如果我尝试打开 PWM 引脚，Windows 10 Iot Core 应用程序会崩溃

我想为我的蜂鸣器打开一个 PWM 引脚。但如果我尝试打电话给pwmController.OpenPin(6)方法，应用程序崩溃并显示System.Runtime.InteropServices.SEHException.

我已经仔细检查过示例来源，例如ms-物联网样本 https://github.com/ms-iot/BusProviders/blob/develop/PWM/SamplePwmConsumer/StartupTask.cs。但我看不到我的问题是什么。

一个想法是缺少一些权限，但如果我尝试添加例如<iot:Capability Name="lowLevelDevices" />，我无法再构建该应用程序。

Source

private PwmPin buzzerPin;
private PwmController pwmController;

public RainbowHAT()
{
    // ... do something else
    InitAsync();
}

private async void InitAsync()
{
    Logger.Log(this, "Init");

    // Setup PWM controller.
    if (LightningProvider.IsLightningEnabled)
    {
        LowLevelDevicesController.DefaultProvider = LightningProvider.GetAggregateProvider();
    }

    var pwmControllers = await PwmController.GetControllersAsync(LightningPwmProvider.GetPwmProvider());
    if (pwmControllers == null || pwmControllers.Count < 2)
    {
        throw new OperationCanceledException("Operation canceled due missing GPIO controller");
    }

    pwmController = pwmControllers[1];
    pwmController.SetDesiredFrequency(50);

    // Setup buzzer
    buzzerPin = pwmController.OpenPin(13); <-- CRASH
    buzzerPin.SetActiveDutyCyclePercentage(0.05);
    buzzerPin.Start();
}

我也尝试了以下方法减少所需的最低 Windows 版本的提示 https://stackoverflow.com/questions/49461643/initiate-pwm-on-a-raspberry-pi-runs-in-a-sehexception，但这也没有帮助。

PWM控制器需要Lightning支持。所以你需要将控制器驱动程序设置为直接内存映射驱动程序 https://learn.microsoft.com/en-us/windows/iot-core/develop-your-app/lightningproviders. Here https://github.com/paks/pwm是一个关于 Raspberry Pi 上 PWM 的示例。

您还需要修改代码如下：

    private async void InitAsync()
    {
        Logger.Log(this, "Init");

        // Setup PWM controller.
        if (LightningProvider.IsLightningEnabled)
        {
            var pwmControllers = await PwmController.GetControllersAsync(LightningPwmProvider.GetPwmProvider());
            if (pwmControllers == null || pwmControllers.Count < 2)
            {
                throw new OperationCanceledException("Operation canceled due missing GPIO controller");
            }

            pwmController = pwmControllers[1];
            pwmController.SetDesiredFrequency(50);

            // Setup buzzer
            buzzerPin = pwmController.OpenPin(13);
            buzzerPin.SetActiveDutyCyclePercentage(0.05);
            buzzerPin.Start();
        }
    }