Visualizing Temperature in V-VAC Using DeltaT | IoT MQTT Dashboard for Real-Time Data

Monitoring temperature is a key part of any IoT automation system. In this project, we’ll use the VOLKKOMMEN® DeltaT Wi-Fi temperature sensor and connect it to the V-VAC IoT Platform using MQTT, one of the most reliable IoT communication protocols. You’ll learn how to set up a real-time temperature dashboard, send data to the cloud, and visualize live readings for predictive maintenance and smart environment monitoring.

This guide helps beginners and professionals alike understand how to build an IoT temperature monitoring device, configure MQTT settings, and design a fully functional IoT dashboard for data visualization — all without complex coding.

Hardware Components

1. DeltaT Wi-Fi (VOLKKOMMEN®)
2. Temperature sensor (DS18B20)
3. 5V, 1A DC Power Adapter (for DeltaT Wi-Fi)
4. Laptop / PC for configuration
5. Wi-Fi Router / Access Point
6. Screwdriver and wire stripper for connections
7. Connecting wires

Software Components

1. Web Browser (Google Chrome / Edge)
2. Wi-Fi Access Credentials (SSID and Password)
3. Network Analyzer Tool (to find the device — IP optional)

Power off both devices before wiring.

LED Status Indications

1. White: Booting
2. Cyan fading: Scanning Wi-Fi
3. Green: Connected to Wi-Fi
4. Purple: Configuration mode active

You can display and analyze this data using the VOLKKOMMEN V-VAC Platform: V-VAC

Steps to Connect V-VAC :

1. Log in to your V-VAC account. (Create a new account if not signed up already.)
2. In the Devices section add a new device.
3. Select common device and enter the details of the device.
4. Copy the Device Token and paste it in the MQTT section of the DeltaT Wi-Fi Web Interface.

For further details check out (How to connect to V-VAC).

Enter Configuration Mode.

1. Press the Config button on the DeltaT Wi-Fi device.
2. The Status LED will turn purple, indicating that the device is now in configuration mode.

Connect to the DeltaT Wi-Fi Network.

1. On your laptop or smartphone, open the list of available Wi-Fi networks.
2. Select:

SSID: DeltaT Wi-Fi (Your_Device_Name)

1. When prompted for a password, enter:

Password: 12345678

1. Once connected, keep this network active — it will allow access to the configuration interface.

Open the Configuration Page.

1. Open a web browser (Google Chrome or Edge recommended).
2. In the address bar, type:

192.168.4.1

1. Press Enter — the Main Menu Page will open.
2. Click on “Configure Wi-Fi” to proceed to the network settings screen.

Add Your Wi-Fi Details

1. In the Wi-Fi Settings page, enter your router details:
2. SSID :Your_WiFi_Name
3. Password :Your_WiFi_Password
4. Click Save Settings.
5. The device will automatically restart and connect to your Wi-Fi network.

💡 Tip: Once it reconnects, the Status LED will change from blue (not connected) to green (connected).

Find the Device IP Address

1. Open your Wi-Fi router’s connected device list or use a network scanner app (like Fing or Advanced IP Scanner).
2. Locate DeltaT Wi-Fi in the device list — note down its IP address.
3. Use this IP to access the DeltaT Wi-Fi web interface for further configuration.

Access the DeltaT Wi-Fi Web Interface.

1. Open a web browser and enter the IP address you found in Step 3.
2. The login page will appear.
3. Enter the default credentials:

Username: User@volk.com

Password: Pass@123

1. Click Login to access the main dashboard.

Open the Setup Menu.

1. Once logged in, you’ll see the Main Menu.
2. Click on the “Setup” option.
3. This will open the Cloud Settings Page.

Configure MQTT Parameters.

Fill in the following details according to your cloud or broker settings:

Parameter : Value

Server : data.volkkommen.com

Port : 1883

Username :from V-VAC platform (Devices → Setup)

Password :from V-VAC platform (Devices → Setup)

Topic :from V-VAC platform (Devices → Setup)

example → Topic : f898f4a51628f4eb replace it with Device tokenfrom V-VAC platform (Devices).

data-1 : Required interval to send data

Min. relative change in (%) : specifies the minimum percentage change in value required to trigger instant polling.

Min. absolute change in value : defines the minimum change in value needed to initiate instant polling.

Device Name : can be modified for easier identification.

Note : The device name should be less than 15 characters and avoid using spaces between characters

Save and Apply Settings

1. Review all fields carefully.
2. Click “Save” to apply the settings.
3. Once successful, you’ll see green LED indicating an active Wi-Fi and MQTT connection.

1. In Dashboard section you can configure widgets for your required data.
2. Click “Create Dashboard”.
3. Give your dashboard a name (e.g., Smart Sensor Dashboard).
4. Click the 3rd icon in the dashboard to open the dashboard.
5. Inside the dashboard editor, click “Edit” and click "Add Widget" to add new widgets.
6. In the selection menu choose any widget based on your data visualization needs.

For example:

Card: For displaying single-value metrics

Line Chart: For continuous data

Bar Graph: For comparing sensor readings

Geo Map: For displaying the location of the device.

Thermometer: For displaying the range of the data.

Radial Bar: For displaying the data.

1. Link each widget to a device telemetry key (the data your device sends).
2. After customizing your widget, click the Show on Dashboard button to display it on the dashboard.
3. To save your changes, click the Save button at the top-right corner of the dashboard.
4. You’ll now see live charts and readings updating automatically.

For more IoT projects and tutorials, visit the official V-VAC Platform - V-VAC.