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.

Connect Raspberry Pi web simulator to Azure IoT Hub

Start Raspberry Pi simulator

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.

You first connect the simulated Raspberry Pi to an IoT hub that you create. You then run a sample application with the simulated Pi 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

Select the following button to start Raspberry Pi online simulator.

There are three areas in the web simulator.

  1. Assembly area - A graphic depiction of the Pi simulator, and any simulated devices and connections.

    By default, the assembly area simulates connections from the Pi to two devices:

    • A BME280 humidity sensor connected to I2C.1
    • An LED connected to GPIO 4

    The assembly area is locked in this preview version, so you currently can't customize the assembly.

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

  3. Integrated console window - A window that 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.

    • Collapse/Expand - On the right side, there's a button for you to collapse or expand the console window.


The Raspberry Pi web simulator is currently available in a 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. Sign in to the Azure portal.

  2. On the Azure homepage, select the + Create a resource button.

  3. From the Categories menu, select Internet of Things, and then select IoT Hub.

  4. On the Basics tab, complete the fields as follows:


    Because the IoT hub will be publicly discoverable as a DNS endpoint, be sure to avoid entering any sensitive or personally identifiable information when you name it.

    Property Value
    Subscription Select the subscription to use for your hub.
    Resource group Select a resource group or create a new one. To create a new one, select Create new and fill in the name you want to use.
    IoT hub name Enter a name for your hub. This name must be globally unique, with a length between 3 and 50 alphanumeric characters. The name can also include the dash ('-') character.
    Region Select the region, closest to you, where you want your hub to be located. Some features, such as IoT Hub device streams, are only available in specific regions. For these limited features, you must select one of the supported regions.
    Tier Select the tier that you want to use for your hub. Tier selection depends 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. The free tier allows 500 devices to be connected to the hub and up to 8,000 messages per day. Each Azure subscription can create one IoT hub in the free tier.

    To compare the features available to each tier, select Compare tiers. For more information, see Choose the right IoT Hub tier for your solution.
    Daily message limit Select the maximum daily quota of messages for your hub. The available options depend on the tier you've selected for your hub. To see the available messaging and pricing options, select See all options and select the option that best matches the needs of your hub. For more information, see IoT Hub quotas and throttling.

    Screen capture that shows how to create an IoT hub in the Azure portal.


    Prices shown are for example purposes only.

  5. Select Next: Networking to continue creating your hub.

  6. On the Networking tab, complete the fields as follows:

    Property Value
    Connectivity configuration Choose the endpoints that devices can use to connect to your IoT hub. Accept the default setting, Public access, for this example. You can change this setting after the IoT hub is created. For more information, see Managing public network access for your IoT hub.
    Minimum TLS Version Select the minimum TLS version to be supported by your IoT hub. Once the IoT hub is created, this value can't be changed. Accept the default setting, 1.0, for this example.

    Screen capture that shows how to choose the endpoints that can connect to a new IoT hub.

  7. Select Next: Management to continue creating your hub.

  8. On the Management tab, accept the default settings. If desired, you can modify any of the following fields:

    Property Value
    Permission model Part of role-based access control, this property decides how you manage access to your IoT hub. Allow shared access policies or choose only role-based access control. For more information, see Control access to IoT Hub by using Azure Active Directory.
    Assign me You may need access to IoT Hub data APIs to manage elements within an instance. If you have access to role assignments, select IoT Hub Data Contributor role to grant yourself full access to the data APIs.

    To assign Azure roles, you must have Microsoft.Authorization/roleAssignments/write permissions, such as User Access Administrator or Owner.
    Device-to-cloud partitions This property relates the device-to-cloud messages to the number of simultaneous readers of the messages. Most IoT hubs need only four partitions.

    Screen capture that shows how to set the role-based access control and scale for a new IoT hub.

  9. Select Next: Add-ons to continue to the next screen.

  10. On the Add-ons tab, accept the default settings. If desired, you can modify any of the following fields:

    Property Value
    Enable Device Update for IoT Hub Turn on Device Update for IoT Hub to enable over-the-air updates for your devices. If you select this option, you're prompted to provide information to provision a Device Update for IoT Hub account and instance. For more information, see What is Device Update for IoT Hub?
    Enable Defender for IoT Turn Defender for IoT on to add an extra layer of protection to IoT and your devices. This option isn't available for hubs in the free tier. Learn more about security recommendations for IoT Hub in Defender for IoT.

    Screen capture that shows how to set the optional add-ons for a new IoT hub.


    Prices shown are for example purposes only.

  11. Select Next: Tags to continue to the next screen.

    Tags are name/value pairs. You can assign the same tag to multiple resources and resource groups to categorize resources and consolidate billing. In this document, you won't be adding any tags. For more information, see Use tags to organize your Azure resources.

    Screen capture that shows how to assign tags for a new IoT hub.

  12. Select Next: Review + create to review your choices.

  13. Select Create to start the deployment of your new hub. Your deployment will be in progress a few minutes while the hub is being created. Once the deployment is complete, select Go to resource to open the new hub.

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 can't connect to a hub unless it has an entry in the identity registry. For more information, see the IoT Hub developer guide.

  1. In your IoT hub navigation menu, open Devices, then select Add Device to add a device in your IoT hub.

    Screen capture that shows how to create a device identity in the portal.

  2. In Create a device, provide a name for your new device, such as myDeviceId, and select Save. This action creates a device identity for your IoT hub. Leave Auto-generate keys checked so that the primary and secondary keys will be generated automatically.

    Screen capture that shows how to 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 Devices pane. Copy the value of Primary connection string. This connection string is used by device code to communicate with the IoT hub.

    By default, the keys and connection strings are masked because they're sensitive information. If you click the eye icon, they're revealed. It's not necessary to reveal them to copy them with the copy button.

    Screen capture that shows the 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 the coding area, make sure you're working with the default sample application. Replace the placeholder in line 15 with the Azure IoT hub device connection string.

    Replace the device connection string

  2. Select Run or type npm start in the integrated console window 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

Read the messages received by your hub

One way to monitor messages received by your IoT hub from the simulated device is to use the Azure IoT Hub extension for Visual Studio Code. To learn more, see Use the Azure IoT Hub extension for Visual Studio Code to send and receive messages between your device and IoT Hub.

For more ways to process data sent by your device, continue on to the next section.

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 all extended IoT scenarios, see the following: