Questions tagged [mqtt]

For questions concerning the MQTT messaging protocol, a lightweight TCP/IP-based system for machine-to-machine communication.

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7
votes
1answer
1k views

Are there standardized MQTT topics?

I am new to MQTT (and home automation in general, I am much more in the systems and dev side), flashed a WiFi switch (Sonoff Basic), connected it to an instance of Mosquitto and Home Assistant and so ...
4
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1answer
59 views

Eclipse solutions without a gateway

I'm currently reading the Eclipse IoT documents for a big scale company. Knowing that having a Raspberry as a Gateway means more costs, do you guys think that Eclipse solutions for a MQTT connection ...
6
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3answers
505 views

MQTT Connection Using Keep-Alive > 5 Minutes Silently Disconnects on Azure VM Broker?

Summary of the issue: Connecting to test.mosquitto.org or iot.eclipse.org with a keep alive of more than 5 minutes, and everything seems to work just as expected. Connecting to my broker (both on ...
10
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2answers
420 views

Detecting IoT devices in web browser?

Recently I bought a couple of wifi relays from Xiaomi. While they have been solid so far, I really dislike Xiaomi's app. But, I do like the idea that it actually works both in LAN and over the ...
9
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1answer
775 views

3G SIM5320 support for MQTT

Looking for feedback from others who have been using the SIM53xx series modules for IoT solutions over the 3G network. I have an MQTT broker on the internet to collect data for a fleet tracking system ...
7
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1answer
708 views

MQTT: Can a subscriber send data to a producer asynchronously?

Scenario IoT device (currently IPv4 device) that sends via TCP socket a payload to a server once per day. The server has a public IP address, the device is behind a router/NAT. I'm going to use a ...
10
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2answers
3k views

Is MQTT scalable with 1000+ clients?

Scenario IoT device (currently IPv4 device) that sends via TCP socket a payload to a server once per day. The server has a public IP address, the device is behind a router/NAT. I'm going to use a ...
5
votes
1answer
161 views

Deploy Scripts to AWS-Greengrass without AWS-Lambda

Is it possible to deploy to Greengrass from another source besides Lambda? Could I possibly connect to AWS-Greengrass with a client like MQTT.fx and deploy scripts to it? I have tried several times ...
5
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1answer
602 views

How long between PINGREQ and PINGRESP on Mosquitto broker?

I have been chasing a problem with seemingly-random and infrequent disconnects due to "Socket error on client" between my ESP8266 client (PubSubClient 2.6.0) and my Mosquitto broker on Raspberry Pi (...
3
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1answer
301 views

Program with MQTT hanging after starting, LDR processing is not working with no MQTT messages

I am trying to connect the LDR sensor to IoT by using GPIO pins (pin 4) of Raspberry Pi kit and publish MQTT messages. I am using a laser as a transmitter and the LDR sensor as a receiver, the output ...
3
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1answer
284 views

Cannot publish AWS IoT messages from Raspberry Pi

I run a simple publish message from a Raspberry Pi. It seems that my device is connected to AWS IoT, but the message is not publishing and the on_connect and on_publish methods are not invoking. Can ...
-1
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1answer
161 views

How to trigger a function in SIM800C Module using an SMS from AWS IOT? [closed]

I am using a SIM800C Module with AWS IoT. I want to be able to trigger some code running on my device by sending an SMS from AWS. I can generate the SMS OK, but I'm stuck with how to get this to ...
8
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2answers
432 views

Should I use the MQTT protocol?

I am planning to start to implement the below IoT use case. Use case The IoT devices will send 100k messages/minute to the gateway via repeaters and the gateway will transfer the messages to the ...
3
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1answer
356 views

Recommendation to choose API development open source Language, Framework and Database

I'm working in a IoT project and my role is to provide APIs to allow devices to communicate with server/database. I have decided to use MySql for relational data like user details etc.. and MongoDb ...
7
votes
1answer
619 views

SIM5320 MQTT TCP connection closing unexpectedly after time

I have been working on an MQTT protocol using the SIM5320. I am familiar with the AT command documentation, and have a working implementation with an Arduino. Firstly, I open a network socket with AT+...
6
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1answer
1k views

How can I get access to a public MQTT broker's (like iot.eclipse.org) logs?

There was this recent question in which the OP used iot.eclipse.org as an MQTT broker. This server actually runs the latest released version of Mosquitto broker. I have advised to check the ...
6
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1answer
555 views

The MQTT Paho Python code doesn't work properly

This question is related to this one, I created the code below: import paho.mqtt.client as mqtt import time import serial # Open grbl serial port s = serial.Serial('COM3',9600) # Wake up grbl s....
4
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0answers
49 views

Job / Run Loop manager for embedded device?

I'm in process of creating an IoT Prototype which runs (currently) on ARM processor with Embedded Linux. I'm trying to use existing technologies as much as possible: for example MQTT for external ...
2
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1answer
1k views

Questions about MQTT max message size

I am using MQTT Paho, and I have 2 questions about it: How many words can I send as a payload message? For example, can I send all lines below as one payload? O1000 T1 M6 (Linear / Feed - Absolute) ...
8
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2answers
533 views

What right hardware to use for Home Automation using MQTT?

I have been working on a home automation project lately. It is complete to the extent of switch control and getting the readings of temperature, humidity. I am using a Raspberry Pi 3 as MQTT broker. ...
8
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2answers
351 views

AWS IoT implementation on a low end controller like Atmega328, nrf51822?

I have been using AWS IoT implemented in a RPi for a while. I was wondering if I could use a controller like Atmega328 or some NRF based controllers or STM32 to publish and subscribe to AWS IoT MQTT ...
5
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0answers
197 views

Offline messages not being send to Adafruit IoT portal by Mosquitto broker

I have a Raspberry Pi in which I have installed Mosquitto broker and MQTT. Pi is connected to sensor and I need to send this data to Adafruit IoT protal. I am able to send all the data when the Pi is ...
3
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0answers
671 views

How to turn a router into CoAP server or MQTT broker [closed]

Can we turn a router to a MQTT broker or CoAP server? or can we just take additional service from the router by installing CoAP or MQTT broker on it, probably in Java. The router can be powerful as ...
10
votes
1answer
832 views

Non-IP device Communication Protocols

I have a question about Non-IP device communication. From my research, I learnt CoAP and DDS can be used for Device-to-Device communication. MQTT is useful for Device-to-Gateway or Device-to-Service ...
3
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0answers
234 views

Watchdog timer changed router and esp8266 behaviour [closed]

I am working on a home automation project where Pi is acting as broker and ESP8266-01 are acting as clients using Node-Red interface. The ESP acts differently almost everytime I recycle the power. At ...
14
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1answer
752 views

Are there any devices with open-source protocols over Wi-Fi?

I know how to program IoT using Arduino; but I want some ready made portable IoT devices that do not need any programming at device side. Just I want to buy and add these devices to the network (after ...
5
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1answer
2k views

Can multiple subscribers subscribe to the same topic from AWS IoT?

Just like what the question asks, can multiple subscribers subscribe to the same topic reading the same message from AWS IoT?
4
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1answer
687 views

How to setup mosquitto public broker in linux server?

I have linux server running with public ip. I have set up mosquitto broker with the following commands. apt-get install mosquitto apt-get install libmosquitto-dev apt-get install mosquitto-clients ...
9
votes
1answer
936 views

Controlling ESP8266 via Raspberry Pi through MQTT

I am working on a home automation project. The basic objective of my project is to control relays and other sensors located at different locations. I have set up my Raspberry Pi as an MQTT broker. ...
9
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3answers
2k views

Is there a standardized RPC mechanism for MQTT?

Over on Stack Overflow there is a question about implementing request/response interaction over MQTT. As one answer notes, you can do it by publishing the request on one topic and listening for the ...
7
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6answers
10k views

Can I use an ESP8266 as an MQTT broker?

I am making a home automation project based on star topology. What I am trying to achieve is that one of the nodemcu/ESP8266 acts as a server which is accessible for the outside world and other ...
2
votes
1answer
932 views

Connect Webpage to AWS IoT to Publish Messages

I want to create an IoT system. My system contains a robotic arm, a CNC machine and a web page. I want to use MQTT in which I can publish from my web page to robotic arm to pick up the object and put ...
9
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3answers
8k views

MQTT broker accessible from outside without opening port in firewall?

I'd like my MQTT broker to be accessible from outside my home network, but I'm a bit reluctant to open a port in the firewall. And I'd like to avoid using my home IP. It's pretty convenient to have ...
4
votes
1answer
500 views

Connect CNC machine to AWS IoT

I want to connect my CNC machine with AWS IoT within a system that contains a robotic arm and sensor. The CNC machine is connected to a laptop and runs with Python code. I want to use MQTT to make the ...
10
votes
1answer
317 views

Would RPI 3 serve as IoT server with MQTT?

I answered to the below linked question and started to think, what are the hardware specs for running an IoT stack of for example MQTT over LoraWan? Would Raspberry PI 3 survive or not? I do not care ...
12
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2answers
5k views

Is MQTT protocol appropriate for transmitting sensor readings over BLE?

Assume that there are numerous weak sensors (e.g., Arduino level devices) which rely on BLE as means of communication and that these devices are connected to a more powerful gateway (e.g., Raspberry ...
7
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1answer
425 views

Traffic Shaping and MQTT

There are two MQTT Brokers, the connection between them should enable traffic shaping. Broker A has multiple clients who publish data, Broker B has multiple subscriptions. Is there a possibility to ...
10
votes
1answer
2k views

Can I publish multiple MQTT topics in a single request?

I've got a device with multiple sensors that publishes each sensor reading separately to topics like device1-id/sensor1-id = 10.2 device1-id/sensor2-id = 15.5 [...] We feed it to AWS IoT using ...
8
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2answers
545 views

How to link LoRaWAN Server with WSO2 IoT through MQTT

I have been working on creating my private LoRaWAN network using some nodes with A Dragino Sheild and a LG01 Gateway, so far I have been successful in sending the data to this Open Source Server https:...
8
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2answers
7k views

List clients subscribed to a certain topic in Mosquitto server

So that is the general question, but I'll provide the scenario here. I'm running Mosquitto server to provide mqtt comm between esp relay modules (Sonoff from Itead) and Home Assistant. Most of the ...
7
votes
1answer
322 views

Prevent ping logging in Mosquitto server

Is there any way to prevent PINGREQ and PINGRESP to be logged, keeping all other log_type(s) active? I'm looking for a way to prevent only ping entries to be logged. Here is my mosquitto.conf: ...
6
votes
1answer
204 views

MQTT packet validity check

Is there any tool to check my generated packets for being a valid MQTT (3.1.1) packet? Background: I'm using Paho embedded (MQTTPacket) on my microcontroller to generate packets to be send over my ...
10
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3answers
2k views

Performance of MQTT over TLS vs. MQTT

While MQTT is quite versatile it is also not secured on itself. This is by design. According to Stanford-Clark, security was consciously left out of the protocol initially because he and Nipper ...
9
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2answers
1k views

Do I need to use MQTT or HTTP?

I'm working on a device that sense and collect information from the environment such as temperature, humidity, etc. The device is not connected to any power source, but it has a battery, and a solar ...
16
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2answers
13k views

What is the difference between MQTT and Web Sockets, and when should I use them?

What are the major differences between MQTT and Web Sockets? When using IoT for home automation - control and monitoring access over different devices, which one of them should be used when Rest API ...
9
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2answers
513 views

Protocol for configuring IoT device settings

MQTT is widely used in IoT when it comes to exchanging application data between the end device and the host service. The publish-subscribe model makes it easy to use: no handshaking, negotiating etc (...
11
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2answers
793 views

How can I set up main and failover MQTT subscribers for a job queue with AWS IoT?

I have an system where a client (let's call it ClientA) can publish requests to a particular MQTT topic. The broker, in case it matters, is Amazon Web Services. Then I have another client (let's call ...
8
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4answers
8k views

How to enable WebSockets on Mosquitto running on Windows?

I have a Mosquitto broker up and running on my Windows machine. I don't remember if I installed it with Web Sockets support (Cause I didn't knew what that was, or if I needed it). But seeing now my ...
10
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1answer
4k views

How to use MQTT on Arduino which uses serial com to send AT commands to ESP8266

I just started looking into MQTT protocol. Situation In my college project, currently, I use Arduino as main MCU and do every work in that and use Serial Comm. to send AT commands to esp8266 (for ...
8
votes
2answers
6k views

How can I interface a LoraWan network with MQTT?

I have been working on a project which involves creating a LoraWan network using: Dragino lg01 as a Gateway. An Arduino Uno and a Dragino Lora shield with a simple LM35 Temperature sensor As for the ...