Returns the current state of the client. If a connection attempt fails, this can be used to get more information about the failure. All of the values have corresponding constants defined in …

Apr 21, 2023 · On ESP32, I have code for which Wi-Fi and MQTT are working perfectly reliably in one task, but in another task the m_mqttClient.connect(…) call hangs until MQTT_SOCKET_TIMEOUT, …

109// Note: the header is built at the end of the first MQTT_MAX_HEADER_SIZE bytes, so will start 110// (MQTT_MAX_HEADER_SIZE - <returned size>) bytes into the buffer

Dec 2, 2024 · Why does my ESP8266 MQTT client block the rest of the code while attempting to connect, causing a delay? I'm using the following code to connect to an MQTT broker on my ESP8266:

May 26, 2025 · The PubSubClient class provides multiple constructor overloads to accommodate different initialization patterns. All constructors initialize the client state to MQTT_DISCONNECTED …

This guide shows how to use the ESP32 with the PubSubClient library to connect to an MQTT broker, publish sensor data, and subscribe to topics. PubSubClient is a lightweight MQTT client for Arduino …

Discover tutorials, guides, and technical documentation for Arduino PubSubClient library to enhance your projects.

See the 'mqtt_reconnect_nonblocking' example for how to achieve the same result without blocking the main loop.

Jan 1, 2021 · Obviously there is a problem but beyond that who knows? All you have said is that this is an ESP8266 and you get getting an MQTT connection error. Please add some additional details.

A client library for the Arduino Ethernet Shield that provides support for MQTT. - pubsubclient/src/PubSubClient.cpp at master · knolleary/pubsubclient

It connects to an MQTT server then: - publishes "hello world" to the topic "outTopic" - subscribes to the topic "inTopic", printing out any messages it receives.