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快速入门:将遥测数据从设备发送到 IoT 中心并使用后端应用程序读取该数据 (Python)Quickstart: Send telemetry from a device to an IoT hub and read it with a back-end application (Python)

IoT 中心是一项 Azure 服务,用于将大量遥测数据从 IoT 设备引入云中进行存储或处理。IoT Hub is an Azure service that enables you to ingest high volumes of telemetry from your IoT devices into the cloud for storage or processing. 本快速入门会将模拟设备应用程序的遥测数据通过 IoT 中心发送到后端应用程序进行处理。In this quickstart, you send telemetry from a simulated device application, through IoT Hub, to a back-end application for processing.

此快速入门使用预先编写的 Python 应用程序来发送遥测数据,使用 CLI 实用程序从中心读取遥测数据。The quickstart uses a pre-written Python application to send the telemetry and a CLI utility to read the telemetry from the hub. 运行这两个应用程序前,请先创建 IoT 中心并在中心注册设备。Before you run these two applications, you create an IoT hub and register a device with the hub.

使用 Azure Cloud ShellUse Azure Cloud Shell

Azure 托管 Azure Cloud Shell(一个可通过浏览器使用的交互式 shell 环境)。Azure hosts Azure Cloud Shell, an interactive shell environment that you can use through your browser. 通过 Cloud Shell 可以将 bashPowerShell 与 Azure 服务配合使用。Cloud Shell lets you use either bash or PowerShell to work with Azure services. 可以使用 Azure Cloud Shell 预安装的命令来运行本文中的代码,而不必在本地环境中安装任何内容。You can use the Cloud Shell pre-installed commands to run the code in this article without having to install anything on your local environment.

若要启动 Azure Cloud Shell,请执行以下操作:To launch Azure Cloud Shell:

选项Option 示例/链接Example/Link
选择代码块右上角的“试用”。 Select Try It in the upper-right corner of a code block. 选择“试用” 不会自动将代码复制到 Cloud Shell。Selecting Try It doesn't automatically copy the code to Cloud Shell. Azure Cloud Shell 的“试用”示例
转到 https://shell.azure.com 或选择“启动 Cloud Shell” 按钮可在浏览器中打开 Cloud Shell。Go to https://shell.azure.com or select the Launch Cloud Shell button to open Cloud Shell in your browser. 在新窗口中启动 Cloud ShellLaunch Cloud Shell in a new window
选择 Azure 门户右上方菜单栏中的“Cloud Shell” 按钮。Select the Cloud Shell button on the top-right menu bar in the Azure portal. Azure 门户中的“Cloud Shell”按钮

若要在 Azure Cloud Shell 中运行本文中的代码,请执行以下操作:To run the code in this article in Azure Cloud Shell:

  1. 启动 Cloud Shell。Launch Cloud Shell.
  2. 选择代码块上的“复制”按钮 以复制代码。Select the Copy button on a code block to copy the code.
  3. 在 Windows 和 Linux 上使用 Ctrl+Shift+V 将代码粘贴到 Cloud Shell 会话中,或在 macOS 上使用 Cmd+Shift+V 将代码粘贴到 Cloud Shell 会话中。Paste the code into the Cloud Shell session with Ctrl+Shift+V on Windows and Linux, or Cmd+Shift+V on macOS.
  4. Enter 运行此代码。Press Enter to run the code.

如果还没有 Azure 订阅,可以在开始前创建一个免费帐户If you don’t have an Azure subscription, create a free account before you begin.

先决条件Prerequisites

本快速入门中运行的示例应用程序是使用 Python 编写的。The sample application you run in this quickstart is written using Python. 目前,用于 Python 的 Microsoft Azure IoT SDK 仅支持每个平台的特定 Python 版本。Currently, the Microsoft Azure IoT SDKs for Python support only specific versions of Python for each platform. 若要了解详细信息,请参阅 Python SDK 自述文件To learn more, see the Python SDK Readme.

本快速入门假定你使用的是 Windows 开发计算机。This quickstart assumes you are using a Windows development machine. 对于 Windows 系统,仅支持 Python 3.6.xFor Windows systems, only Python 3.6.x is supported. 所选的 Python 安装程序应基于所使用的系统体系结构。The Python installer you choose should be based on the architecture of the system that you are working with. 如果系统 CPU 体系结构是 32 位,则下载 x86 安装程序;对于 64 位体系结构,则下载 x86-64 安装程序。If your system CPU architecture is 32 bit, then download the x86 installer; for the 64-bit architecture, download the x86-64 installer. 此外,请确保为你的体系结构(x86 或 x64)安装了 Microsoft Visual C++ Redistributable for Visual Studio 2019Additionally, make sure the Microsoft Visual C++ Redistributable for Visual Studio 2019 is installed for your architecture (x86 or x64).

可以从 Python.org 为其他平台下载 Python。You can download Python for other platforms from Python.org.

可以使用以下命令之一验证开发计算机上 Python 的当前版本:You can verify the current version of Python on your development machine using one of the following commands:

python - -version
python3 - -version

运行以下命令将用于 Azure CLI 的 Microsoft Azure IoT 扩展添加到 Cloud Shell 实例。Run the following command to add the Microsoft Azure IoT Extension for Azure CLI to your Cloud Shell instance. IOT 扩展会将 IoT 中心、IoT Edge 和 IoT 设备预配服务 (DPS) 特定的命令添加到 Azure CLI。The IOT Extension adds IoT Hub, IoT Edge, and IoT Device Provisioning Service (DPS) specific commands to Azure CLI.

az extension add --name azure-cli-iot-ext

https://github.com/Azure-Samples/azure-iot-samples-python/archive/master.zip 下载示例 Python 项目并提取 ZIP 存档。Download the sample Python project from https://github.com/Azure-Samples/azure-iot-samples-python/archive/master.zip and extract the ZIP archive.

创建 IoT 中心Create an IoT hub

此部分介绍如何使用 Azure 门户创建 IoT 中心。This section describes how to create an IoT hub using the Azure portal.

  1. 登录到 Azure 门户Sign in to the Azure portal.

  2. 选择“创建资源”,然后在“搜索市场”字段中输入“IoT 中心”。 Choose Create a resource, and then enter IoT Hub in the Search the Marketplace field.

  3. 在搜索结果中选择“IoT 中心”,然后选择“创建” 。Select IoT Hub from the search results, and then select Create.

  4. 在“基本信息”选项卡上,按如下所示填写字段: On the Basics tab, complete the fields as follows:

    • 订阅:选择要用于中心的订阅。Subscription: Select the subscription to use for your hub.

    • 资源组:选择一个资源组或新建一个资源组。Resource Group: Select a resource group or create a new one. 若要新建资源组,请选择“新建”并填写要使用的名称。 To create a new one, select Create new and fill in the name you want to use. 若要使用现有的资源组,请选择它。To use an existing resource group, select that resource group. 有关详细信息,请参阅管理 Azure 资源管理器资源组For more information, see Manage Azure Resource Manager resource groups.

    • 区域:选择中心所在的区域。Region: Select the region in which you want your hub to be located. 选择最靠近你的位置。Select the location closest to you.

    • IoT 中心名称:输入中心的名称。IoT Hub Name: Enter a name for your hub. 该名称必须全局唯一。This name must be globally unique. 如果输入的名称可用,会显示一个绿色复选标记。If the name you enter is available, a green check mark appears.

    重要

    由于 IoT 中心将作为 DNS 终结点公开可发现,因此请务必避免在命名它时输入任何敏感信息或个人身份信息。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.

    在 Azure 门户中创建中心

  5. 在完成时选择“下一步: 大小和规模”,以继续创建中心。Select Next: Size and scale to continue creating your hub.

    使用 Azure 门户为新的中心设置大小和规模

    在此屏幕中可以设置以下值:This screen allows you to set the following values:

    • 定价和缩放层:选择的层。Pricing and scale tier: Your selected tier. 可以根据你需要的功能数以及每天通过解决方案发送的消息数从多个层中进行选择。You can choose from several tiers depending on how many features you want and how many messages you send through your solution per day. 免费层适用于测试和评估。The free tier is intended for testing and evaluation. 允许 500 台设备连接到中心,每天最多可传输 8,000 条消息。It allows 500 devices to be connected to the hub and up to 8,000 messages per day. 每个 Azure 订阅可以在免费层中创建一个 IoT 中心。Each Azure subscription can create one IoT Hub in the free tier.

    • IoT 中心单元:每日每单位允许的消息数取决于中心的定价层。IoT Hub units: The number of messages allowed per unit per day depends on your hub's pricing tier. 例如,如果希望中心支持 700,000 条消息引入,请选择两个 S1 层单位。For example, if you want the hub to support ingress of 700,000 messages, you choose two S1 tier units. 有关其他层选项的详细信息,请参阅选择合适的 IoT 中心层For details about the other tier options, see Choosing the right IoT Hub tier.

    • 高级 > 设备到云的分区:此属性将设备到云消息与这些消息的同步读取器数目相关联。Advanced > Device-to-cloud partitions: This property relates the device-to-cloud messages to the number of simultaneous readers of the messages. 大多数中心只需要 4 个分区。Most hubs only need four partitions.

  6. 对于本教程,请接受默认选项,然后选择“查看 + 创建”以查看所做的选择。 For this tutorial, accept the default choices, and then select Review + create to review your choices. 会显示类似于以下的屏幕。You see something similar to this screen.

    查看用于创建新中心的信息

  7. 选择“创建”以创建新的中心 。Select Create to create your new hub. 创建中心需要几分钟时间。Creating the hub takes a few minutes.

注册设备Register a device

必须先将设备注册到 IoT 中心,然后该设备才能进行连接。A device must be registered with your IoT hub before it can connect. 在本快速入门中,将使用 Azure Cloud Shell 来注册模拟设备。In this quickstart, you use the Azure Cloud Shell to register a simulated device.

  1. 在 Azure Cloud Shell 中运行以下命令,以创建设备标识。Run the following command in Azure Cloud Shell to create the device identity.

    YourIoTHubName:将下面的占位符替换为你为 IoT 中心选择的名称。YourIoTHubName: Replace this placeholder below with the name you choose for your IoT hub.

    MyPythonDevice:这是为注册的设备提供的名称。MyPythonDevice: This is the name given for the registered device. 请按显示的方法使用 MyPythonDevice。Use MyPythonDevice as shown. 如果为设备选择不同名称,则可能还需要在本文中从头至尾使用该名称,并在运行示例应用程序之前在其中更新设备名称。If you choose a different name for your device, you will 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
    
  2. 在 Azure Cloud Shell 中运行以下命令,以获取已注册设备的_设备连接字符串_:Run the following commands in Azure Cloud Shell to get the device connection string for the device you registered:

    YourIoTHubName:将下面的占位符替换为你为 IoT 中心选择的名称。YourIoTHubName: Replace this placeholder below with the name you choose for your IoT hub.

    az iot hub device-identity show-connection-string --hub-name YourIoTHubName --device-id MyPythonDevice --output table
    

    记下如下所示的设备连接字符串:Make a note of the device connection string, which looks like:

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

    稍后会在快速入门中用到此值。You use this value later in the quickstart.

发送模拟遥测数据Send simulated telemetry

模拟设备应用程序会连接到 IoT 中心上特定于设备的终结点,并发送模拟的温度和湿度遥测数据。The simulated device application connects to a device-specific endpoint on your IoT hub and sends simulated temperature and humidity telemetry.

  1. 在本地终端窗口中,导航到示例 Python 项目的根文件夹。In a local terminal window, navigate to the root folder of the sample Python project. 然后导航到 iot-hub\Quickstarts\simulated-device 文件夹。Then navigate to the iot-hub\Quickstarts\simulated-device folder.

  2. 在所选文本编辑器中打开 SimulatedDevice.py 文件 。Open the SimulatedDevice.py file in a text editor of your choice.

    CONNECTION_STRING 变量的值替换为之前记下的设备连接字符串。Replace the value of the CONNECTION_STRING variable with the device connection string you made a note of previously. 然后将更改保存到 SimulatedDevice.py 文件 。Then save your changes to SimulatedDevice.py file.

  3. 在本地终端窗口中,运行以下命令,为模拟设备应用程序安装所需的库:In the local terminal window, run the following commands to install the required libraries for the simulated device application:

    pip install azure-iothub-device-client
    
  4. 在本地终端窗口中,运行以下命令,以便运行模拟设备应用程序:In the local terminal window, run the following commands to run the simulated device application:

    python SimulatedDevice.py
    

    以下屏幕截图显示了模拟设备应用程序将遥测数据发送到 IoT 中心后的输出:The following screenshot shows the output as the simulated device application sends telemetry to your IoT hub:

    运行模拟设备

避免导入 iothub_client 错误To avoid the import iothub_client error

当前版本的适用于 Python 的 Azure IoT SDK 是我们的 C SDK 的包装器。The current version of the Azure IoT SDK for Python is a wrapper over our C SDK. 它是使用 Boost 库生成的。It is generated using the Boost library. 因此,它有几个重要限制。Because of that, it comes with several significant limitations. 有关更多详细信息,请参阅此处See more details here

  1. 检查是否有正确版本的 PythonCheck that you have the right version of Python. 请注意,只有某些版本适用于此示例。Be aware that only certain versions works fine for this sample.
  2. 检查是否有正确版本的 C++ 运行时 Microsoft Visual C++ Redistributable for Visual Studio 2019Check that you have the right version of C++ runtime Microsoft Visual C++ Redistributable for Visual Studio 2019. (我们建议使用最新版本)。(We recommend the latest).
  3. 验证是否已安装 iothub 客户端:pip install azure-iothub-device-clientVerify that you have installed the iothub client: pip install azure-iothub-device-client.

从中心读取遥测数据Read the telemetry from your hub

IoT 中心 CLI 扩展可以连接到 IoT 中心上的服务端事件终结点。The IoT Hub CLI extension can connect to the service-side Events endpoint on your IoT Hub. 该扩展会接收模拟设备发送的设备到云的消息。The extension receives the device-to-cloud messages sent from your simulated device. IoT 中心后端应用程序通常在云中运行,接收和处理设备到云的消息。An IoT Hub back-end application typically runs in the cloud to receive and process device-to-cloud messages.

在 Azure Cloud Shell 中运行以下命令,并将 YourIoTHubName 替换为 IoT 中心的名称:Run the following commands in Azure Cloud Shell, replacing YourIoTHubName with the name of your IoT hub:

az iot hub monitor-events --hub-name YourIoTHubName --device-id MyPythonDevice 

以下屏幕截图显示了在扩展接收模拟设备发送到 IoT 中心的遥测数据后的输出:The following screenshot shows the output as the extension receives telemetry sent by the simulated device to the hub:

运行后端应用程序

清理资源Clean up resources

如果想要继续学习下一篇建议的文章,可以保留已创建的资源,以便重复使用。If you will be continuing to the next recommended article, you can keep the resources you've already created and reuse them.

否则,可删除本文中创建的 Azure 资源,避免收费。Otherwise, you can delete the Azure resources created in this article to avoid charges.

重要

删除资源组的操作不可逆。Deleting a resource group is irreversible. 资源组以及包含在其中的所有资源将被永久删除。The resource group and all the resources contained in it are permanently deleted. 请确保不会意外删除错误的资源组或资源。Make sure that you do not accidentally delete the wrong resource group or resources. 如果在现有的包含要保留资源的资源组中创建了 IoT 中心,则只删除 IoT 中心资源本身,而不要删除资源组。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.

若要按名称删除资源组,请执行以下操作:To delete a resource group by name:

  1. 登录到 Azure 门户,并单击“资源组”。 Sign in to the Azure portal and click Resource groups.

  2. 在“按名称筛选...”文本框中键入包含 IoT 中心的资源组的名称 。In the Filter by name... textbox, type the name of the resource group containing your IoT Hub.

  3. 在结果列表中的资源组右侧,单击“...”,然后单击“删除资源组” 。To the right of your resource group in the result list, click ... then Delete resource group.

    删除

  4. 系统会要求确认是否删除资源组。You will be asked to confirm the deletion of the resource group. 再次键入资源组的名称进行确认,然后单击“删除” 。Type the name of your resource group again to confirm, and then click Delete. 片刻之后,将会删除该资源组及其包含的所有资源。After a few moments, the resource group and all of its contained resources are deleted.

后续步骤Next steps

在本快速入门中,已设置 IoT 中心、注册设备、使用 Python 应用程序发送模拟遥测数据到中心并使用简单的后端应用程序读取中心的遥测数据。In this quickstart, you've setup an IoT hub, registered a device, sent simulated telemetry to the hub using a Python application, and read the telemetry from the hub using a simple back-end application.

若要了解如何从后端应用程序控制模拟设备,请继续阅读下一快速入门教程。To learn how to control your simulated device from a back-end application, continue to the next quickstart.