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 (Node.js)Quickstart: Send telemetry from a device to an IoT hub and read it with a back-end application (Node.js)

本快速入门会将模拟设备应用程序的遥测数据通过 Azure 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 Azure IoT Hub to a back-end application for processing. 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. 本快速入门使用两个预先编写的 Node.js 应用程序:一个用于发送遥测数据,一个用于读取中心的遥测数据。This quickstart uses two pre-written Node.js applications: one to send the telemetry and one 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.

先决条件Prerequisites

  • 具有活动订阅的 Azure 帐户。An Azure account with an active subscription. 创建试用帐户Create trial.

  • Node.js 10+Node.js 10+.

  • 一个示例 Node.js 项目A sample Node.js project.

  • 端口 8883 在防火墙中处于打开状态。Port 8883 open in your firewall. 本快速入门中的设备示例使用 MQTT 协议,该协议通过端口 8883 进行通信。The device sample in this quickstart uses MQTT protocol, which communicates over port 8883. 在某些公司和教育网络环境中,此端口可能被阻止。This port may be blocked in some corporate and educational network environments. 有关解决此问题的更多信息和方法,请参阅连接到 IoT 中心(MQTT)For more information and ways to work around this issue, see Connecting to IoT Hub (MQTT).

可以使用以下命令验证开发计算机上 Node.js 当前的版本:You can verify the current version of Node.js on your development machine using the following command:

node --version

添加 Azure IoT 扩展Add Azure IoT Extension

运行以下命令将用于 Azure CLI 的 Azure IoT 扩展添加。Run the following command to add the Azure IoT Extension for Azure CLI. 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

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. 从 Azure 主页中选择“+ 创建资源”按钮,然后在“搜索市场”字段中输入“IoT 中心”。 From the Azure homepage, select the + Create a resource button, 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. 此名称必须全局唯一。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

    IoT 中心将公开为 DNS 终结点,因此,命名时请务必避免包含任何敏感信息。The IoT hub will be publicly discoverable as a DNS endpoint, so make sure to avoid any sensitive information while naming 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级中进行选择。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:每个单位每日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.

    • 高级设置 > 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 Settings > 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 need only four partitions.

  6. 对于本文,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 article, 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,请使用 Azure CLI 来注册模拟设备。In this quickstart, you use the Azure CLI to register a simulated device.

  1. 运行以下命令,以创建设备标识。Run the following command 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 chose for your IoT hub.

    MyNodeDevice:这是所注册的设备的名称。MyNodeDevice: This is the name of the device you're registering. 建议使用 MyNodeDevice,如图所示。It's recommended to use MyNodeDevice 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'll 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
    
  2. 运行以下命令,获取刚注册设备的设备连接字符串: Run the following command to get the device connection string for the device you just 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 chose for your IoT hub.

    az iot hub device-identity show-connection-string --hub-name {YourIoTHubName} --device-id MyNodeDevice --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.cn;DeviceId=MyNodeDevice;SharedAccessKey={YourSharedAccessKey}

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

  3. 还需一个服务连接字符串,以便后端应用程序能够连接到 IoT 中心并检索消息 。You also need a service connection string to enable the back-end application to connect to your IoT hub and retrieve the messages. 以下命令检索 IoT 中心的服务连接字符串:The following command retrieves the service connection string for your IoT hub:

    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 chose for your IoT hub.

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

    记下如下所示的服务连接字符串:Make a note of the service connection string, which looks like:

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

    稍后会在快速入门中用到此值。You'll use this value later in the quickstart. 此服务连接字符串与你在上一步中记录的设备连接字符串不同。This service connection string is different from the device connection string you noted in the previous step.

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. 打开本地终端窗口,导航到示例 Node.js 项目的根文件夹。Open your local terminal window, navigate to the root folder of the sample Node.js 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.js 文件 。Open the SimulatedDevice.js file in a text editor of your choice.

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

  3. 在本地终端窗口中,运行以下命令以安装所需的库,并运行模拟设备应用程序: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
    

    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

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

后端应用程序会连接到 IoT 中心上的服务端“事件”终结点 。The back-end application connects to the service-side Events endpoint on your IoT Hub. 应用程序会接收模拟设备发送的设备到云的消息。The application 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.

  1. 打开另一个本地终端窗口,导航到示例 Node.js 项目的根文件夹。Open another local terminal window, navigate to the root folder of the sample Node.js project. 然后导航到 iot-hub\Quickstarts\read-d2c-messages 文件夹 。Then navigate to the iot-hub\Quickstarts\read-d2c-messages folder.

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

    connectionString 变量的值替换为以前记下的服务连接字符串。Replace the value of the connectionString variable with the service connection string you made a note of earlier. 然后将更改保存到 ReadDeviceToCloudMessages.jsThen save your changes to ReadDeviceToCloudMessages.js.

  3. 在本地终端窗口中运行以下命令,以安装所需的库并运行后端应用程序:In the local terminal window, run the following commands to install the required libraries and run the back-end application:

    npm install
    node ReadDeviceToCloudMessages.js
    

    以下屏幕截图显示了后端应用程序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 back-end application 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,然后选择“资源组”。 Sign in to the Azure portal and select 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,选择“...”,然后选择“删除资源组” 。To the right of your resource group in the result list, select ... then Delete resource group.

    Delete

  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,然后选择“删除” 。Type the name of your resource group again to confirm, and then select 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

本快速入门设置了 IoT 中心、注册了设备、使用 Node.js 应用程序发送了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 set up an IoT hub, registered a device, sent simulated telemetry to the hub using a Node.js 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.