file PubSubClient.h.

publish() [2/9]

bool PubSubClient::publish ( const __FlashStringHelper * topic, const char * payload, uint8_t qos, bool retained )

inline

Publishes a message to the specified topic.

Parameters

topic	The topic from __FlashStringHelper to publish to.
payload	The message to publish.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 566 of file PubSubClient.h.

publish() [3/9]

bool PubSubClient::publish	(	const __FlashStringHelper *	topic,
		const uint8_t *	payload,
		size_t	plength,
		uint8_t	qos,
		bool	retained )

Publishes a message to the specified topic.

Parameters

topic	The topic from __FlashStringHelper to publish to.
payload	The message to publish.
plength	The length of the payload.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 563 of file PubSubClient.cpp.

publish() [4/9]

bool PubSubClient::publish ( const char * topic, const char * payload )

inline

Publishes a non retained message to the specified topic using QoS 0.

Parameters

topic	The topic to publish to.
payload	The message to publish.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 528 of file PubSubClient.h.

publish() [5/9]

bool PubSubClient::publish ( const char * topic, const char * payload, bool retained )

inline

Publishes a message to the specified topic using QoS 0.

Parameters

topic	The topic to publish to.
payload	The message to publish.
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 540 of file PubSubClient.h.

publish() [6/9]

bool PubSubClient::publish ( const char * topic, const char * payload, uint8_t qos, bool retained )

inline

Publishes a message to the specified topic.

Parameters

topic	The topic to publish to.
payload	The message to publish.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 553 of file PubSubClient.h.

publish() [7/9]

bool PubSubClient::publish ( const char * topic, const uint8_t * payload, size_t plength )

inline

Publishes a non retained message to the specified topic using QoS 0.

Parameters

topic	The topic to publish to.
payload	The message to publish.
plength	The length of the payload.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 591 of file PubSubClient.h.

publish() [8/9]

bool PubSubClient::publish ( const char * topic, const uint8_t * payload, size_t plength, bool retained )

inline

Publishes a message to the specified topic using QoS 0.

Parameters

topic	The topic to publish to.
payload	The message to publish.
plength	The length of the payload.
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 604 of file PubSubClient.h.

publish() [9/9]

bool PubSubClient::publish	(	const char *	topic,
		const uint8_t *	payload,
		size_t	plength,
		uint8_t	qos,
		bool	retained )

Publishes a message to the specified topic.

Parameters

topic	The topic to publish to.
payload	The message to publish.
plength	The length of the payload.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 555 of file PubSubClient.cpp.

publish_P() [1/6]

bool PubSubClient::publish_P	(	const __FlashStringHelper *	topic,
		const uint8_t *	payload,
		size_t	plength,
		uint8_t	qos,
		bool	retained )

Publishes a message stored in PROGMEM to the specified topic.

Parameters

topic	The topic from __FlashStringHelper to publish to.
payload	The message from PROGMEM to publish.
plength	The length of the payload.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 579 of file PubSubClient.cpp.

publish_P() [2/6]

bool PubSubClient::publish_P ( const __FlashStringHelper * topic, PGM_P payload, uint8_t qos, bool retained )

inline

Publishes a message stored in PROGMEM to the specified topic.

Parameters

topic	The topic from __FlashStringHelper to publish to.
payload	The message to publish.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 666 of file PubSubClient.h.

publish_P() [3/6]

bool PubSubClient::publish_P ( const char * topic, const uint8_t * payload, size_t plength, bool retained )

inline

Publishes a message stored in PROGMEM to the specified topic using QoS 0.

Parameters

topic	The topic to publish to.
payload	The message to publish.
plength	The length of the payload.
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 679 of file PubSubClient.h.

publish_P() [4/6]

bool PubSubClient::publish_P	(	const char *	topic,
		const uint8_t *	payload,
		size_t	plength,
		uint8_t	qos,
		bool	retained )

Publishes a message stored in PROGMEM to the specified topic.

Parameters

topic	The topic to publish to.
payload	The message to publish.
plength	The length of the payload.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 571 of file PubSubClient.cpp.

publish_P() [5/6]

bool PubSubClient::publish_P ( const char * topic, PGM_P payload, bool retained )

inline

Publishes a message stored in PROGMEM to the specified topic using QoS 0.

Parameters

topic	The topic to publish to.
payload	The message to publish.
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 640 of file PubSubClient.h.

publish_P() [6/6]

bool PubSubClient::publish_P ( const char * topic, PGM_P payload, uint8_t qos, bool retained )

inline

Publishes a message stored in PROGMEM to the specified topic.

Parameters

topic	The topic to publish to.
payload	The message to publish.
qos	The quality of service (QoS levels) to publish at. [0, 1, 2].
retained	Publish the message with the retain flag.

Returns

true If the publish succeeded. false If the publish failed, either connection lost or message too large.

Definition at line 653 of file PubSubClient.h.

setBufferSize()

bool PubSubClient::setBufferSize

(

size_t

size

)

Sets the size, in bytes, of the internal send and receive buffer. This must be large enough to contain the full MQTT packet. When sending or receiving messages, the packet will contain the full topic string, the payload data, and a small number of header bytes.

Parameters

size	The size, in bytes, for the internal buffer.

Returns

true If the buffer was resized. false If the buffer could not be resized.

Note

Changing the buffer size while the client is still connected may result in undefined behavior. It is recommended to change the buffer size only when the client is disconnected.

The buffer size must be at least #MQTT_MIN_BUFFER_SIZE bytes. Otherwise this function will return false and the buffer size will remain unchanged.

In case MQTT is not needed and to save memory, the buffer can be freed by setting the size to 0.

If not explicitly set/called, the buffer size will default to MQTT_MAX_PACKET_SIZE bytes.

Definition at line 937 of file PubSubClient.cpp.

setCallback()

PubSubClient & PubSubClient::setCallback

(

MQTT_CALLBACK_SIGNATURE

)

Sets the message callback function.

Parameters

callback

Pointer to a message callback function. Called when a message arrives for a subscription created by this client.

Returns

The client instance, allowing the function to be chained.

Definition at line 922 of file PubSubClient.cpp.

setClient()

PubSubClient & PubSubClient::setClient

(

Client &

client

)

Sets the network client instance to use.

Parameters

client

The network client to use, for example WiFiClient.

Returns

The client instance, allowing the function to be chained.

Definition at line 927 of file PubSubClient.cpp.

setKeepAlive()

PubSubClient & PubSubClient::setKeepAlive

(

uint16_t

keepAlive

)

Sets the keep alive interval used by the client. This value should only be changed when the client is not connected. Set keepAlive to zero (0) to turn off the keep alive mechanism.

Parameters

keepAlive

The keep alive interval, in seconds.

Returns

The client instance, allowing the function to be chained.

Definition at line 963 of file PubSubClient.cpp.

setServer() [1/3]

PubSubClient & PubSubClient::setServer	(	const char *	domain,
		uint16_t	port )

Sets the server details.

Parameters

domain	The address of the server.
port	The port to connect to.

Returns

The client instance, allowing the function to be chained.

Definition at line 905 of file PubSubClient.cpp.

setServer() [2/3]

PubSubClient & PubSubClient::setServer	(	IPAddress	ip,
		uint16_t	port )

Sets the server details.

Parameters

ip	The address of the server.
port	The port to connect to.

Returns

The client instance, allowing the function to be chained.

Definition at line 897 of file PubSubClient.cpp.

setServer() [3/3]

PubSubClient & PubSubClient::setServer	(	uint8_t *	ip,
		uint16_t	port )

Sets the server details.

Parameters

ip	The address of the server.
port	The port to connect to.

Returns

The client instance, allowing the function to be chained.

Definition at line 892 of file PubSubClient.cpp.

setSocketTimeout()

PubSubClient & PubSubClient::setSocketTimeout

(

uint16_t

timeout

)

Sets the socket timeout used by the client. This determines how long the client will wait for incoming data when it expects data to arrive - for example, whilst it is in the middle of reading a MQTT packet.

Parameters

timeout

The socket timeout, in seconds.

Returns

The client instance, allowing the function to be chained.

Definition at line 968 of file PubSubClient.cpp.

setStream()

PubSubClient & PubSubClient::setStream

(

Stream &

stream

)

Sets the stream to write received messages to.

Parameters

stream

A stream to write received messages to.

Returns

The client instance, allowing the function to be chained.

Definition at line 932 of file PubSubClient.cpp.

state()

int PubSubClient::state

(

)

Returns the current state of the client. If a connection attempt fails, this can be used to get more information about the failure.

Note

All of the values have corresponding constants defined in PubSubClient.h.

Returns

See state() result

Definition at line 973 of file PubSubClient.cpp.

subscribe() [1/4]

bool PubSubClient::subscribe ( const __FlashStringHelper * topic )

inline

Subscribes to messages published to the specified topic from __FlashStringHelper using QoS 0.

Parameters

topic

The topic from __FlashStringHelper to subscribe to.

Returns

true If sending the subscribe succeeded. false If sending the subscribe failed, either connection lost or message too large.

Definition at line 846 of file PubSubClient.h.

subscribe() [2/4]

bool PubSubClient::subscribe ( const __FlashStringHelper * topic, uint8_t qos )

inline

Subscribes to messages published to the specified topic from __FlashStringHelper.

Parameters

topic	The topic from __FlashStringHelper to subscribe to.
qos	The qos to subscribe at. [0, 1].

Returns

true If sending the subscribe succeeded. false If sending the subscribe failed, either connection lost or message too large.

Definition at line 879 of file PubSubClient.h.

subscribe() [3/4]

bool PubSubClient::subscribe ( const char * topic )

inline

Subscribes to messages published to the specified topic using QoS 0.

Parameters

topic

The topic to subscribe to.

Returns

true If sending the subscribe succeeded. false If sending the subscribe failed, either connection lost or message too large.

Definition at line 836 of file PubSubClient.h.

subscribe() [4/4]

bool PubSubClient::subscribe ( const char * topic, uint8_t qos )

inline

Subscribes to messages published to the specified topic.

Parameters

topic	The topic to subscribe to.
qos	The qos to subscribe at. [0, 1].

Returns

true If sending the subscribe succeeded. false If sending the subscribe failed, either connection lost or message too large.

Definition at line 868 of file PubSubClient.h.

subscribe_P() [1/2]

bool PubSubClient::subscribe_P ( PGM_P topic )

inline

Subscribes to messages published to the specified topic in PROGMEM using QoS 0.

Parameters

topic

The topic in PROGMEM to subscribe to.

Returns

true If sending the subscribe succeeded. false If sending the subscribe failed, either connection lost or message too large.

Definition at line 857 of file PubSubClient.h.

subscribe_P() [2/2]

bool PubSubClient::subscribe_P ( PGM_P topic, uint8_t qos )

inline

Subscribes to messages published to the specified topic in PROGMEM.

Parameters

topic	The topic in PROGMEM to subscribe to.
qos	The qos to subscribe at. [0, 1].

Returns

true If sending the subscribe succeeded. false If sending the subscribe failed, either connection lost or message too large.

Definition at line 891 of file PubSubClient.h.

unsubscribe() [1/2]

bool PubSubClient::unsubscribe ( const __FlashStringHelper * topic )

inline

Unsubscribes from the specified topic from __FlashStringHelper.

Parameters

topic

The topic from __FlashStringHelper to unsubscribe from.

Returns

true If sending the unsubscribe succeeded. false If sending the unsubscribe failed, either connection lost or message too large.

Definition at line 911 of file PubSubClient.h.

unsubscribe() [2/2]

bool PubSubClient::unsubscribe ( const char * topic )

inline

Unsubscribes from the specified topic.

Parameters

topic

The topic to unsubscribe from.

Returns

true If sending the unsubscribe succeeded. false If sending the unsubscribe failed, either connection lost or message too large.

Definition at line 901 of file PubSubClient.h.

unsubscribe_P()

bool PubSubClient::unsubscribe_P ( PGM_P topic )

inline

Unsubscribes from the specified topic in PROGMEM.

Parameters

topic

The topic in PROGMEM to unsubscribe from.

Returns

true If sending the unsubscribe succeeded. false If sending the unsubscribe failed, either connection lost or message too large.

Definition at line 922 of file PubSubClient.h.

write() [1/2]

size_t PubSubClient::write ( const uint8_t * buf, size_t size )

virtual

Writes an array of bytes as a component of a publish started with a call to beginPublish. For performance reasons, this will be appended to the internal buffer, which will be flushed when full or on a call to endPublish().

Parameters

buf	The bytes to write.
size	The length of the payload to be sent.

Returns

The number of bytes written. If return value is != size a write error occurred.

Definition at line 679 of file PubSubClient.cpp.

write() [2/2]

size_t PubSubClient::write ( uint8_t data )

virtual

Writes a single byte as a component of a publish started with a call to beginPublish. For performance reasons, this will be appended to the internal buffer, which will be flushed when full or on a call to endPublish().

Parameters

data	A byte to write to the publish payload.

Returns

The number of bytes written (0 or 1). If 0 is returned a write error occurred.

Definition at line 675 of file PubSubClient.cpp.

write_P() [1/2]

size_t PubSubClient::write_P	(	const uint8_t *	buf,
		size_t	size )

Writes an array of progmem bytes as a component of a publish started with a call to beginPublish. For performance reasons, this will be appended to the internal buffer, which will be flushed when full or on a call to endPublish().

Parameters

buf	The bytes to write.
size	The length of the payload to be sent.

Returns

The number of bytes written. If return value is != size a write error occurred.

Definition at line 686 of file PubSubClient.cpp.

write_P() [2/2]

size_t PubSubClient::write_P ( PGM_P string )

inline

Writes a string in PROGMEM as a component of a publish started with a call to beginPublish. For performance reasons, this will be appended to the internal buffer, which will be flushed when full or on a call to endPublish().

Parameters

string

The message to write.

Returns

The number of bytes written. If return value is != string length a write error occurred.

Definition at line 816 of file PubSubClient.h.

---

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

• src/PubSubClient.h
• src/PubSubClient.cpp