通過IoT中心將環(huán)境數(shù)據(jù)從ProjectLab發(fā)送到Azure

IotHubManager.cs

public class IotHubManager
{
    private const string HubName = Secrets.HUB_NAME;
    private const string SasToken = Secrets.SAS_TOKEN;
    private const string DeviceId = Secrets.DEVICE_ID;

    private Connection connection;
    private SenderLink sender;

    public IotHubManager() { }

    public async Task Initialize()
    {
        string hostName = HubName + ".azure-devices.net";
        string userName = DeviceId + "@sas." + HubName;
        string senderAddress = "devices/" + DeviceId + "/messages/events";

        Resolver.Log.Info("Create connection factory...");
        var factory = new ConnectionFactory();

        Resolver.Log.Info("Create connection ...");
        connection = await factory.CreateAsync(new Address(hostName, 5671, userName, SasToken));

        Resolver.Log.Info("Create session ...");
        var session = new Session(connection);

        Resolver.Log.Info("Create SenderLink ...");
        sender = new SenderLink(session, "send-link", senderAddress);
    }

    public Task SendEnvironmentalReading((Temperature? Temperature, RelativeHumidity? Humidity, Pressure? Pressure, Resistance? GasResistance) reading)
    {
        try
        {
            Resolver.Log.Info("Create payload");
            string messagePayload = $"{{"Temperature":{reading.Temperature.Value.Celsius}," +
                $""Humidity":{reading.Humidity.Value.Percent}," +
                $""Pressure":{reading.Pressure.Value.Millibar}}}";

            Resolver.Log.Info("Create message");
            var message = new Message(Encoding.UTF8.GetBytes(messagePayload));
            message.ApplicationProperties = new Amqp.Framing.ApplicationProperties();

            Resolver.Log.Info("Send message");
            sender.Send(message, null, null);

            Resolver.Log.Info($"*** DATA SENT - Temperature - {reading.Temperature.Value.Celsius}, Humidity - {reading.Humidity.Value.Percent}, Pressure - {reading.Pressure.Value.Millibar} ***");
        }
        catch (Exception ex)
        {
            Resolver.Log.Info($"-- D2C Error - {ex.Message} --");
        }

        return Task.CompletedTask;
    }
}

此類用于與 Azure IoT 中心建立連接并通過 HTU21D 傳感器發(fā)送環(huán)境讀數(shù)。

DisplayController.cs

public class DisplayController
{
    private static readonly Lazy instance =
        new Lazy(() => new DisplayController());
    public static DisplayController Instance => instance.Value;

    static Color backgroundColor = Color.FromHex("#23ABE3");
    static Color foregroundColor = Color.Black;

    CancellationTokenSource token;

    protected BufferRgb888 imgConnecting, imgConnected, imgRefreshing, imgRefreshed;
    protected MicroGraphics graphics;

    private DisplayController() { }

    public void Initialize(IGraphicsDisplay display)
    {
        imgConnected = LoadJpeg("img_wifi_connected.jpg");
        imgConnecting = LoadJpeg("img_wifi_connecting.jpg");
        imgRefreshing = LoadJpeg("img_refreshing.jpg");
        imgRefreshed = LoadJpeg("img_refreshed.jpg");

        graphics = new MicroGraphics(display)
        {
            CurrentFont = new Font12x16(),
            Stroke = 3,
        };

        graphics.Clear(true);
    }

    BufferRgb888 LoadJpeg(string fileName)
    {
        var jpgData = LoadResource(fileName);
        var decoder = new JpegDecoder();
        decoder.DecodeJpeg(jpgData);
        return new BufferRgb888(decoder.Width, decoder.Height, decoder.GetImageData());
    }

    protected void DrawBackground()
    {
        var logo = LoadJpeg("img_meadow.jpg");

        graphics.Clear(backgroundColor);

        graphics.DrawBuffer(
            x: graphics.Width / 2 - logo.Width / 2,
            y: 63,
            buffer: logo);

        graphics.DrawText(graphics.Width / 2, 160, "Azure IoT Hub", Color.Black, alignmentH: HorizontalAlignment.Center);
    }

    protected byte[] LoadResource(string filename)
    {
        var assembly = Assembly.GetExecutingAssembly();
        var resourceName = $"MeadowAzureIoTHub.{filename}";

        using Stream stream = assembly.GetManifestResourceStream(resourceName);
        using var ms = new MemoryStream();
        stream.CopyTo(ms);
        return ms.ToArray();
    }

    public void ShowSplashScreen()
    {
        DrawBackground();

        graphics.Show();
    }

    public async Task ShowConnectingAnimation()
    {
        token = new CancellationTokenSource();

        bool alternateImg = false;
        while (!token.IsCancellationRequested)
        {
            alternateImg = !alternateImg;

            graphics.DrawBuffer(204, 6, alternateImg ? imgConnecting : imgConnected);
            graphics.Show();

            await Task.Delay(500);
        }
    }

    public void ShowConnected()
    {
        token.Cancel();
        graphics.DrawBuffer(204, 6, imgConnected);

        graphics.DrawBuffer(6, 6, imgRefreshed);

        graphics.DrawRectangle(0, 32, 240, 208, backgroundColor, true);

        graphics.DrawCircle(120, 75, 50, foregroundColor);
        graphics.DrawText(120, 59, "Temp", foregroundColor, alignmentH: HorizontalAlignment.Center);

        graphics.DrawCircle(62, 177, 50, foregroundColor);
        graphics.DrawText(62, 161, "Pres", foregroundColor, alignmentH: HorizontalAlignment.Center);

        graphics.DrawCircle(178, 177, 50, foregroundColor);
        graphics.DrawText(178, 161, "Hum", foregroundColor, alignmentH: HorizontalAlignment.Center);

        graphics.Show();
    }

    public async Task StartSyncCompletedAnimation((Temperature? Temperature, RelativeHumidity? Humidity, Pressure? Pressure, Resistance? GasResistance) reading)
    {
        graphics.DrawBuffer(6, 6, imgRefreshing);
        graphics.Show();
        await Task.Delay(TimeSpan.FromSeconds(1));

        graphics.DrawRectangle(75, 78, 90, 16, backgroundColor, true);
        graphics.DrawText(120, 78, $"{reading.Temperature.Value.Celsius:N1}°C", foregroundColor, alignmentH: HorizontalAlignment.Center);

        graphics.DrawRectangle(17, 180, 90, 16, backgroundColor, true);
        graphics.DrawText(62, 180, $"{reading.Pressure.Value.StandardAtmosphere:N1}atm", foregroundColor, alignmentH: HorizontalAlignment.Center);

        graphics.DrawRectangle(133, 180, 90, 16, backgroundColor, true);
        graphics.DrawText(178, 180, $"{reading.Humidity.Value.Percent:N2}%", foregroundColor, alignmentH: HorizontalAlignment.Center);

        graphics.DrawBuffer(6, 6, imgRefreshed);
        graphics.Show();
    }
}

此類使用MicroGraphics在 ST7789 顯示屏中繪制所有 UI，例如在應(yīng)用程序啟動時顯示啟動畫面、更新溫度/濕度值，以及 WiFi 和同步指示器以了解消息何時發(fā)送到 IoT 中心。

MeadowApp.cs

public class MeadowApp : App
{
    RgbPwmLed onboardLed;
    IProjectLabHardware projectLab;
    IotHubManager amqpController;

    public override Task Initialize()
    {
        onboardLed = new RgbPwmLed(
            Device.Pins.OnboardLedRed,
            Device.Pins.OnboardLedGreen,
            Device.Pins.OnboardLedBlue);
        onboardLed.SetColor(Color.Red);

        try
        {
            amqpController = new IotHubManager();

            var wifi = Device.NetworkAdapters.Primary();
            wifi.NetworkConnected += NetworkConnected;

            projectLab = ProjectLab.Create();
            projectLab.EnvironmentalSensor.Updated += EnvironmentalSensorUpdated;

            DisplayController.Instance.Initialize(projectLab.Display);
            DisplayController.Instance.ShowSplashScreen();
            DisplayController.Instance.ShowConnectingAnimation();
        }
        catch (Exception ex)
        {
            Resolver.Log.Error($"Failed to Connect: {ex.Message}");
        }

        return Task.CompletedTask;
    }

    private async void NetworkConnected(INetworkAdapter sender, NetworkConnectionEventArgs args)
    {
        DisplayController.Instance.ShowConnected();

        await amqpController.Initialize();

        projectLab.EnvironmentalSensor.StartUpdating(TimeSpan.FromSeconds(15));

        onboardLed.SetColor(Color.Green);
    }

    private async void EnvironmentalSensorUpdated(object sender, IChangeResult<(Meadow.Units.Temperature? Temperature, Meadow.Units.RelativeHumidity? Humidity, Meadow.Units.Pressure? Pressure, Meadow.Units.Resistance? GasResistance)> e)
    {
        await amqpController.SendEnvironmentalReading(e.New);
        await DisplayController.Instance.StartSyncCompletedAnimation(e.New);
    }
}

MeadowApp主類初始化 ProjectLab 上的顯示和環(huán)境傳感器，一旦 Meadow 加入 WiFi 網(wǎng)絡(luò)并與 Azure 建立連接，它將開始每 15 秒讀取一次室溫、濕度和壓力。

第 5 步 - 運行項目

單擊Visual Studio中的“運行”按鈕。它應(yīng)該類似于以下 GIF：

當應(yīng)用程序運行時，您應(yīng)該有類似這樣的輸出：

Create connection factory...
Create connection ...
Create session ...
Create SenderLink ...
Create payload
Create message
Send message
*** DATA SENT - Temperature - 27.9073605400976, Humidity - 29.4871487326418, Pressure - 1020.90879412913 ***
Create payload
Create message
Send message
*** DATA SENT - Temperature - 28.0586979364511, Humidity - 29.1871445300884, Pressure - 1020.8916192437 ***
Create payload
Create message
Send message
*** DATA SENT - Temperature - 28.179768034583, Humidity - 28.9781536413303, Pressure - 1020.90573418024 ***
...

這可確保您已建立與Azure的連接，并且該應(yīng)用每 15 秒向IoT 中心發(fā)送一次數(shù)據(jù)。

您還可以轉(zhuǎn)到Azure門戶，打開IoT 中心概述部分，然后查看傳入消息的數(shù)量隨著時間的推移而增加。

?

IoT 中心傳入消息

?

查看 Meadow.Foundation！

就您可以使用 Meadow.Foundation 做的大量令人興奮的事情而言，這個項目只是冰山一角。

它帶有一個龐大的外設(shè)驅(qū)動程序庫，其中包含適用于最常見傳感器和外設(shè)的驅(qū)動程序。

• 它帶有一個龐大的外設(shè)驅(qū)動程序庫，其中包含適用于最常見傳感器和外設(shè)的驅(qū)動程序。
• 外設(shè)驅(qū)動程序封裝了核心邏輯并公開了一個簡單、干凈、現(xiàn)代的 API。
• 該項目得到了不斷發(fā)展的社區(qū)的支持，該社區(qū)不斷致力于構(gòu)建酷炫的互聯(lián)事物，并且總是樂于幫助新來者和討論新項目。

參考

• 草地向?qū)?/font>
• 草地基金會
• Meadow.Foundation.Displays.St7789 API
• Meadow.Foundation.Sensors.Atmospheric.Htu21d API
• 為您的 Meadow 項目設(shè)置 Azure IoT 中心