Windows 10 IoT Core Max31855

RPi GPIO

Name	Board Pin
VCC	1/17
GND	6/9/14/20/25/30/34/39
3Vo	N/A
CS	24
SCK	23
D0	21

using System;
using Windows.Devices.Enumeration;
using Windows.Devices.Spi;

namespace CYFang
{
    /// <summary>
    /// Max31855
    /// </summary>
    public sealed class Max31855 : IDisposable
    {
        /// <summary>
        /// SPI
        /// </summary>
        private SpiDevice sensor;

        /// <summary>
        /// read buff
        /// </summary>
        private byte[] readBuff = new byte[4];

        /// <summary>
        ///
        /// </summary>
        public Max31855() { this.InitSPI(); }

        /// <summary>
        /// Dispose
        /// </summary>
        public void Dispose()
        {
            if (sensor != null)
            {
                sensor.Dispose();
                sensor = null;
            }
        }

        /// <summary>
        /// 取得IC溫度
        /// </summary>
        /// <returns></returns>
        public double GetInternalTemperatureDataCelcius()
        {
            GetThermocoupleData();
            uint data = BitConverter.ToUInt32(readBuff, 0);
            data >>= 4;

            double celsius = data & 0x7FF;
            if ((data & 0x800) == 1)
            {
                celsius = 0xF800 | (data & 0x7FF);
            }

            //15 to 4 /= 16.0
            celsius /= 16.0;
            return celsius;
        }

        /// <summary>
        /// 取得IC華氏溫度
        /// </summary>
        /// <returns></returns>
        public double GetInternalTemperatureDataFahrenheit() { return ConvertCelsiusToFahrenheit(GetInternalTemperatureDataCelcius()); }

        /// <summary>
        /// 取得K型接頭溫度
        /// </summary>
        /// <returns></returns>
        public double GetProbeTemperatureDataCelsius()
        {
            GetThermocoupleData();
            uint data = BitConverter.ToUInt32(readBuff, 0);

            data = ((data & 0x80000000) != 0) ?
            data = ((data >> 18) & 0x00003FFFF) | 0xFFFFC000 :
            data >>= 18;

            double celsius = data;
            // 31 to 18 = /=4.0
            celsius /= 4.0f;
            return celsius;
        }

        /// <summary>
        /// 取得K型接頭華氏溫度
        /// </summary>
        /// <returns></returns>
        public double GetProbeTemperatureDataFahrenheit() { return ConvertCelsiusToFahrenheit(GetProbeTemperatureDataCelsius()); }

        /// <summary>
        /// Init SPI
        /// </summary>
        private async void InitSPI()
        {
            var settings = new SpiConnectionSettings(0)
            {
                ClockFrequency = 5000000,
                Mode = SpiMode.Mode0
            };
            string spiAqs = SpiDevice.GetDeviceSelector("SPI0");
            var deviceInfo = await DeviceInformation.FindAllAsync(spiAqs);
            this.sensor = await SpiDevice.FromIdAsync(deviceInfo[0].Id, settings);
        }

        /// <summary>
        /// 取得數值
        /// </summary>
        private void GetThermocoupleData()
        {
            byte[] readBuff = new byte[4];
            sensor.Read(readBuff);
            Array.Reverse(readBuff);
            this.readBuff = readBuff;
        }

        /// <summary>
        /// 攝氏轉華氏
        /// </summary>
        /// <param name="c">攝氏</param>
        /// <returns></returns>
        private double ConvertCelsiusToFahrenheit(double c)
        {
            c *= 9.0;
            c /= 5.0;
            c += 32;
            return c;
        }

    }
}