从类之外获取SPI温度数据 [英] Getting SPI temperature data from outside of class

问题描述

我试图写一个类温度的处理与通过SPI我树莓派通信读一些温度数据。我们的目标是能够从我的温度等级之外调用getTemp（）这个方法，这样我可以使用的温度数据，每当我需要在我的程序的其余部分。

I'm trying to write a class "Temperature" that handles communicating with my RaspberryPi through SPI to read some temperature data. The goal is to be able to call a GetTemp() method from outside of my Temperature class so that I can use temperature data whenever I need it in the rest of my program.

我的代码设置是这样的：

My code is set up like this:

public sealed class StartupTask : IBackgroundTask
{
    private BackgroundTaskDeferral deferral;

    public void Run(IBackgroundTaskInstance taskInstance)
    {
        deferral = taskInstance.GetDeferral();

        Temperature t = new Temperature();

        //Want to be able to make a call like this throughout the rest of my program to get the temperature data whenever its needed
        var data = t.GetTemp();
    }
}

温度等级：

Temperature class:

class Temperature
{
    private ThreadPoolTimer timer;
    private SpiDevice thermocouple;
    public byte[] temperatureData = null;

    public Temperature()
    {
        InitSpi();
        timer = ThreadPoolTimer.CreatePeriodicTimer(GetThermocoupleData, TimeSpan.FromMilliseconds(1000));

    }
    //Should return the most recent reading of data to outside of this class
    public byte[] GetTemp()
    {
        return temperatureData;
    }

    private async void InitSpi()
    {
        try
        {
            var settings = new SpiConnectionSettings(0);
            settings.ClockFrequency = 5000000;
            settings.Mode = SpiMode.Mode0;

            string spiAqs = SpiDevice.GetDeviceSelector("SPI0");
            var deviceInfo = await DeviceInformation.FindAllAsync(spiAqs);
            thermocouple = await SpiDevice.FromIdAsync(deviceInfo[0].Id, settings);
        }

        catch (Exception ex)
        {
            throw new Exception("SPI Initialization Failed", ex);
        }
    }

    private void GetThermocoupleData(ThreadPoolTimer timer)
    {
        byte[] readBuffer = new byte[4];
        thermocouple.Read(readBuffer);
        temperatureData = readBuffer;
    }
}

当我在GetThermocoupleData（）添加一个断点，我可以看到，我得到正确的传感器数据值。然而，当我从我的类以外的调用t.GetTemp（），我值为NULL。

When I add a breakpoint in GetThermocoupleData(), I can see that I am getting the correct sensor data values. However when I call t.GetTemp() from outside of my class, my value is always null.

谁能帮我找出我做错了吗？谢谢你。

Can anyone help me figure out what I'm doing wrong? Thank you.

推荐答案

GetThermocouplerData（）必须已经调用ATLEAST一次返回的数据。在您的代码示例它不会一直运行，直到实例化之后1秒。只需在您try块的最后一行添加到GetThermocoupleData（空）的InitSpi通话，以便它开始了已经有至少1个电话。

GetThermocouplerData() must have been called atleast once to return data. In your code sample it will not have been run until 1 second after instantiation. Just add a call to GetThermocoupleData(null) in InitSpi in the last line of your try block so that it starts off already having at least 1 call.

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