first commit

Software/CSharp/GrovePi/I2CDevices/SHTTemperatureAndHumiditySensor.cs

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+using Windows.Devices.I2c;
+
+namespace GrovePi.I2CDevices
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public interface ISHTTemperatureAndHumiditySensor
+    {
+        double TemperatureInCelsius { get; }
+        double TemperatureInFahrenheit { get; }
+        double RelativeHumidity { get; }
+        void Measure();
+    }
+
+    /// <summary>
+    /// Specifies the model of sensor.
+    /// </summary>
+    public enum SHTModel
+    {
+        Sht31 = 0
+    }
+
+    /// <summary>
+    /// The repeatability setting influences the measurement duration and the current
+    /// consumption of the sensor.
+    /// </summary>
+    public enum MeasurementMode
+    {
+        HighRepeatClockStretch = 0,
+        MediumRepeatClockStretch,
+        LowRepeatClockStretch,
+        HighRepeat,
+        MediumRepeat,
+        LowRepeat
+    }
+
+    internal class SHTTemperatureAndHumiditySensor : ISHTTemperatureAndHumiditySensor
+    {
+        private readonly SHTModel _model;
+        internal I2cDevice _device;
+
+        private byte[] MeasureHighClockStretch = new byte[2] { 0x2C, 0x06 };
+        private byte[] MeasureMediumClockStretch = new byte[2] { 0x2C, 0x0D };
+        private byte[] MeasureLowClockStretch = new byte[2] { 0x2C, 0x10 };
+        private byte[] MeasureHigh = new byte[2] { 0x24, 0x00 };
+        private byte[] MeasureMedium = new byte[2] { 0x24, 0x0B };
+        private byte[] MeasureLow = new byte[2] { 0x24, 0x16 };
+
+        private byte[] ReadStatusRegisterCommandAddress = new byte[2] { 0xF3, 0x2D };
+        private byte[] ClearStatusRegisterCommandAddress = new byte[2] { 0x30, 0x41 };
+        private byte[] SoftResetCommandAddress = new byte[2] { 0x30, 0xA2 };
+        private byte[] EnableHeaterCommandAddress = new byte[2] { 0x30, 0x6D };
+        private byte[] DisableHeaderCommandAddress = new byte[2] { 0x30, 0x66 };
+        private byte[] BreakCommandAddress = new byte[2] { 0x30, 0x93 };
+
+        private byte[] _sensorData = new byte[6];
+        private byte[] _sensorCommand = new byte[4];
+
+        public double TemperatureInCelsius { get; set; }
+        public double TemperatureInFahrenheit { get; set; }
+        public double RelativeHumidity { get; set; }
+
+        internal SHTTemperatureAndHumiditySensor(I2cDevice sensorDevice, SHTModel model, MeasurementMode measureMode)
+        {
+            _device = sensorDevice;
+            _model = model;
+
+            switch (measureMode)
+            {
+                case MeasurementMode.HighRepeatClockStretch:
+                    _sensorCommand = MeasureHighClockStretch;
+                    break;
+                case MeasurementMode.MediumRepeatClockStretch:
+                    _sensorCommand = MeasureMediumClockStretch;
+                    break;
+                case MeasurementMode.LowRepeatClockStretch:
+                    _sensorCommand = MeasureLowClockStretch;
+                    break;
+                case MeasurementMode.HighRepeat:
+                    _sensorCommand = MeasureHigh;
+                    break;
+                case MeasurementMode.MediumRepeat:
+                    _sensorCommand = MeasureMedium;
+                    break;
+                case MeasurementMode.LowRepeat:
+                    _sensorCommand = MeasureLow;
+                    break;
+                default:
+                    _sensorCommand = MeasureHigh;
+                    break;
+            }
+        }
+
+        public void Measure()
+        {
+            _device.WriteRead(_sensorCommand, _sensorData);
+
+            TemperatureInCelsius = (((_sensorData[0] * 256) + _sensorData[1]) * 175.0) / 65535.0 - 45.0;
+            TemperatureInFahrenheit = (((_sensorData[0] * 256) + _sensorData[1]) * 315.0) / 65535.0 - 49.0;
+            RelativeHumidity = (((_sensorData[3] * 256) + _sensorData[4])) * 100.0 / 65535.0 - 6.0;
+        }
+
+        /// <summary>
+        /// This triggers the sensor to reset its system controller and reloads calibration data from the memory.
+        /// </summary>
+        public void Reset()
+        {
+            _device.Write(SoftResetCommandAddress);
+        }
+
+        /// <summary>
+        /// All flags (Bit 15, 11, 10, 4) in the status register can be cleared (set to zero)
+        /// </summary>
+        public void ClearStatusRegister()
+        {
+            _device.Write(ClearStatusRegisterCommandAddress);
+        }
+
+        /// <summary>
+        /// The status register contains information on the operational status of the heater, the alert mode and on
+        /// the execution status of the last command and the last write sequence.
+        /// </summary>
+        /// <returns>16bit status register response</returns>
+        public byte[] ReadStatusRegister()
+        {
+            var statusResponse = new byte[2];
+            _device.WriteReadPartial(ReadStatusRegisterCommandAddress, statusResponse);
+            return statusResponse;
+        }
+
+        /// <summary>
+        /// The heater can be switched on and off by command
+        /// </summary>
+        public void EnableHeater()
+        {
+            _device.Write(EnableHeaterCommandAddress);
+        }
+
+        public void DisableHeater()
+        {
+            _device.Write(DisableHeaderCommandAddress);
+        }
+
+        /// <summary>
+        /// It is rrecommended to stop the periodic data acquisition prior to sending another command using the break command.
+        /// Upon reception of the break command the sensor enters the single shot mode.
+        /// </summary>
+        internal void Break()
+        {
+            _device.Write(BreakCommandAddress);
+        }
+
+    }
+}