first commit

Software/CSharp/GrovePi/Sensors/RealTimeClock.cs

@@ -0,0 +1,31 @@
+using System;
+
+namespace GrovePi.Sensors
+{
+    public interface IRealTimeClock
+    {
+        byte[] Read();
+    }
+
+    internal class RealTimeClock : IRealTimeClock
+    {
+        private const byte CommandAddress = 30;
+        private readonly GrovePi _device;
+        private readonly Pin _pin;
+
+        internal RealTimeClock(GrovePi device, Pin pin)
+        {
+            if (device == null) throw new ArgumentNullException(nameof(device));
+            _device = device;
+            _pin = pin;
+        }
+
+        public byte[] Read()
+        {
+            var buffer = new[] {CommandAddress, (byte) _pin, Constants.Unused, Constants.Unused};
+            _device.DirectAccess.Write(buffer);
+            _device.DirectAccess.Read(buffer);
+            return buffer;
+        }
+    }
+}