Add SensorStateException

Throws an exception if trying to send
a command while the sensor is sleeping

WaveshareUARTFingerprintSensor.Sample/Program.cs

@@ -19,9 +19,9 @@ namespace WaveshareUARTFingerprintSensor.Sample
 
             sensor.Start();
 
-            sensor.Waked += s => sensor.Wake();
+            Console.WriteLine("Adding fingerprint");
 
-            sensor.Sleep();
+            var response = sensor.AddFingerprint(40, UserPermission.Level3);
 
             Console.WriteLine("End");
 

WaveshareUARTFingerprintSensor/Exceptions/SensorStateException.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace WaveshareUARTFingerprintSensor.Exceptions
+{
+    [Serializable]
+    public class SensorStateException : Exception
+    {
+        public const string SensorSleepingMessage = "Sensor is sleeping, can't send commands";
+
+        public SensorStateException() { }
+        public SensorStateException(string message) : base(message) { }
+        public SensorStateException(string message, Exception inner) : base(message, inner) { }
+        protected SensorStateException(
+          System.Runtime.Serialization.SerializationInfo info,
+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }
+    }
+}

WaveshareUARTFingerprintSensor/FingerprintSensor.cs

@@ -10,6 +10,7 @@ using System.Threading.Tasks;
 using Unosquare.RaspberryIO;
 using Unosquare.RaspberryIO.Abstractions;
 using Unosquare.WiringPi;
+using WaveshareUARTFingerprintSensor.Exceptions;
 
 namespace WaveshareUARTFingerprintSensor
 {
@@ -18,6 +19,7 @@ namespace WaveshareUARTFingerprintSensor
         public const string PrimarySerialPort = "/dev/ttyAMA0";
         public const string SecondarySerialPort = "/dev/ttyS0";
         public const int DefaultTimeout = 10_000;
+        public const int MaxUserID = 0xFFF;
 
         public event WakedEventHandler Waked;
         public delegate void WakedEventHandler(FingerprintSensor sender);
@@ -27,11 +29,12 @@ namespace WaveshareUARTFingerprintSensor
         private const byte PacketSeparator = 0xF5;
 
         private SerialPort _serialPort;
-        private int _wakePinNumber;
-        private int _rstPinNumber;
+        private readonly int _wakePinNumber;
+        private readonly int _rstPinNumber;
         private IGpioPin _wakePin;
         private IGpioPin _rstPin;
-        private object _lock = new object();
+        private bool _sleeping = false;
+        private readonly object _lock = new object();
 
         public FingerprintSensor(string portName, int wakePin = 23, int rstPin = 24)
         {
@@ -74,6 +77,11 @@ namespace WaveshareUARTFingerprintSensor
 
         private (byte first, byte second, ResponseType responseType) SendAndReceive(CommandType commandType, byte first, byte second, byte third, int timeout = DefaultTimeout)
         {
+            if (_sleeping)
+            {
+                throw new SensorStateException(SensorStateException.SensorSleepingMessage);
+            }
+
             // Command packet
             byte[] buffer = { PacketSeparator, (byte)commandType, first, second, third, 0, 0, PacketSeparator };
 
@@ -169,14 +177,46 @@ namespace WaveshareUARTFingerprintSensor
 
         public void Sleep()
         {
+            _sleeping = true;
             _rstPin.Write(GpioPinValue.Low);
         }
 
         public void Wake()
         {
+            _sleeping = false;
             _rstPin.Write(GpioPinValue.High);
         }
 
+        public ResponseType AddFingerprint(ushort userID, UserPermission userPermission)
+        {
+            if (userID > MaxUserID)
+            {
+                return ResponseType.Full;
+            }
+
+            CommandType[] commands = { CommandType.AddFingerprint1, CommandType.AddFingerprint2, CommandType.AddFingerprint3 };
+            (byte idHigh, byte idLow) = Utils.Split(userID);
+
+            foreach (var command in commands)
+            {
+                if (TrySendAndReceive(command, idHigh, idLow, (byte)userPermission, out var response))
+                {
+                    if (response.responseType != ResponseType.Success)
+                    {
+                        return response.responseType;
+                    }
+                }
+                else
+                {
+                    return ResponseType.Timeout;
+                }
+
+                Thread.Sleep(50);
+            }
+
+            return ResponseType.Success;
+        }
+
         private void OnWake()
         {
             if (_wakePin.Read())

WaveshareUARTFingerprintSensor/UserPermission.cs

@@ -0,0 +1,9 @@
+namespace WaveshareUARTFingerprintSensor
+{
+    public enum UserPermission
+    {
+        Level1 = 1,
+        Level2 = 2,
+        Level3 = 3
+    }
+}

WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.csproj

@@ -65,6 +65,7 @@
     <Compile Include="FingerprintSensor.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ResponseType.cs" />
+    <Compile Include="UserPermission.cs" />
     <Compile Include="Utils.cs" />
   </ItemGroup>
   <ItemGroup>