Add doc comments

Should sleep more

WaveshareUARTFingerprintSensor/FingerprintSensor.cs

@@ -79,7 +79,7 @@ namespace WaveshareUARTFingerprintSensor
         {
             byte checksum = 0;
 
-            for (int i = 1; i < length + 1; i++)
+            for (int i = 1; i < length; i++)
             {
                 checksum ^= data[i];
             }
@@ -166,6 +166,9 @@ namespace WaveshareUARTFingerprintSensor
 
         private byte[] ReadData(int length)
         {
+            // Needed to work
+            Thread.Sleep(150);
+
             byte first = (byte)_serialPort.ReadByte();
 
             if (first != PacketSeparator)
@@ -344,7 +347,7 @@ namespace WaveshareUARTFingerprintSensor
         /// <returns></returns>
         public bool TryComparison1N(out (ushort userID, UserPermission permission) userInfo)
         {
-            if (TrySendAndReceive(CommandType.Comparison11, 0, 0, 0, out var response, 1000))
+            if (TrySendAndReceive(CommandType.Comparison1N, 0, 0, 0, out var response, 1000))
             {
                 if (response.responseType != ResponseType.NoUser && response.responseType != ResponseType.Timeout)
                 {
@@ -369,13 +372,13 @@ namespace WaveshareUARTFingerprintSensor
                 {
                     userPermission = (UserPermission)reponse.responseType;
 
-                    return true;
+                    return userPermission != 0;
                 }
             }
 
             userPermission = default;
 
-            return true;
+            return false;
         }
 
         public bool TryGetComparisonLevel(out byte comparisonLevel)
@@ -395,6 +398,11 @@ namespace WaveshareUARTFingerprintSensor
             return false;
         }
 
+        /// <summary>
+        /// Set comparison level used to compare fingerprints
+        /// </summary>
+        /// <param name="comparisonLevel">A value in 0..9 range, 9 is the strictest, default is 5</param>
+        /// <returns></returns>
         public bool TrySetComparisonLevel(byte comparisonLevel)
         {
             if (comparisonLevel < 0 || comparisonLevel > 9)

WaveshareUARTFingerprintSensor/Utils.cs

@@ -13,5 +13,7 @@ namespace WaveshareUARTFingerprintSensor
 
         public static (byte high, byte low) Split(ushort value) => ((byte)(value >> 8), (byte)(value & 0xFF));
         public static (byte first, byte second, byte third) Split(uint value) => ((byte)(value >> 16 & 0xFF), (byte)(value >> 8 & 0xFF), (byte)(value & 0xFF));
+
+        public static string ArrayDisplay<T>(T[] arr) => $"[ {string.Join(", ", arr)} ]";
     }
 }