Questions tagged [mqtt]

MQTT (Message Queuing Telemetry Transport) is a machine-to-machine (M2M)/"Internet of Things" connectivity protocol. The MQTT protocol enables a publish/subscribe messaging model in an extremely lightweight way. It is useful for connections with remote locations where a small code footprint is required and/or network bandwidth is at a premium.

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Arduino Uno - MQTT message using PUBSUB on ESP8266

I'm trying to write code involving MQTT messages to operate an ESP8266 relay ( a Sonoff device ), using PubSub library. For some, unknown for me, reason - messages larger than 99 chars are not sent. ...
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ESP8266 fail to connect MQTT broker

I am using NodeMCU dev board with ESP8266 WIFI. Every time I try to connect to my local broker it returns this error: failed, rc=-2 try again in 5 seconds I am using Ubuntu 18.04, my local brokers ...
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Unable to Configure MQTT Client ID using Adafruit MQTT Library

I am utilizing the MQTT library that Adafruit has created, located here, and the library itself works wonderfully - however I am finding myself unable to edit the Client ID or configure the PINGRESP. ...
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String & Char concatenations

A newbie in Arduino- and I'm trying to concatenate string and chars ( well in python it is quite different ). I'm trying to post a MQTT message- constructed following format to the client.publish(...
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MQTT over serial

I'm planning to build a 32 relay IOT node next to my Raspberry Pi. The relays will be controlled by an Arduino Mega 2560. The Pi will run Home Assistant and Mosquitto so I would prefer to communicate ...
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MQTT bridging with Arduino and ESP8266 - What software should I use?

Sorry for the vagueness in my question, I am just looking for ideas to point me in the correct direction please... I wish to connect many (read: 20+) different sensors to a local wifi network and ...
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Soft WDT with HX711 and PubSubClient libraries

I'm using NodeMCU 0.9 My sketch crashes if the following 2 include are present in the sketch: #include <PubSubClient.h> #include <HX711.h> I obtain a Soft WDT reset If I do not use ...
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MQTT not working on ESP8266 (Nodemcu 0.9)

I'm trying to use NodeMCU on my ESP8266 (NodeMCU 0.9) but the board keep crashing and I don't understand why. I tested the mqtt broker using command line and it works perfectly, so I can suppose that ...
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ESP8266 MQTT client error

#include <PubSubClient.h> #include <ESP8266WiFi.h> //EDIT THESE LINES TO MATCH YOUR SETUP #define MQTT_SERVER "YOUR.MQTT.SERVER.IP" const char* ssid = "YOUR_SSID"; const char* password = "...
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Arduino MQTT Bluetooth

Is there a library to use MQTT with a bluetooth module (HC-06) instead of WiFi? If not is there a similar ready for use implementation of a publisher subscriber pattern available?

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