diff --git a/WaveshareUARTFingerprintSensor.Sample/Program.cs b/WaveshareUARTFingerprintSensor.Sample/Program.cs
index ceb7f0d..1766ee7 100644
--- a/WaveshareUARTFingerprintSensor.Sample/Program.cs
+++ b/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");
 
diff --git a/WaveshareUARTFingerprintSensor/FingerprintSensor.cs b/WaveshareUARTFingerprintSensor/FingerprintSensor.cs
index 76fa339..5a71883 100644
--- a/WaveshareUARTFingerprintSensor/FingerprintSensor.cs
+++ b/WaveshareUARTFingerprintSensor/FingerprintSensor.cs
@@ -18,6 +18,7 @@ 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);
@@ -177,6 +178,36 @@ namespace WaveshareUARTFingerprintSensor
             _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())
diff --git a/WaveshareUARTFingerprintSensor/UserPermission.cs b/WaveshareUARTFingerprintSensor/UserPermission.cs
new file mode 100644
index 0000000..a9f57ff
--- /dev/null
+++ b/WaveshareUARTFingerprintSensor/UserPermission.cs
@@ -0,0 +1,9 @@
+namespace WaveshareUARTFingerprintSensor
+{
+    public enum UserPermission
+    {
+        Level1 = 1,
+        Level2 = 2,
+        Level3 = 3
+    }
+}
\ No newline at end of file
diff --git a/WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.csproj b/WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.csproj
index 93b814a..870a979 100644
--- a/WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.csproj
+++ b/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>