Guys, I've heard of this MQTT protocol but I'm not entirely sure how it works. Why is it particularly preferred in IoT projects? Does it follow a server-client model or does it use a publish/subscribe system? I'm thinking of using it in a small project but I'm curious about the best way to approach it. In your opinion, in which scenarios is it most beneficial?
What is MQTT? What are its use cases?
👁️ 1 views💬 3 replies❤️ 0 likes
3 Replies
So you're curious about MQTT too, huh buddy? Because we can basically call this protocol the backbone of IoT. The basic idea is actually pretty simple: it works on a publish/subscribe system, meaning the "publisher" (like a sensor) sends the data, and the "subscribers" (devices that want that data) receive it. It's not a direct server-client setup; there's an intermediary server called a broker. The sensor (publish) sends a "hello" to the broker, and your smart home device (subscribe) tells the broker, "I want to subscribe to the 'hello' topic," and that's how the communication happens.
I think I should list the most useful scenarios:
1) Home automation, like taking data from a temperature sensor to control the heater,
2) Monitoring the status of machines in industrial facilities,
3) Soil moisture sensors in smart agriculture.
I used MQTT last year for a drone project I was working on, to display sensor data, and it worked synchronously with the publish-subscribe system without any hassle. If you're planning to work on a small project, set up a broker on a Raspberry Pi (I recommend Mosquitto, super easy to install), then send sensor data with an ESP8266/ESP32, and subscribe to the data with another device. Sending the data in JSON format will also be useful for your future projects.
I've used MQTT extensively in my previous IoT projects, especially for transmitting sensor data to the cloud. This protocol operates on a publish/subscribe system; devices (publishers) send data to "topics," and other devices or servers (subscribers) subscribe to those topics to receive the data. For example, in a home automation setup, I had a thermostat publishing temperature data to a "sensors/temperature" topic, and a smart display subscribed to that topic to display the data. It might seem like a server-client model, but you can actually run it locally with MQTT brokers like Mosquitto without needing a corporate server, which reduces both cost and complexity.
My recommendation is to test a small project by setting up a Raspberry Pi with a sensor (like a DHT11) and a Mosquitto broker, then sending the collected data to your phone via MQTT. There’s a simple Arduino example code called “MQTT with Arduino and Raspberry Pi” that you can use to walk through the publish/subscribe process step by step. MQTT is most commonly used in IoT for home automation, monitoring systems (e.g., soil moisture in agriculture), and even remote control of industrial devices. If your project needs to operate with low bandwidth and minimal battery consumption, MQTT is ideal for you.
MQTT is a must in the IoT world—especially when transmitting sensor data or communicating with low-power devices. It operates on a publish/subscribe model, so there’s no "client-server" setup; instead, you have "publishers" (sensor devices) and "subscribers" (cloud platforms, dashboards). Plus, it uses TCP/IP minimally, which is a huge advantage for bandwidth and battery life.
I first used MQTT in a thermostat project; thanks to MQTT, the device could send temperature data every 30 seconds and then go into sleep mode. I set it up in five minutes using a tiny ESP8266 and a free broker (Mosquitto). If you're just starting out, try writing a simple subscriber script in Python or Node.js and test it with a client like MQTT.fx—it really speeds up learning!