描述

（項目更新為RC-3（2023年3月30日發(fā)布）

這個項目是對我們令人敬畏的由草地驅(qū)動的快速原型制作板Project Lab的介紹。在本指南中，我們將向您展示如何將它與它自己的 NuGet 包一起使用，該包封裝了所有外圍設(shè)備的接線，讓您可以立即專注于構(gòu)建您的 IoT Meadow 解決方案。

在您開始這個項目之前，請確保您的 Meadow 板和開發(fā)環(huán)境是完全最新的。檢查發(fā)行說明部分以仔細檢查。

第 1 步 - 創(chuàng)建 Meadow 應(yīng)用程序項目

在 Visual Studio 2022 for Windows或macOS中創(chuàng)建一個新的Meadow Application項目并將其命名為ProjLab_Demo 。

第 2 步 - 添加所需的 NuGet 包

對于這個項目，搜索并安裝以下 NuGet 包：

• 草地項目實驗室

第 3 步 - 編寫 ProjLab_Demo 的代碼

顯示控制器.cs

復(fù)制下面的代碼：

public class DisplayController
{
    readonly MicroGraphics graphics;

    public (Temperature? Temperature, RelativeHumidity? Humidity, Pressure? Pressure, Resistance? GasResistance)? AtmosphericConditions
    {
        get => atmosphericConditions;
        set
        {
            atmosphericConditions = value;
            Update();
        }
    }
    (Temperature? Temperature, RelativeHumidity? Humidity, Pressure? Pressure, Resistance? GasResistance)? atmosphericConditions;

    public Illuminance? LightConditions
    {
        get => lightConditions;
        set
        {
            lightConditions = value;
            Update();
        }
    }
    Illuminance? lightConditions;

    public (Acceleration3D? Acceleration3D, AngularVelocity3D? AngularVelocity3D, Temperature? Temperature) AccelerationConditions
    {
        get => accelerationConditions;
        set
        {
            accelerationConditions = value;
            Update();
        }
    }
    (Acceleration3D? Acceleration3D, AngularVelocity3D? AngularVelocity3D, Temperature? Temperature) accelerationConditions;


    public bool UpButtonState
    {
        get => upButtonState;
        set
        {
            upButtonState = value;
            Update();
        }
    }
    bool upButtonState = false;

    public bool DownButtonState
    {
        get => downButtonState;
        set
        {
            downButtonState = value;
            Update();
        }
    }
    bool downButtonState = false;

    public bool LeftButtonState
    {
        get => leftButtonState;
        set
        {
            leftButtonState = value;
            Update();
        }
    }
    bool leftButtonState = false;

    public bool RightButtonState
    {
        get => rightButtonState;
        set
        {
            rightButtonState = value;
            Update();
        }
    }
    bool rightButtonState = false;

    bool isUpdating = false;
    bool needsUpdate = false;

    public DisplayController(IGraphicsDisplay display)
    {
        graphics = new MicroGraphics(display)
        {
            CurrentFont = new Font12x16()
        };

        graphics.Clear(true);
    }

    public void Update()
    {
        if (isUpdating)
        {   //queue up the next update
            needsUpdate = true;
            return;
        }

        isUpdating = true;

        graphics.Clear();
        Draw();
        graphics.Show();

        isUpdating = false;

        if (needsUpdate)
        {
            needsUpdate = false;
            Update();
        }
    }

    void DrawStatus(string label, string value, Color color, int yPosition)
    {
        graphics.DrawText(x: 2, y: yPosition, label, color: color);
        graphics.DrawText(x: 238, y: yPosition, value, alignmentH: HorizontalAlignment.Right, color: color);
    }

    void Draw()
    {
        graphics.DrawText(x: 2, y: 0, "Hello PROJ LAB!", WildernessLabsColors.AzureBlue);

        if (AtmosphericConditions is { } conditions)
        {
            if (conditions.Temperature is { } temp)
            {
                DrawStatus("Temperature:", $"{temp.Celsius:N1}C", WildernessLabsColors.GalleryWhite, 35);
            }

            if (conditions.Pressure is { } pressure)
            {
                DrawStatus("Pressure:", $"{pressure.StandardAtmosphere:N1}atm", WildernessLabsColors.GalleryWhite, 55);
            }

            if (conditions.Humidity is { } humidity)
            {
                DrawStatus("Humidity:", $"{humidity.Percent:N1}%", WildernessLabsColors.GalleryWhite, 75);
            }
        }

        if (LightConditions is { } light)
        {
            DrawStatus("Lux:", $"{light:N0}Lux", WildernessLabsColors.GalleryWhite, 95);
        }

        if (AccelerationConditions is { } acceleration)
        {
            if (acceleration.Acceleration3D is { } accel3D)
            {
                DrawStatus("Accel:", $"{accel3D.X.Gravity:0.#},{accel3D.Y.Gravity:0.#},{accel3D.Z.Gravity:0.#}g", WildernessLabsColors.AzureBlue, 115);
            }

            if (acceleration.AngularVelocity3D is { } angular3D)
            {
                DrawStatus("Gyro:", $"{angular3D.X:0},{angular3D.Y:0},{angular3D.Z:0}rpm", WildernessLabsColors.AzureBlue, 135);
            }
        }

        DrawStatus("Left:", $"{(LeftButtonState ? "pressed" : "released")}", WildernessLabsColors.ChileanFire, 200);
        DrawStatus("Down:", $"{(DownButtonState ? "pressed" : "released")}", WildernessLabsColors.ChileanFire, 180);
        DrawStatus("Up:", $"{(UpButtonState ? "pressed" : "released")}", WildernessLabsColors.ChileanFire, 160);
        DrawStatus("Right:", $"{(RightButtonState ? "pressed" : "released")}", WildernessLabsColors.ChileanFire, 220);
    }
}

此類的目的是控制來自 Project Lab 板載外圍設(shè)備的信息并將其顯示到其 240x240 顯示器中，使用MicroGraphics. 我們有以下屬性：

• AtmosphericConditions- 該元組存儲BME688大氣傳感器返回的值，能夠測量溫度、濕度、壓力和氣體阻力。
• LightConditions- 存儲來自BH1750光傳感器的照度值。
• AccelerationConditions- 另一個存儲BMI270傳感器給出的 3D 加速度、3D 角速度甚至溫度的元組。
• UpButtonState- 存儲向上按鈕狀態(tài)的布爾值。
• DownButtonState- 存儲向下按鈕狀態(tài)的布爾值。
• LeftButtonState- 存儲左鍵狀態(tài)的布爾值。
• RightButtonState- 存儲右按鈕狀態(tài)的布爾值。

請注意，在所有這些屬性的設(shè)置器中，它將調(diào)用Update()將運行邏輯以使用MicroGraphics 更新顯示器上的值的方法。

MeadowApp.cs

復(fù)制下面的代碼：

// Change F7FeatherV2 to F7FeatherV1 for V1.x boards
public class MeadowApp : App
{
    DisplayController displayController;
    RgbPwmLed onboardLed;
    IProjectLabHardware projLab;

    public override Task Initialize()
    {
        Resolver.Log.Loglevel = Meadow.Logging.LogLevel.Trace;

        Resolver.Log.Info("Initialize hardware...");

        //==== RGB LED
        Resolver.Log.Info("Initializing onboard RGB LED");
        onboardLed = new RgbPwmLed(
            redPwmPin: Device.Pins.OnboardLedRed,
            greenPwmPin: Device.Pins.OnboardLedGreen,
            bluePwmPin: Device.Pins.OnboardLedBlue,
            CommonType.CommonAnode);
        Resolver.Log.Info("RGB LED up");

        //==== instantiate the project lab hardware
        projLab = ProjectLab.Create();

        Resolver.Log.Info($"Running on ProjectLab Hardware {projLab.RevisionString}");

        //---- display controller (handles display updates)
        if (projLab.Display is { } display)
        {
            Resolver.Log.Trace("Creating DisplayController");
            displayController = new DisplayController(display);
            Resolver.Log.Trace("DisplayController up");
        }

        //---- BH1750 Light Sensor
        if (projLab.LightSensor is { } bh1750)
        {
            bh1750.Updated += Bh1750Updated;
        }

        //---- BME688 Atmospheric sensor
        if (projLab.EnvironmentalSensor is { } bme688)
        {
            bme688.Updated += Bme688Updated;
        }

        //---- BMI270 Accel/IMU
        if (projLab.MotionSensor is { } bmi270)
        {
            bmi270.Updated += Bmi270Updated;
        }

        //---- buttons
        if (projLab.RightButton is { } rightButton)
        {
            rightButton.PressStarted += (s, e) => displayController.RightButtonState = true;
            rightButton.PressEnded += (s, e) => displayController.RightButtonState = false;
        }

        if (projLab.DownButton is { } downButton)
        {
            downButton.PressStarted += (s, e) => displayController.DownButtonState = true;
            downButton.PressEnded += (s, e) => displayController.DownButtonState = false;
        }
        if (projLab.LeftButton is { } leftButton)
        {
            leftButton.PressStarted += (s, e) => displayController.LeftButtonState = true;
            leftButton.PressEnded += (s, e) => displayController.LeftButtonState = false;
        }
        if (projLab.UpButton is { } upButton)
        {
            upButton.PressStarted += (s, e) => displayController.UpButtonState = true;
            upButton.PressEnded += (s, e) => displayController.UpButtonState = false;
        }

        //---- heartbeat
        onboardLed.StartPulse(WildernessLabsColors.PearGreen);

        Resolver.Log.Info("Initialization complete");

        return base.Initialize();
    }

    public override Task Run()
    {
        Resolver.Log.Info("Run...");

        //---- BH1750 Light Sensor
        if (projLab.LightSensor is { } bh1750)
        {
            bh1750.StartUpdating(TimeSpan.FromSeconds(5));
        }

        //---- BME688 Atmospheric sensor
        if (projLab.EnvironmentalSensor is { } bme688)
        {
            bme688.StartUpdating(TimeSpan.FromSeconds(5));
        }

        //---- BMI270 Accel/IMU
        if (projLab.MotionSensor is { } bmi270)
        {
            bmi270.StartUpdating(TimeSpan.FromSeconds(5));
        }

        if (displayController != null)
        {
            displayController.Update();
        }

        Resolver.Log.Info("starting blink");
        onboardLed.StartBlink(WildernessLabsColors.PearGreen, TimeSpan.FromMilliseconds(500), TimeSpan.FromMilliseconds(2000), 0.5f);

        return base.Run();
    }


    private void Bmi270Updated(object sender, IChangeResult<(Acceleration3D? Acceleration3D, AngularVelocity3D? AngularVelocity3D, Temperature? Temperature)> e)
    {
        Resolver.Log.Info($"BMI270: {e.New.Acceleration3D.Value.X.Gravity:0.0},{e.New.Acceleration3D.Value.Y.Gravity:0.0},{e.New.Acceleration3D.Value.Z.Gravity:0.0}g");
        if (displayController != null)
        {
            displayController.AccelerationConditions = e.New;
        }
    }

    private void Bme688Updated(object sender, IChangeResult<(Temperature? Temperature, RelativeHumidity? Humidity, Pressure? Pressure, Resistance? GasResistance)> e)
    {
        Resolver.Log.Info($"BME688: {(int)e.New.Temperature?.Celsius}C - {(int)e.New.Humidity?.Percent}% - {(int)e.New.Pressure?.Millibar}mbar");
        if (displayController != null)
        {
            displayController.AtmosphericConditions = e.New;
        }
    }

    private void Bh1750Updated(object sender, IChangeResult e)
    {
        Resolver.Log.Info($"BH1750: {e.New.Lux}");
        if (displayController != null)
        {
            displayController.LightConditions = e.New;
        }
    }
}

在我們的主類中，主要需要考慮的是：

• 在Initialize()方法中，我們在做的時候先創(chuàng)建了一個ProjectLab對象（命名為projLab ）ProjectLab.Create()，它方便的封裝了它板載的所有外設(shè)，所以我們只關(guān)注使用它們而不是在每個項目上實例化它上面的每個組件。
• 在訪問外設(shè)之前，我們首先檢查它是否可用，如果可用，我們就可以使用它。比如 ,if (projLab.Display is { } display)表示如果Display的屬性projLab 不為null，則其對象賦值給display，我們可以將其作為參數(shù)傳給我們的DisplayController類。
• 對于環(huán)境、光線和運動傳感器，我們將它們連接到它們各自的事件，這些事件每 5 秒觸發(fā)一次（在此處Updated詳細了解我們?nèi)绾问褂脗鞲衅?/font>）。
• 對于按鈕，我們在每個按鈕上連接PressStarted和PressEnded事件，并將狀態(tài)分配給 上顯示的相應(yīng)屬性DisplayController，因此當您按下任何按鈕時，它們將立即在顯示屏上更新。
• 在最后一個Run()方法中，我們調(diào)用Update()該DisplayController對象以顯示初始 UI 以及所有具有當前值的外圍設(shè)備，并使 Meadow 的板載 LED 閃爍為綠色。

第 5 步 - 運行項目