How to add an MQTT device in Home Assistant on the EG5120 edge gateway

So, you've got the powerful Robustel EG5120 edge gateway, and you're running Home Assistant on it. Smart move. You've already bypassed the limitations of a typical Raspberry Pi, opting for an industrial-grade platform with a stable Debian OS that's built for the long haul. But let's be clear: the real magic happens when you start connecting devices. In my experience, the most flexible and powerful way to do that in the IoT world is with MQTT.

What's the plan? We're going to bridge the gap between your industrial hardware and a truly smart, local automation hub. Forget relying on the cloud for every little action. We're going to set up an MQTT Home Assistant integration right on your EG5120. I'll guide you through connecting a typical MQTT-enabled smart plug, from initial setup to seeing its data pop up live on your dashboard. It's easier than you think, isn't it?

Let's dive into the hands-on process. For this walkthrough, I'm using a common scenario: integrating an MQTT smart plug to monitor the power status of a piece of equipment. This is incredibly useful in an industrial setting for tracking machine uptime or energy consumption.

Before we roll up our sleeves and dive in, let's make sure you have everything you need. Here’s a quick checklist:

• Hardware:
  • A Robustel EG5120 Industrial Edge Computing Gateway.
  • The appropriate power supply for the gateway.
  • An Ethernet cable for the initial setup.
  • A computer with a web browser.
  • An MQTT-enabled device you want to integrate (we're using a smart plug as an example).
• Software & Setup:
  • Your EG5120 must have Home Assistant and HACS installed. For detailed steps, you can refer to " How to Install Home Assistant on an Industrial IoT Gateway (EG5120)".
  • You need an MQTT Broker, like Mosquitto, already installed and running on the EG5120. For detailed steps, you can refer to " How to install an MQTT Broker for Home Assistant on the EG5120".
  • For easier editing, it's recommended to have a file editor add-on (like the 'File editor' from HACS) installed in Home Assistant. For detailed steps, you can refer to " How to install an file editor for Home Assistant on the EG5120".

First things first, we need to access the Home Assistant interface running on the EG5120. It's a straightforward process.

1. Power Up: Connect the power supply to your EG5120 gateway and give it a solid minute to fully boot up. The RUN LED should be blinking.
2. Physical Connection: Use an Ethernet cable to connect the gateway's LAN port directly to your computer.
3. Network Configuration: Set your computer's IPv4 network card settings to obtain an IP address automatically (via DHCP). Your EG5120 will handle the rest.
4. Access Home Assistant: Open your web browser and navigate to http://192.168.0.1:8123. This is the default address. The real 'aha!' moment for many engineers is realizing that if the device has been used before, the gateway IP might be different. You can easily find the correct address by checking the "Default Gateway" IP in your computer's network details after connecting.

With Home Assistant up and running, it's time to teach it how to speak MQTT. This involves adding the core integration that listens for MQTT messages.

• Navigate to Integrations: Once you've logged into your Home Assistant account (create one if it's your first time), go to Settings > Devices & services.
• Add MQTT: You'll land on the Integrations page. Click the ADD INTEGRATION button in the bottom right corner. In the search box that appears, type MQTT and click on the result.
• Configure the Home Assistant MQTT Client: Here's the crucial part. The "Broker" is the central message hub. Since we are running everything locally on the EG5120, the IP address you need to enter is 127.0.0.1. This is a universal IP address that simply means "this device itself" (also known as localhost). Leave the port as 1883 and submit. You should see a success message!

We need to tell our MQTT Home Assistant setup how to read this. We'll do this by editing the main configuration file.

1. Open the File Editor: I recommend using the 'File editor' add-on from the HACS (Home Assistant Community Store) for this. Navigate to it and open the configuration.yaml file.
2. Add the MQTT Sensor Configuration: Scroll to the bottom of the file and add the following code block. This tells Home Assistant to listen on the specified topic and create sensors for each piece of data in the JSON payload.

3. Save and Restart: Save the file, then go to Developer Tools > YAML and click RESTART. This will apply your changes. For more advanced configuration options, the official Home Assistant MQTT documentation (external link) is an excellent resource. You can also explore our other guides on industrial IoT edge gateways.

Once Home Assistant restarts, the magic is complete. Navigate back to your main Overview dashboard. Home Assistant is usually smart enough to automatically add your new sensors as cards on the dashboard. You'll see the real-time voltage, current, power, and switch status of your smart plug. You've successfully integrated a physical device into your local smart hub using MQTT Home Assistant. Now, you can use this data to build powerful automations, track energy usage, or create alerts—all processed securely and locally on your Robustel EG5120.