Connect Raspberry Pi online simulator to Azure IoT Hub (Node.js)

In this tutorial, you begin by learning the basics of working with Raspberry Pi online simulator. You then learn how to seamlessly connect the Pi simulator to the cloud by using Azure IoT Hub.

If you have physical devices, visit Connect Raspberry Pi to Azure IoT Hub to get started.

What you do

  • Learn the basics of Raspberry Pi online simulator.
  • Create an IoT hub.
  • Register a device for Pi in your IoT hub.
  • Run a sample application on Pi to send simulated sensor data to your IoT hub.

Connect simulated Raspberry Pi to an IoT hub that you create. Then you run a sample application with the simulator to generate sensor data. Finally, you send the sensor data to your IoT hub.

What you learn

  • How to create an Azure IoT hub and get your new device connection string. If you don't have an Azure account, create a free Azure trial account in just a few minutes.
  • How to work with Raspberry Pi online simulator.
  • How to send sensor data to your IoT hub.

Overview of Raspberry Pi web simulator

Click the button to launch Raspberry Pi online simulator.

There are three areas in the web simulator.

  1. Assembly area - The default circuit is that a Pi connects with a BME280 sensor and an LED. The area is locked in preview version so currently you cannot do customization.

  2. Coding area - An online code editor for you to code with Raspberry Pi. The default sample application helps to collect sensor data from BME280 sensor and sends to your Azure IoT Hub. The application is fully compatible with real Pi devices.

  3. Integrated console window - It shows the output of your code. At the top of this window, there are three buttons.

    • Run - Run the application in the coding area.
    • Reset - Reset the coding area to the default sample application.
    • Fold/Expand - On the right side there is a button for you to fold/expand the console window.


The Raspberry Pi web simulator is now available in preview version. We'd like to hear your voice in the Gitter Chatroom. The source code is public on Github.

Overview of Pi online simulator

Create an IoT hub

This section describes how to create an IoT hub using the Azure portal.

  1. Log in to the Azure portal.

  2. Choose +Create a resource, then choose Internet of Things.

  3. Click Iot Hub from the list on the right. You see the first screen for creating an IoT hub.

    Screenshot showing creating a hub in the Azure portal

    Fill in the fields.

    Subscription: Select the subscription to use for your IoT hub.

    Resource Group: You can create a new resource group or use an existing one. To create a new one, click Create new and fill in the name you want to use. To use an existing resource group, click Use existing and select the resource group from the dropdown list. For more information, see Use resource groups to manage your Azure resources.

    Region: This is the region in which you want your hub to be located. Select the location closest to you from the dropdown list.

    IoT Hub Name: Put in the name for your IoT Hub. This name must be globally unique. If the name you enter is available, a green check mark appears.


    The IoT hub will be publicly discoverable as a DNS endpoint, so make sure to avoid any sensitive information while naming it.

  4. Click Next: Size and scale to continue creating your IoT hub.

    Screenshot showing setting size and scale for a new IoT hub using the Azure portal

    On this screen, you can take the defaults and just click Review + create at the bottom.

    Pricing and scale tier: You can choose from several tiers depending on how many features you want and how many messages you send through your solution per day. The free tier is intended for testing and evaluation. It allows 500 devices to be connected to the IoT hub and up to 8,000 messages per day. Each Azure subscription can create one IoT Hub in the free tier.

    IoT Hub units: The number of messages allowed per unit per day depends on your hub's pricing tier. For example, if you want the IoT hub to support ingress of 700,000 messages, you choose two S1 tier units.

    For details about the other tier options, see Choosing the right IoT Hub tier.

    Advanced / Device-to-cloud partitions: This property relates the device-to-cloud messages to the number of simultaneous readers of the messages. Most IoT hubs only need four partitions.

  5. Click Review + create to review your choices. You see something similar to this screen.

    Screenshot reviewing information for creating the new IoT hub

  6. Click Create to create your new IoT hub. Creating the hub takes a few minutes.

Retrieve connection string for IoT hub

After your hub has been created, retrieve the connection string for the hub. This is used to connect devices and applications to your hub.

  1. Click on your hub to see the IoT Hub pane with Settings, and so on. Click Shared access policies.

  2. In Shared access policies, select the iothubowner policy.

  3. Under Shared access keys, copy the Connection string -- primary key to be used later.

    Show how to retrieve the connection string

    For more information, see Access control in the "IoT Hub developer guide."

Register a new device in the IoT hub

In this section, you create a device identity in the identity registry in your IoT hub. A device cannot connect to IoT hub unless it has an entry in the identity registry. For more information, see the "Identity registry" section of the IoT Hub developer guide

  1. In your IoT hub navigation menu, open IoT Devices, then click Add to register a new device in your IoT hub.

    Create device identity in portal

  2. Provide a name for your new device, such as myDeviceId, and click Save. This action creates a new device identity for your IoT hub.

    Add a new device


    The device ID may be visible in the logs collected for customer support and troubleshooting, so make sure to avoid any sensitive information while naming it.

  3. After the device is created, open the device from the list in the IoT devices pane. Copy the Connection string---primary key to use later.

    Device connection string


The IoT Hub identity registry only stores device identities to enable secure access to the IoT hub. It stores device IDs and keys to use as security credentials, and an enabled/disabled flag that you can use to disable access for an individual device. If your application needs to store other device-specific metadata, it should use an application-specific store. For more information, see IoT Hub developer guide.

Run a sample application on Pi web simulator

  1. In coding area, make sure you are working on the default sample application. Replace the placeholder in Line 15 with the Azure IoT hub device connection string. Replace the device connection string

  2. Click Run or type npm start to run the application.

You should see the following output that shows the sensor data and the messages that are sent to your IoT hub Output - sensor data sent from Raspberry Pi to your IoT hub

Next steps

You’ve run a sample application to collect sensor data and send it to your IoT hub.

To continue to get started with Azure IoT Hub and to explore other IoT scenarios, see the following: