Quickstart: Control a device connected to an IoT hub

Članak
11/24/2021
34 min. za čitanje

In this quickstart, you use a direct method to control a simulated device connected to your IoT hub. IoT Hub is an Azure service that lets you manage your IoT devices from the cloud and ingest high volumes of device telemetry to the cloud for storage or processing. You can use direct methods to remotely change the behavior of devices connected to your IoT hub.

The quickstart uses two pre-written .NET applications:

A simulated device application that responds to direct methods called from a service application. To receive the direct method calls, this application connects to a device-specific endpoint on your IoT hub.
A service application that calls the direct methods on the simulated device. To call a direct method on a device, this application connects to service-side endpoint on your IoT hub.

Prerequisites

An Azure account with an active subscription. Create one for free.
The two sample applications you run in this quickstart are written using C#. You need the .NET Core SDK 3.1 or greater on your development machine.

You can download the .NET Core SDK for multiple platforms from .NET.

You can verify the current version of C# on your development machine using the following command:
```
dotnet --version
```
If you haven't already done so, download the Azure IoT C# samples from https://github.com/Azure-Samples/azure-iot-samples-csharp/archive/main.zip and extract the ZIP archive.
Make sure that port 8883 is open in your firewall. The device sample in this quickstart uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see Connecting to IoT Hub (MQTT).

Use the Bash environment in Azure Cloud Shell.
If you prefer, install the Azure CLI to run CLI reference commands.
- If you're using a local installation, sign in to the Azure CLI by using the az login command. To finish the authentication process, follow the steps displayed in your terminal. For additional sign-in options, see Sign in with the Azure CLI.
- When you're prompted, install Azure CLI extensions on first use. For more information about extensions, see Use extensions with the Azure CLI.
- Run az version to find the version and dependent libraries that are installed. To upgrade to the latest version, run az upgrade.

Note

This article uses the newest version of the Azure IoT extension, called azure-iot. The legacy version is called azure-cli-iot-ext.You should only have one version installed at a time. You can use the command az extension list to validate the currently installed extensions.

Use az extension remove --name azure-cli-iot-ext to remove the legacy version of the extension.

Use az extension add --name azure-iot to add the new version of the extension.

To see what extensions you have installed, use az extension list.

Create an IoT hub

If you completed the previous Quickstart: Send telemetry from a device to an IoT hub, you can skip this step.

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

Sign in to the Azure portal.
From the Azure homepage, select the + Create a resource button, and then enter IoT Hub in the Search the Marketplace field.
Select IoT Hub from the search results, and then select Create.
On the Basics tab, complete the fields as follows:
- 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. To use an existing resource group, select that resource group. For more information, see Manage Azure Resource Manager resource groups.
- Region: Select the region in which you want your hub to be located. Select the location closest to you. 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.
- 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.
Important

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.
Select Next: Networking to continue creating your hub.

Choose the endpoints that devices can use to connect to your IoT Hub. You can select the default setting Public endpoint (all networks), or choose Public endpoint (selected IP ranges), or Private endpoint. Accept the default setting for this example.
Select Next: Management to continue creating your hub.

You can accept the default settings here. If desired, you can modify any of the following fields:
- Pricing and scale tier: Your selected 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 hub and up to 8,000 messages per day. Each Azure subscription can create one IoT hub in the free tier.
  
  If you are working through a Quickstart for IoT Hub device streams, select 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 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.
- Defender for IoT: Turn this on to add an extra layer of threat protection to IoT and your devices. This option is not available for hubs in the free tier. For more information about this feature, see Microsoft Defender for IoT.
- Advanced Settings > Device-to-cloud partitions: This property relates the device-to-cloud messages to the number of simultaneous readers of the messages. Most hubs need only four partitions.
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.
Select Next: Review + create to review your choices. You see something similar to this screen, but with the values you selected when creating the hub.
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 device

If you completed the previous Quickstart: Send telemetry from a device to an IoT hub, you can skip this step.

A device must be registered with your IoT hub before it can connect. In this quickstart, you use the Azure Cloud Shell to register a simulated device.

Run the following command in Azure Cloud Shell to create the device identity.

YourIoTHubName: Replace this placeholder below with the name you chose for your IoT hub.

MyDotnetDevice: This is the name of the device you're registering. It's recommended to use MyDotnetDevice as shown. If you choose a different name for your device, you also need to use that name throughout this article, and update the device name in the sample applications before you run them.
```
az iot hub device-identity create \
  --hub-name {YourIoTHubName} --device-id MyDotnetDevice
```
Run the following commands in Azure Cloud Shell to get the device connection string for the device you just registered:

YourIoTHubName: Replace this placeholder below with the name you chose for your IoT hub.
```
az iot hub device-identity connection-string show \
  --hub-name {YourIoTHubName} \
  --device-id MyDotnetDevice \
  --output table
```
Make a note of the device connection string, which looks like:

HostName={YourIoTHubName}.azure-devices.net;DeviceId=MyNodeDevice;SharedAccessKey={YourSharedAccessKey}

You use this value later in the quickstart.

Retrieve the service connection string

You also need your IoT hub service connection string to enable the service application to connect to the hub and retrieve the messages. The following command retrieves the service connection string for your IoT hub:

az iot hub connection-string show --policy-name service --hub-name {YourIoTHubName} --output table

Make a note of the service connection string, which looks like:

HostName={YourIoTHubName}.azure-devices.net;SharedAccessKeyName=service;SharedAccessKey={YourSharedAccessKey}

You use this value later in the quickstart. This service connection string is different from the device connection string you noted in the previous step.

Listen for direct method calls

The simulated device application connects to a device-specific endpoint on your IoT hub, sends simulated telemetry, and listens for direct method calls from your hub. In this quickstart, the direct method call from the hub tells the device to change the interval at which it sends telemetry. The simulated device sends an acknowledgment back to your hub after it executes the direct method.

In a local terminal window, navigate to the root folder of the sample C# project. Then navigate to the iot-hub\Quickstarts\SimulatedDeviceWithCommand folder.
In the local terminal window, run the following commands to install the required packages for simulated device application:
```
dotnet restore
```
In the local terminal window, run the following command to build and run the simulated device application, replacing {DeviceConnectionString} with the device connection string you noted previously:
```
dotnet run -- {DeviceConnectionString}
```
The following screenshot shows the output as the simulated device application sends telemetry to your IoT hub:

Call the direct method

The service application connects to a service-side endpoint on your IoT Hub. The application makes direct method calls to a device through your IoT hub and listens for acknowledgments. An IoT Hub service application typically runs in the cloud.

In another local terminal window, navigate to the root folder of the sample C# project. Then navigate to the iot-hub\Quickstarts\InvokeDeviceMethod folder.
In the local terminal window, run the following commands to install the required libraries for the service application:
```
dotnet restore
```
In the local terminal window, run the following commands to build and run the service application, replacing {ServiceConnectionString} with the service connection string you noted previously:
```
dotnet run -- {ServiceConnectionString}
```
The following screenshot shows the output as the application makes a direct method call to the device and receives an acknowledgment:

After you run the service application, you see a message in the console window running the simulated device, and the rate at which it sends messages changes:

This quickstart uses two Java applications: a simulated device application that responds to direct methods called from a back-end application and a service application that calls the direct method on the simulated device.

Prerequisites

An Azure account with an active subscription. Create one for free.
Java SE Development Kit 8. In Java long-term support for Azure and Azure Stack, under Long-term support, select Java 8.

You can verify the current version of Java on your development machine using the following command:
```
java -version
```
Apache Maven 3.

You can verify the current version of Maven on your development machine using the following command:
```
mvn --version
```
A sample Java project.
Port 8883 open in your firewall. The device sample in this quickstart uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see Connecting to IoT Hub (MQTT).

Use the Bash environment in Azure Cloud Shell.
If you prefer, install the Azure CLI to run CLI reference commands.
- If you're using a local installation, sign in to the Azure CLI by using the az login command. To finish the authentication process, follow the steps displayed in your terminal. For additional sign-in options, see Sign in with the Azure CLI.
- When you're prompted, install Azure CLI extensions on first use. For more information about extensions, see Use extensions with the Azure CLI.
- Run az version to find the version and dependent libraries that are installed. To upgrade to the latest version, run az upgrade.

Note

Use az extension remove --name azure-cli-iot-ext to remove the legacy version of the extension.

Use az extension add --name azure-iot to add the new version of the extension.

To see what extensions you have installed, use az extension list.

Create an IoT hub

If you completed the previous Quickstart: Send telemetry from a device to an IoT hub, you can skip this step.

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

Sign in to the Azure portal.
From the Azure homepage, select the + Create a resource button, and then enter IoT Hub in the Search the Marketplace field.
Select IoT Hub from the search results, and then select Create.
On the Basics tab, complete the fields as follows:
- 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. To use an existing resource group, select that resource group. For more information, see Manage Azure Resource Manager resource groups.
- Region: Select the region in which you want your hub to be located. Select the location closest to you. 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.
- 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.
Important

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.
Select Next: Networking to continue creating your hub.

Choose the endpoints that devices can use to connect to your IoT Hub. You can select the default setting Public endpoint (all networks), or choose Public endpoint (selected IP ranges), or Private endpoint. Accept the default setting for this example.
Select Next: Management to continue creating your hub.

You can accept the default settings here. If desired, you can modify any of the following fields:
- Pricing and scale tier: Your selected 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 hub and up to 8,000 messages per day. Each Azure subscription can create one IoT hub in the free tier.
  
  If you are working through a Quickstart for IoT Hub device streams, select 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 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.
- Defender for IoT: Turn this on to add an extra layer of threat protection to IoT and your devices. This option is not available for hubs in the free tier. For more information about this feature, see Microsoft Defender for IoT.
- Advanced Settings > Device-to-cloud partitions: This property relates the device-to-cloud messages to the number of simultaneous readers of the messages. Most hubs need only four partitions.
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.
Select Next: Review + create to review your choices. You see something similar to this screen, but with the values you selected when creating the hub.
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 device

If you completed the previous Quickstart: Send telemetry from a device to an IoT hub, you can skip this step.

A device must be registered with your IoT hub before it can connect. In this quickstart, you use the Azure Cloud Shell to register a simulated device.

Run the following command in Azure Cloud Shell to create the device identity.

YourIoTHubName: Replace this placeholder below with the name you chose for your IoT hub.

MyJavaDevice: This is the name of the device you're registering. It's recommended to use MyJavaDevice as shown. If you choose a different name for your device, you also need to use that name throughout this article, and update the device name in the sample applications before you run them.
```
az iot hub device-identity create \
  --hub-name {YourIoTHubName} --device-id MyJavaDevice
```
Run the following commands in Azure Cloud Shell to get the device connection string for the device you just registered:

YourIoTHubName: Replace this placeholder below with the name you choose for your IoT hub.
```
az iot hub device-identity connection-string show\
  --hub-name {YourIoTHubName} \
  --device-id MyJavaDevice \
  --output table
```
Make a note of the device connection string, which looks like:

HostName={YourIoTHubName}.azure-devices.net;DeviceId=MyNodeDevice;SharedAccessKey={YourSharedAccessKey}

You use this value later in the quickstart.

Retrieve the service connection string

You also need a service connection string to enable the back-end application to connect to your IoT hub and retrieve the messages. The following command retrieves the service connection string for your IoT hub:

YourIoTHubName: Replace this placeholder below with the name you chose for your IoT hub.

az iot hub connection-string show --policy-name service --name {YourIoTHubName} --output table

Make a note of the service connection string, which looks like:

HostName={YourIoTHubName}.azure-devices.net;SharedAccessKeyName=service;SharedAccessKey={YourSharedAccessKey}

You use this value later in the quickstart. This service connection string is different from the device connection string you noted in the previous step.

Listen for direct method calls

In a local terminal window, navigate to the root folder of the sample Java project. Then navigate to the iot-hub\Quickstarts\simulated-device-2 folder.
Open the src/main/java/com/microsoft/docs/iothub/samples/SimulatedDevice.java file in a text editor of your choice.

Replace the value of the connString variable with the device connection string you made a note of earlier. Then save your changes to SimulatedDevice.java.
In the local terminal window, run the following commands to install the required libraries and build the simulated device application:
```
mvn clean package
```
In the local terminal window, run the following commands to run the simulated device application:
```
java -jar target/simulated-device-2-1.0.0-with-deps.jar
```
The following screenshot shows the output as the simulated device application sends telemetry to your IoT hub:

Call the direct method

The back-end application connects to a service-side endpoint on your IoT Hub. The application makes direct method calls to a device through your IoT hub and listens for acknowledgments. An IoT Hub back-end application typically runs in the cloud.

In another local terminal window, navigate to the root folder of the sample Java project. Then navigate to the iot-hub\Quickstarts\back-end-application folder.
Open the src/main/java/com/microsoft/docs/iothub/samples/BackEndApplication.java file in a text editor of your choice.

Replace the value of the iotHubConnectionString variable with the service connection string you made a note of earlier. Then save your changes to BackEndApplication.java.
In the local terminal window, run the following commands to install the required libraries and build the back-end application:
```
mvn clean package
```
In the local terminal window, run the following commands to run the back-end application:
```
java -jar target/back-end-application-1.0.0-with-deps.jar
```
The following screenshot shows the output as the application makes a direct method call to the device and receives an acknowledgment:

After you run the back-end application, you see a message in the console window running the simulated device, and the rate at which it sends messages changes:

This quickstart uses two Node.js applications: a simulated device application that responds to direct methods called from a back-end application and a back-end application that calls the direct methods on the simulated device.

Prerequisites

An Azure account with an active subscription. Create one for free.
Node.js 12+.

You can verify the current version of Node.js on your development machine using the following command:
```
node --version
```
A sample Node.js project.
Port 8883 open in your firewall. The device sample in this quickstart uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see Connecting to IoT Hub (MQTT).

Use the Bash environment in Azure Cloud Shell.
If you prefer, install the Azure CLI to run CLI reference commands.
- If you're using a local installation, sign in to the Azure CLI by using the az login command. To finish the authentication process, follow the steps displayed in your terminal. For additional sign-in options, see Sign in with the Azure CLI.
- When you're prompted, install Azure CLI extensions on first use. For more information about extensions, see Use extensions with the Azure CLI.
- Run az version to find the version and dependent libraries that are installed. To upgrade to the latest version, run az upgrade.

Note

Use az extension remove --name azure-cli-iot-ext to remove the legacy version of the extension.

Use az extension add --name azure-iot to add the new version of the extension.

To see what extensions you have installed, use az extension list.

Create an IoT hub

If you completed the previous Quickstart: Send telemetry from a device to an IoT hub, you can skip this step.

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

Sign in to the Azure portal.
From the Azure homepage, select the + Create a resource button, and then enter IoT Hub in the Search the Marketplace field.
Select IoT Hub from the search results, and then select Create.
On the Basics tab, complete the fields as follows:
- 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. To use an existing resource group, select that resource group. For more information, see Manage Azure Resource Manager resource groups.
- Region: Select the region in which you want your hub to be located. Select the location closest to you. 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.
- 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.
Important

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.
Select Next: Networking to continue creating your hub.

Choose the endpoints that devices can use to connect to your IoT Hub. You can select the default setting Public endpoint (all networks), or choose Public endpoint (selected IP ranges), or Private endpoint. Accept the default setting for this example.
Select Next: Management to continue creating your hub.

You can accept the default settings here. If desired, you can modify any of the following fields:
- Pricing and scale tier: Your selected 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 hub and up to 8,000 messages per day. Each Azure subscription can create one IoT hub in the free tier.
  
  If you are working through a Quickstart for IoT Hub device streams, select 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 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.
- Defender for IoT: Turn this on to add an extra layer of threat protection to IoT and your devices. This option is not available for hubs in the free tier. For more information about this feature, see Microsoft Defender for IoT.
- Advanced Settings > Device-to-cloud partitions: This property relates the device-to-cloud messages to the number of simultaneous readers of the messages. Most hubs need only four partitions.
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.
Select Next: Review + create to review your choices. You see something similar to this screen, but with the values you selected when creating the hub.
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 device

If you completed the previous Quickstart: Send telemetry from a device to an IoT hub, you can skip this step.

A device must be registered with your IoT hub before it can connect. In this quickstart, you use the Azure Cloud Shell to register a simulated device.

Run the following command in Azure Cloud Shell to create the device identity.

YourIoTHubName: Replace this placeholder below with the name you chose for your IoT hub.

MyNodeDevice: This is the name of the device you're registering. It's recommended to use MyNodeDevice as shown. If you choose a different name for your device, you also need to use that name throughout this article, and update the device name in the sample applications before you run them.
```
az iot hub device-identity create \
  --hub-name {YourIoTHubName} --device-id MyNodeDevice
```
Run the following commands in Azure Cloud Shell to get the device connection string for the device you just registered:

YourIoTHubName: Replace this placeholder below with the name you chose for your IoT hub.
```
az iot hub device-identity connection-string show \
  --hub-name {YourIoTHubName} \
  --device-id MyNodeDevice \
  --output table
```
Make a note of the device connection string, which looks like:

HostName={YourIoTHubName}.azure-devices.net;DeviceId=MyNodeDevice;SharedAccessKey={YourSharedAccessKey}

You use this value later in the quickstart.
You also need a service connection string to enable the back-end application to connect to your IoT hub and retrieve the messages. The following command retrieves the service connection string for your IoT hub:

YourIoTHubName: Replace this placeholder below with the name you chose for your IoT hub.
```
az iot hub connection-string show \
  --policy-name service --name {YourIoTHubName} --output table
```
Make a note of the service connection string, which looks like:

HostName={YourIoTHubName}.azure-devices.net;SharedAccessKeyName=service;SharedAccessKey={YourSharedAccessKey}

You use this value later in the quickstart. This service connection string is different from the device connection string you noted in the previous step.

Listen for direct method calls

In a local terminal window, navigate to the root folder of the sample Node.js project. Then navigate to the iot-hub\Quickstarts\simulated-device-2 folder.
Open the SimulatedDevice.js file in a text editor of your choice.

Replace the value of the connectionString variable with the device connection string you made a note of earlier. Then save your changes to SimulatedDevice.js.
In the local terminal window, run the following commands to install the required libraries and run the simulated device application:
```
npm install
node SimulatedDevice.js
```
The following screenshot shows the output as the simulated device application sends telemetry to your IoT hub:

Call the direct method

In another local terminal window, navigate to the root folder of the sample Node.js project. Then navigate to the iot-hub\Quickstarts\back-end-application folder.
Open the BackEndApplication.js file in a text editor of your choice.

Replace the value of the connectionString variable with the service connection string you made a note of earlier. Then save your changes to BackEndApplication.js.
In the local terminal window, run the following commands to install the required libraries and run the back-end application:
```
npm install
node BackEndApplication.js
```
The following screenshot shows the output as the application makes a direct method call to the device and receives an acknowledgment:

After you run the back-end application, you see a message in the console window running the simulated device, and the rate at which it sends messages changes:

This quickstart uses two Python applications: a simulated device application that responds to direct methods called from a back-end application and a back-end application that calls the direct methods on the simulated device.

Prerequisites

An Azure account with an active subscription. Create one for free.
Python 3.7+. For other versions of Python supported, see Azure IoT Device Features.
A sample Python project from github. Download or clone the samples by using the Code button in the github repository.
Port 8883 open in your firewall. The device sample in this quickstart uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see Connecting to IoT Hub (MQTT).

Use the Bash environment in Azure Cloud Shell.
If you prefer, install the Azure CLI to run CLI reference commands.
- If you're using a local installation, sign in to the Azure CLI by using the az login command. To finish the authentication process, follow the steps displayed in your terminal. For additional sign-in options, see Sign in with the Azure CLI.
- When you're prompted, install Azure CLI extensions on first use. For more information about extensions, see Use extensions with the Azure CLI.
- Run az version to find the version and dependent libraries that are installed. To upgrade to the latest version, run az upgrade.

Note

Use az extension remove --name azure-cli-iot-ext to remove the legacy version of the extension.

Use az extension add --name azure-iot to add the new version of the extension.

To see what extensions you have installed, use az extension list.

Create an IoT hub

If you completed the previous Quickstart: Send telemetry from a device to an IoT hub, you can skip this step.

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

Sign in to the Azure portal.
From the Azure homepage, select the + Create a resource button, and then enter IoT Hub in the Search the Marketplace field.
Select IoT Hub from the search results, and then select Create.
On the Basics tab, complete the fields as follows:
- 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. To use an existing resource group, select that resource group. For more information, see Manage Azure Resource Manager resource groups.
- Region: Select the region in which you want your hub to be located. Select the location closest to you. 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.
- 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.
Important

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.
Select Next: Networking to continue creating your hub.

Choose the endpoints that devices can use to connect to your IoT Hub. You can select the default setting Public endpoint (all networks), or choose Public endpoint (selected IP ranges), or Private endpoint. Accept the default setting for this example.
Select Next: Management to continue creating your hub.

You can accept the default settings here. If desired, you can modify any of the following fields:
- Pricing and scale tier: Your selected 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 hub and up to 8,000 messages per day. Each Azure subscription can create one IoT hub in the free tier.
  
  If you are working through a Quickstart for IoT Hub device streams, select 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 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.
- Defender for IoT: Turn this on to add an extra layer of threat protection to IoT and your devices. This option is not available for hubs in the free tier. For more information about this feature, see Microsoft Defender for IoT.
- Advanced Settings > Device-to-cloud partitions: This property relates the device-to-cloud messages to the number of simultaneous readers of the messages. Most hubs need only four partitions.
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.
Select Next: Review + create to review your choices. You see something similar to this screen, but with the values you selected when creating the hub.
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 device

If you completed the previous Quickstart: Send telemetry from a device to an IoT hub, you can skip this step.

A device must be registered with your IoT hub before it can connect. In this quickstart, you use the Azure Cloud Shell to register a simulated device.

Run the following command in Azure Cloud Shell to create the device identity.

YourIoTHubName: Replace this placeholder below with the name you chose for your IoT hub.

MyPythonDevice: This is the name of the device you're registering. It's recommended to use MyPythonDevice as shown. If you choose a different name for your device, you also need to use that name throughout this article, and update the device name in the sample applications before you run them.
```
az iot hub device-identity create --hub-name {YourIoTHubName} --device-id MyPythonDevice
```
Run the following commands in Azure Cloud Shell to get the device connection string for the device you just registered:

YourIoTHubName: Replace this placeholder below with the name you chose for your IoT hub.
```
az iot hub device-identity connection-string show --hub-name {YourIoTHubName} --device-id MyPythonDevice --output table
```
Make a note of the device connection string, which looks like:

HostName={YourIoTHubName}.azure-devices.net;DeviceId=MyNodeDevice;SharedAccessKey={YourSharedAccessKey}

You use this value later in the quickstart.
You also need a service connection string to enable the back-end application to connect to your IoT hub and retrieve the messages. The following command retrieves the service connection string for your IoT hub:

YourIoTHubName: Replace this placeholder below with the name you choose for your IoT hub.
```
az iot hub connection-string show \
  --policy-name service \
  --hub-name {YourIoTHubName} \
  --output table
```
Make a note of the service connection string, which looks like:

HostName={YourIoTHubName}.azure-devices.net;SharedAccessKeyName=service;SharedAccessKey={YourSharedAccessKey}

You use this value later in the quickstart. This service connection string is different from the device connection string you noted in the previous step.

Listen for direct method calls

In a local terminal window, navigate to the root folder of the sample Python project. Then navigate to the iot-hub\Quickstarts\simulated-device-2 folder.
Open the SimulatedDevice.py file in a text editor of your choice.

Replace the value of the CONNECTION_STRING variable with the device connection string you made a note of earlier. Then save your changes to SimulatedDevice.py.
In the local terminal window, run the following commands to install the required libraries for the simulated device application:
```
pip install azure-iot-device
```
In the local terminal window, run the following commands to run the simulated device application:
```
python SimulatedDevice.py
```
The following screenshot shows the output as the simulated device application sends telemetry to your IoT hub:

Call the direct method

In another local terminal window, navigate to the root folder of the sample Python project. Then navigate to the iot-hub\Quickstarts\back-end-application folder.
Open the BackEndApplication.py file in a text editor of your choice.

Replace the value of the CONNECTION_STRING variable with the service connection string you made a note of earlier. Then save your changes to BackEndApplication.py.
In the local terminal window, run the following commands to install the required libraries for the simulated device application:
```
pip install azure-iot-hub
```
In the local terminal window, run the following commands to run the back-end application:
```
python BackEndApplication.py
```
The following screenshot shows the output as the application makes a direct method call to the device and receives an acknowledgment:

After you run the back-end application, you see a message in the console window running the simulated device, and the rate at which it sends messages changes:

Clean up resources

If you will be continuing to the next recommended article, you can keep the resources you've already created and reuse them.

Otherwise, you can delete the Azure resources created in this article to avoid charges.

Important

Deleting a resource group is irreversible. The resource group and all the resources contained in it are permanently deleted. Make sure that you do not accidentally delete the wrong resource group or resources. If you created the IoT Hub inside an existing resource group that contains resources you want to keep, only delete the IoT Hub resource itself instead of deleting the resource group.

To delete a resource group by name:

Sign in to the Azure portal and select Resource groups.
In the Filter by name textbox, type the name of the resource group containing your IoT Hub.
To the right of your resource group in the result list, select ... then Delete resource group.
You will be asked to confirm the deletion of the resource group. Type the name of your resource group again to confirm, and then select Delete. After a few moments, the resource group and all of its contained resources are deleted.

Next steps

In this quickstart, you called a direct method on a device from a service application, and responded to the direct method call in a simulated device application.

To learn how to route device-to-cloud messages to different destinations in the cloud, continue to the next tutorial.

Tutorial: Route telemetry to different endpoints for processing

Quickstart: Control a device connected to an IoT hub

Ocenite svoje iskustvo

Prerequisites

Create an IoT hub

Register a device

Retrieve the service connection string

Listen for direct method calls

Call the direct method

Prerequisites

Create an IoT hub

Register a device

Retrieve the service connection string

Listen for direct method calls

Call the direct method

Prerequisites

Create an IoT hub

Register a device

Listen for direct method calls

Call the direct method

Prerequisites

Create an IoT hub

Register a device

Listen for direct method calls

Call the direct method

Clean up resources

Next steps

Povratne informacije