Update README.md

Fix typo

README.md

@@ -0,0 +1,69 @@
+# Waveshare UART fingerprint sensor (C)
+
+A C# library for the [**Waveshare UART fingerprint sensor (C)**][Sensor], running on
+.Net Framework 4.7 (**Mono**) on a **Raspberry Pi**
+
+This library is tested using a Raspberry Pi Zero (hence the use of Mono)
+but should work on any Raspberry.  
+It should also be easily portable to any device that supports Mono
+or an equivalent (*.Net Core*).
+
+## Usage
+
+- First install it from [**nuget**](https://www.nuget.org/packages/WaveshareUARTFingerprintSensor/)
+
+Then you only need to start the sensor
+
+```csharp
+// PrimarySerialPort refers to /dev/ttyAMA0
+// SecondarySerialPort refers to /dev/ttyS0
+// You need to choose it according to your Raspberry
+// Check the table below
+var sensor = new FingerprintSensor(FingerprintSensor.PrimarySerialPort);
+
+sensor.Start();
+
+// Do any command
+
+// Example: get the user count
+if (sensor.TryGetUserCount(out ushort count))
+{
+    Console.WriteLine($"User count: {count}");
+}
+```
+
+Here is a table of which serial port to use on which Raspberry Pi,
+it may be different for you
+
+| Model     | Port                   |
+| --------- | ---------------------- |
+| Pi Zero   | Primary (/dev/ttyAMA0) |
+| Pi Zero W | Secondary (/dev/ttyS0) |
+| Pi 1      | Primary (/dev/ttyAMA0) |
+| Pi 2      | Primary (/dev/ttyAMA0) |
+| Pi 3      | Secondary (/dev/ttyS0) |
+| Pi 4      | Secondary (/dev/ttyS0) |
+
+> The Secondary UART is **disabled by default**, you an activate it in `raspi-config`  
+> [**Source**](https://www.raspberrypi.org/documentation/configuration/uart.md)
+
+## Sample App
+
+You can find a [**sample app**](WaveshareUARTFingerprintSensor.Sample) which shows basic usages of
+this library and may help you to understand how to use it
+
+## Contributing
+
+If you have a feature idea or want to report a bug, don't hesitate to create a new
+[**Issue**](https://github.com/Eveldee/WaveshareUARTFingerprintSensor/issues) or do a
+[**Pull Request**](https://github.com/Eveldee/WaveshareUARTFingerprintSensor/pulls)
+
+## Copyright and license
+
+*[**WaveshareUARTFingerprintSensor**](README.md)* library is licensed under the [MIT License](LICENSE).
+
+*[**Unosquare.Raspberry.IO**](https://github.com/migueldeicaza/gui.cs/)* library is under the [MIT License](https://github.com/unosquare/raspberryio/blob/master/LICENSE).
+
+
+<!-- Links -->
+[Sensor]: https://www.waveshare.com/wiki/UART_Fingerprint_Sensor_(C)

WaveshareUARTFingerprintSensor.Sample/Program.cs

@@ -5,27 +5,19 @@ using System.Linq;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
+using Terminal.Gui;
 using Unosquare.RaspberryIO;
 using Unosquare.RaspberryIO.Abstractions;
 using Unosquare.WiringPi;
-
+using WaveshareUARTFingerprintSensor.Sample.Views;
+
 namespace WaveshareUARTFingerprintSensor.Sample
 {
     class Program
     {
         static void Main(string[] args)
         {
-            var sensor = new FingerprintSensor(FingerprintSensor.PrimarySerialPort);
-
-            sensor.Start();
-
-            sensor.Waked += s => sensor.Wake();
-
-            sensor.Sleep();
-
-            Console.WriteLine("End");
-
-            Thread.Sleep(-1);
+            Application.Run<TUIManager>();
         }
     }
 }

WaveshareUARTFingerprintSensor.Sample/README.md

@@ -0,0 +1,24 @@
+# Sample App
+
+A sample app for the [Waveshare UART fingerprint sensor (C) library](../README.md)
+
+![Sample](../Sample.png)
+
+[![asciicast](https://asciinema.org/a/U1cBQzJ3ueFyN0urkh2NRcjB9.svg)](https://asciinema.org/a/U1cBQzJ3ueFyN0urkh2NRcjB9)
+
+## Build
+
+You can compile it using any **C# IDE** that supports **.Net Framework** or by running
+`dotnet build` in a **terminal** using [**.Net CLI**](https://docs.microsoft.com/en-us/dotnet/core/tools/)
+
+## Usage
+
+- Install [**Mono**](https://www.mono-project.com/) on your Raspberry Pi
+- [**Download**](https://github.com/Eveldee/WaveshareUARTFingerprintSensor/releases) or [**Build**](#build) the application
+- Run it with `mono WaveshareUARTFingerprintSensor.Sample.exe`
+
+## Copyright and license
+
+[**WaveshareUARTFingerprintSensor**](../README.md) library is licensed under the [MIT License](../LICENSE).
+
+[**gui.cs**](https://github.com/migueldeicaza/gui.cs/) library is under the [MIT License](https://github.com/migueldeicaza/gui.cs/blob/master/LICENSE).

WaveshareUARTFingerprintSensor.Sample/Views/DataDisplay.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Terminal.Gui;
+
+namespace WaveshareUARTFingerprintSensor.Sample.Views
+{
+    public class DataDisplay : Toplevel
+    {
+        private string _title;
+        private byte[] _data;
+
+        public DataDisplay(string title, byte[] data)
+        {
+            _title = title;
+            _data = data;
+
+            Init();
+        }
+
+        private void Init()
+        {
+            Modal = true;
+
+            ColorScheme = Colors.TopLevel;
+
+            // Creates the top-level window to show
+            var win = new Window(_title)
+            {
+                X = 0,
+                Y = 0,
+
+                // By using Dim.Fill(), it will automatically resize without manual intervention
+                Width = Dim.Fill(),
+                Height = Dim.Fill()
+            };
+
+            win.ColorScheme = Colors.ColorSchemes["Dialog"];
+
+            Add(win);
+
+            var quitButton = new Button("_Ok")
+            {
+                X = Pos.Right(this) - 9,
+                Y = Pos.Bottom(this) - 2
+            };
+            quitButton.Clicked += () => Application.RequestStop();
+
+            var stream = new MemoryStream(_data);
+            var text = new HexView(stream)
+            {
+                X = Pos.Center(),
+                Y = Pos.Center(),
+                Height = Dim.Fill() - 5,
+                Width = Dim.Fill() - 2,
+                AllowEdits = false
+            };
+
+            Add(text, quitButton);
+        }
+    }
+}

WaveshareUARTFingerprintSensor.Sample/Views/EntryDialog.cs

@@ -0,0 +1,87 @@
+using NStack;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Terminal.Gui;
+
+namespace WaveshareUARTFingerprintSensor.Sample.Views
+{
+    public class EntryDialog : Dialog
+    {
+        private Func<ustring, bool> _validator;
+        private bool _success;
+        private string _title;
+        private string _errorMessage;
+
+        public EntryDialog(string title, Func<ustring, bool> validator = null, string errorMessage = "") : base(title, 60, 7)
+        {
+            _title = title;
+            _errorMessage = errorMessage;
+
+            _validator = validator;
+
+            ColorScheme = Colors.ColorSchemes["Menu"];
+        }
+
+        public bool TryShow(out ustring input)
+        {
+            _success = false;
+
+            var levelEntry = new TextField("")
+            {
+                X = 1,
+                Y = 2,
+                Width = Dim.Fill(),
+                Height = 1
+            };
+
+            var cancelButton = new Button("_Cancel")
+            {
+                X = Pos.Percent(82),
+                Y = Pos.Percent(95)
+            };
+            cancelButton.Clicked += () => Application.RequestStop();
+
+
+            var okButton = new Button("_Ok")
+            {
+                X = Pos.Percent(70),
+                Y = Pos.Percent(95)
+            };
+            okButton.Clicked += () => CheckInput(levelEntry.Text);
+
+            Add(levelEntry, okButton, cancelButton);
+
+            levelEntry.SetFocus();
+
+            Application.Run(this);
+
+            if (_success)
+            {
+                input = levelEntry.Text;
+
+                return true;
+            }
+
+            input = default;
+
+            return false;
+        }
+
+        private void CheckInput(ustring input)
+        {
+            if (_validator?.Invoke(input) ?? true)
+            {
+                _success = true;
+
+                Application.RequestStop();
+            }
+            else
+            {
+                MessageBox.ErrorQuery(_title, _errorMessage, "Ok");
+            }
+        }
+    }
+}

WaveshareUARTFingerprintSensor.Sample/Views/FingerprintDialog.cs

@@ -0,0 +1,53 @@
+using NStack;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Terminal.Gui;
+
+namespace WaveshareUARTFingerprintSensor.Sample.Views
+{
+    public class FingerprintDialog : Dialog
+    {
+        public string ErrorTitle { get; set; }
+        public string ErrorMessage { get; set; }
+
+        public FingerprintDialog(string errorTitle, string errorMessage) : base(errorTitle, 60, 7)
+        {
+            ErrorTitle = errorTitle;
+            ErrorMessage = errorMessage;
+
+            ColorScheme = Colors.ColorSchemes["Menu"];
+        }
+
+        public void Show()
+        {
+            var label = new Label("Please place your finger flat on the sensor")
+            {
+                X = Pos.Center(),
+                Y = Pos.Center(),
+                Height = 1
+            };
+
+            Add(label);
+
+            Application.Run(this);
+        }
+
+        public void Cancel()
+        {
+            Application.MainLoop.Invoke(() => Application.RequestStop());
+        }
+
+        public void CancelAndShowError()
+        {
+            Application.MainLoop.Invoke(() =>
+            {
+                MessageBox.ErrorQuery(ErrorTitle, ErrorMessage, "Ok");
+
+                Application.RequestStop();
+            });
+        }
+    }
+}

WaveshareUARTFingerprintSensor.Sample/Views/SettingsDisplay.cs

@@ -0,0 +1,73 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Terminal.Gui;
+
+namespace WaveshareUARTFingerprintSensor.Sample.Views
+{
+    public class SettingsDisplay : Toplevel
+    {
+        private string _port;
+        private RadioGroup _radioPort;
+
+        public SettingsDisplay()
+        {
+            Init();
+        }
+
+        private void Init()
+        {
+            Modal = true;
+
+            ColorScheme = Colors.Error;
+
+            // Creates the top-level window to show
+            var win = new Window("Settings")
+            {
+                X = 0,
+                Y = 0,
+
+                // By using Dim.Fill(), it will automatically resize without manual intervention
+                Width = Dim.Fill(),
+                Height = Dim.Fill()
+            };
+
+            win.ColorScheme = Colors.ColorSchemes["Dialog"];
+
+            Add(win);
+
+            // Window Content
+            var portLabel = new Label("Serial Port:")
+            {
+                X = 4,
+                Y = 3
+            };
+            _radioPort = new RadioGroup(new NStack.ustring[] { FingerprintSensor.PrimarySerialPort, FingerprintSensor.SecondarySerialPort })
+            {
+                X = Pos.Right(portLabel) + 2,
+                Y = Pos.Top(portLabel),
+                Width = Dim.Fill()
+            };
+
+            var saveButton = new Button("_Save")
+            {
+                X = Pos.Right(this) - 14,
+                Y = Pos.Bottom(this) - 4
+            };
+            saveButton.Clicked += () => { Save();  Application.RequestStop(); };
+
+            win.Add(portLabel, _radioPort, saveButton);
+        }
+
+        private void Save()
+        {
+            _port = _radioPort.RadioLabels[_radioPort.SelectedItem].ToString();
+
+            File.WriteAllText(TUIManager.SettingsFilePath, _port);
+        }
+    }
+}

WaveshareUARTFingerprintSensor.Sample/Views/SleepDisplay.cs

@@ -0,0 +1,108 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Terminal.Gui;
+
+namespace WaveshareUARTFingerprintSensor.Sample.Views
+{
+    public class SleepDisplay : Toplevel
+    {
+        private FingerprintSensor _fingerprintSensor;
+        private int _count;
+        private int _lastID;
+        private Label _sleepModeLabel;
+        private Label _readCountLabel;
+        private Label _lastReadLabel;
+
+        public SleepDisplay(FingerprintSensor fingerprintSensor)
+        {
+            _fingerprintSensor = fingerprintSensor;
+            _count = 0;
+            _lastID = -1;
+
+            Init();
+        }
+
+        private void Init()
+        {
+            Modal = true;
+
+            ColorScheme = Colors.Error;
+
+            // Creates the top-level window to show
+            var win = new Window("Sleep")
+            {
+                X = 0,
+                Y = 0,
+
+                // By using Dim.Fill(), it will automatically resize without manual intervention
+                Width = Dim.Fill(),
+                Height = Dim.Fill()
+            };
+
+            win.ColorScheme = Colors.ColorSchemes["Dialog"];
+
+            Add(win);
+
+            // Window Content
+            _sleepModeLabel = new Label("Sleep mode is on, waiting for fingerprints...")
+            {
+                X = 2,
+                Y = 1,
+                Width = Dim.Fill()
+            };
+            _readCountLabel = new Label("Read: 0")
+            {
+                X = Pos.Left(_sleepModeLabel),
+                Y = Pos.Bottom(_sleepModeLabel) + 1,
+                Width = Dim.Fill()
+            };
+            _lastReadLabel = new Label("Last User: - 1")
+            {
+                X = Pos.Left(_readCountLabel),
+                Y = Pos.Bottom(_readCountLabel),
+                Width = Dim.Fill()
+            };
+
+            var stopButton = new Button("_Stop")
+            {
+                X = Pos.Right(this) - 11,
+                Y = Pos.Bottom(this) - 2
+            };
+            stopButton.Clicked += () => { _fingerprintSensor.Waked -= FingerprintSensor_Waked; Application.RequestStop(); };
+
+            win.Add(_sleepModeLabel, _readCountLabel, _lastReadLabel);
+
+            Add(stopButton);
+
+            _fingerprintSensor.Waked += FingerprintSensor_Waked;
+
+            _fingerprintSensor.Sleep();
+        }
+
+        private void UpdateInfo()
+        {
+            _readCountLabel.Text = $"Read: {_count}";
+            _lastReadLabel.Text = $"Last User: {_lastID}";
+        }
+
+        private void FingerprintSensor_Waked(FingerprintSensor sender)
+        {
+            _fingerprintSensor.Wake();
+
+            if (_fingerprintSensor.TryComparison1N(out var userInfo))
+            {
+                _count += 1;
+                _lastID = userInfo.userID;
+
+                Application.MainLoop.Invoke(UpdateInfo);
+            }
+
+            _fingerprintSensor.Sleep();
+        }
+    }
+}

WaveshareUARTFingerprintSensor.Sample/Views/TUIManager.cs

@@ -0,0 +1,416 @@
+using NStack;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Terminal.Gui;
+
+namespace WaveshareUARTFingerprintSensor.Sample.Views
+{
+    public class TUIManager : Toplevel
+    {
+        public const string OutputFilePath = "out.txt";
+        public const string SettingsFilePath = "settings.txt";
+
+        private FingerprintSensor _fingerprintSensor;
+        private Label _serialPortLabel;
+        private Label _comparisonLevelLabel;
+        private Label _userCountLabel;
+
+        private object _outputFileLock = new object();
+
+        public TUIManager()
+        {
+            Init();
+        }
+
+        private void Init()
+        {
+            ColorScheme = Colors.Error;
+
+            // Creates the top-level window to show
+            var win = new Window("TUIManager")
+            {
+                X = 0,
+                Y = 1, // Leave one row for the toplevel menu
+
+                // By using Dim.Fill(), it will automatically resize without manual intervention
+                Width = Dim.Fill(),
+                Height = Dim.Fill()
+            };
+
+            win.ColorScheme = Colors.ColorSchemes["Dialog"];
+
+            Add(win);
+
+            // Creates a menubar, the item "New" has a help menu.
+            var menu = new MenuBar(new MenuBarItem[] {
+                new MenuBarItem ("_Options", new MenuItem [] {
+                    new MenuItem ("_Change Config", "", () => { ChangeConfig(); }),
+                    new MenuItem ("_Quit", "", () => { Application.RequestStop(); })
+                })
+            });
+
+            Add(menu);
+
+            // Window Content
+            _serialPortLabel = new Label("Serial Port:")
+            {
+                X = 2,
+                Y = 1,
+                Width = Dim.Fill()
+            };
+            _comparisonLevelLabel = new Label("Comparison Level: 0")
+            {
+                X = Pos.Left(_serialPortLabel),
+                Y = Pos.Bottom(_serialPortLabel),
+                Width = Dim.Fill()
+            };
+            _userCountLabel = new Label("Users: 0")
+            {
+                X = Pos.Left(_comparisonLevelLabel),
+                Y = Pos.Bottom(_comparisonLevelLabel),
+                Width = Dim.Fill()
+            };
+
+            var userCountButton = new Button("Query _User Count")
+            {
+                X = Pos.Center(),
+                Y = 7
+            };
+            userCountButton.Clicked += UserCountButton_Clicked;
+
+            var readFingerprintButton = new Button("_Read Fingerprint")
+            {
+                X = Pos.Center(),
+                Y = Pos.Bottom(userCountButton) + 1
+            };
+            readFingerprintButton.Clicked += ReadFingerprintButton_Clicked;
+
+            var readEigenvaluesButton = new Button("Read _Eigenvalues")
+            {
+                X = Pos.Center(),
+                Y = Pos.Bottom(readFingerprintButton)
+            };
+            readEigenvaluesButton.Clicked += ReadEigenvaluesButton_Clicked;
+
+            var readImageButton = new Button("Read _Image")
+            {
+                X = Pos.Center(),
+                Y = Pos.Bottom(readEigenvaluesButton)
+            };
+            readImageButton.Clicked += ReadImageButton_Clicked;
+
+            var addFingerprintButton = new Button("_Add Fingerprint")
+            {
+                X = Pos.Center(),
+                Y = Pos.Bottom(readImageButton) + 1
+            };
+            addFingerprintButton.Clicked += AddFingerprintButton_Clicked;
+
+            var deleteAFingerprint = new Button("_Delete a Fingerprint")
+            {
+                X = Pos.Center(),
+                Y = Pos.Bottom(addFingerprintButton)
+            };
+            deleteAFingerprint.Clicked += DeleteAFingerprint_Clicked;
+
+            var clearFingerprintsButton = new Button("_Clear Fingerprints")
+            {
+                X = Pos.Center(),
+                Y = Pos.Bottom(deleteAFingerprint)
+            };
+            clearFingerprintsButton.Clicked += ClearFingerprintsButton_Clicked;
+
+            var setComparisonLevelButton = new Button("Set Comparison _Level")
+            {
+                X = Pos.Center(),
+                Y = Pos.Bottom(clearFingerprintsButton) + 1
+            };
+            setComparisonLevelButton.Clicked += SetComparisonLevelButton_Clicked;
+
+            var sleepButton = new Button("_Sleep Mode")
+            {
+                X = Pos.Center(),
+                Y = Pos.Bottom(setComparisonLevelButton) + 1
+            };
+            sleepButton.Clicked += SleepButton_Clicked;
+
+            var quitButton = new Button("_Quit")
+            {
+                X = Pos.Center(),
+                Y = Pos.Percent(95)
+            };
+            quitButton.Clicked += Quit_Clicked;
+
+            win.Add(
+                _serialPortLabel,
+                _comparisonLevelLabel,
+                _userCountLabel,
+                userCountButton,
+                readFingerprintButton,
+                readEigenvaluesButton,
+                readImageButton,
+                addFingerprintButton,
+                deleteAFingerprint,
+                clearFingerprintsButton,
+                setComparisonLevelButton,
+                sleepButton,
+                quitButton
+            );
+
+            // Init Sensor
+            if (!File.Exists(SettingsFilePath))
+            {
+                Application.Run(new SettingsDisplay());
+            }
+
+            InitSensor();
+
+            // Update gui
+            UpdateSerialPort();
+            UpdateUserCount();
+            UpdateComparisonLevel();
+        }
+
+        private void UpdateSerialPort()
+        {
+            _serialPortLabel.Text = $"Serial Port: {_fingerprintSensor.PortName}";
+        }
+
+        private void InitSensor()
+        {
+            _fingerprintSensor = new FingerprintSensor(File.ReadAllText(SettingsFilePath));
+
+            _fingerprintSensor.Start();
+        }
+
+        private void UpdateUserCount()
+        {
+            if (_fingerprintSensor.TryGetUserCount(out ushort count))
+            {
+                _userCountLabel.Text = $"Users: {count}";
+            }
+        }
+
+        private void UpdateComparisonLevel()
+        {
+            if (_fingerprintSensor.TryGetComparisonLevel(out byte comparisonLevel))
+            {
+                _comparisonLevelLabel.Text = $"Comparison Level: {comparisonLevel}";
+            }
+        }
+
+        private void ReadImageButton_Clicked()
+        {
+            var dialog = new FingerprintDialog("Acquire Image", "Can't acquire image, try to place your finger flat on the sensor");
+            byte[] image = null;
+
+            Task.Run(() =>
+            {
+                if (_fingerprintSensor.TryAcquireImage(out image))
+                {
+                    dialog.Cancel();
+                }
+                else
+                {
+                    dialog.CancelAndShowError();
+                }
+            });
+
+            dialog.Show();
+
+            if (image != null)
+            {
+                WriteOut($"Image:\n{Utils.ArrayDisplay(image)}\n\n\n");
+
+                var window = new DataDisplay("Image", image.ToArray());
+
+                Application.Run(window);
+            }
+        }
+
+        private void ReadEigenvaluesButton_Clicked()
+        {
+            var dialog = new FingerprintDialog("Acquire Eigenvalues", "Can't acquire eigenvalues, try to place your finger flat on the sensor");
+            byte[] eigenvalues = null;
+
+            Task.Run(() =>
+            {
+                if (_fingerprintSensor.TryAcquireEigenvalues(out var values))
+                {
+                    eigenvalues = values.ToArray();
+
+                    dialog.Cancel();
+                }
+                else
+                {
+                    dialog.CancelAndShowError();
+                }
+            });
+
+            dialog.Show();
+
+            if (eigenvalues != null)
+            {
+                var window = new DataDisplay("Eigenvalues", eigenvalues);
+
+                 WriteOut($"Eigenvalues:\n{Utils.ArrayDisplay(eigenvalues)}\n\n\n");
+
+                Application.Run(window);
+            }
+        }
+
+        private void SetComparisonLevelButton_Clicked()
+        {
+            if (new EntryDialog("Comparison Level", i => int.TryParse(i.ToString(), out var n) && n > 0 && n < 10, "Need to be a valid number in 0-9 range").TryShow(out var input))
+            {
+                if (!_fingerprintSensor.TrySetComparisonLevel(byte.Parse(input.ToString())))
+                {
+                    MessageBox.ErrorQuery("Comparison Level", "Can't set comparison level", "Ok");
+                }
+            }
+
+            UpdateComparisonLevel();
+        }
+
+        private void DeleteAFingerprint_Clicked()
+        {
+            if (new EntryDialog("User id", i => int.TryParse(i.ToString(), out var n), "Need to be a valid user id").TryShow(out var input))
+            {
+                if (!_fingerprintSensor.DeleteUser(ushort.Parse(input.ToString())))
+                {
+                    MessageBox.ErrorQuery("Delete User", "Can't delete user, check user id", "Ok");
+                }
+            }
+
+            UpdateUserCount();
+        }
+
+        private void SleepButton_Clicked()
+        {
+            var window = new SleepDisplay(_fingerprintSensor);
+
+            Application.Run(window);
+        }
+
+        private void ClearFingerprintsButton_Clicked()
+        {
+            if (!_fingerprintSensor.DeleteAllUsers())
+            {
+                MessageBox.ErrorQuery("Delete All Users", "Can't delete all user", "Ok");
+            }
+        }
+
+        private void AddFingerprintButton_Clicked()
+        {
+            if (new EntryDialog("User id", i => ushort.TryParse(i.ToString(), out var n), "Need to be a valid user id").TryShow(out var input))
+            {
+                var dialog = new FingerprintDialog("Add Fingerprint", "Can't add fingerprint, try to place your finger flat on the sensor");
+
+                Task.Run(() =>
+                {
+                    switch (_fingerprintSensor.AddFingerprint(ushort.Parse(input.ToString()), UserPermission.Level1))
+                    {
+                        case ResponseType.Success:
+                            dialog.Cancel();
+
+                            Application.MainLoop.Invoke(() => MessageBox.Query("Add Fingerprint", "Successfully added fingerprint", "Ok"));
+
+                            break;
+                        case ResponseType.Full:
+                            dialog.ErrorMessage = "Sensor full, can't add more users";
+
+                            dialog.CancelAndShowError();
+
+                            break;
+                        case ResponseType.NoUser:
+                            dialog.ErrorMessage = "Can't add fingerprint, invalid id";
+
+                            dialog.CancelAndShowError();
+
+                            break;
+                        case ResponseType.FingerOccupied:
+                            dialog.ErrorMessage = "Can't add fingerprint, finger already registered";
+
+                            dialog.CancelAndShowError();
+
+                            break;
+                        case ResponseType.UserOccupied:
+                            dialog.ErrorMessage = "Can't add fingerprint, id already used";
+
+                            dialog.CancelAndShowError();
+
+                            break;
+                        default:
+                            dialog.CancelAndShowError();
+                            break;
+                    }
+                });
+
+                dialog.Show();
+
+                UpdateUserCount();
+            }
+        }
+
+        private void ReadFingerprintButton_Clicked()
+        {
+            var dialog = new FingerprintDialog("Read Fingerprint", "Can't read fingerprint, try to place your finger flat on the sensor");
+
+            (ushort userID, UserPermission permission) userInfo = default;
+
+            Task.Run(() =>
+            {
+                if (_fingerprintSensor.TryComparison1N(out userInfo))
+                {
+                    dialog.Cancel();
+                }
+                else
+                {
+                    dialog.CancelAndShowError();
+                }
+            });
+
+            dialog.Show();
+
+            if (userInfo != default)
+            {
+                MessageBox.Query("Read Fingerprint", $"Successfully read fingerprint\n\nUser ID: {userInfo.userID}\nPermissions: {userInfo.permission}\n ", "Ok");
+            }
+        }
+
+        private void UserCountButton_Clicked()
+        {
+            UpdateUserCount();
+        }
+        private void WriteOut(string text)
+        {
+            Task.Run(() =>
+            {
+                lock (_outputFileLock)
+                {
+                    File.AppendAllText(OutputFilePath, text);
+                }
+            });
+        }
+
+        private void ChangeConfig()
+        {
+            File.Delete(SettingsFilePath);
+
+            Application.Run(new SettingsDisplay());
+
+            InitSensor();
+
+            UpdateSerialPort();
+        }
+
+        private void Quit_Clicked()
+        {
+            Application.RequestStop();
+        }
+    }
+}

WaveshareUARTFingerprintSensor.Sample/WaveshareUARTFingerprintSensor.Sample.csproj

@@ -27,6 +27,8 @@
     <IsWebBootstrapper>false</IsWebBootstrapper>
     <UseApplicationTrust>false</UseApplicationTrust>
     <BootstrapperEnabled>true</BootstrapperEnabled>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -48,6 +50,9 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="NStack, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\packages\NStack.Core.0.14.0\lib\netstandard2.0\NStack.dll</HintPath>
+    </Reference>
     <Reference Include="Swan, Version=3.0.0.0, Culture=neutral, processorArchitecture=MSIL">
       <HintPath>..\packages\Unosquare.Swan.3.0.0\lib\net461\Swan.dll</HintPath>
     </Reference>
@@ -55,8 +60,21 @@
       <HintPath>..\packages\Unosquare.Swan.Lite.3.0.0\lib\net461\Swan.Lite.dll</HintPath>
     </Reference>
     <Reference Include="System" />
+    <Reference Include="System.Buffers, Version=4.0.3.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Buffers.4.5.1\lib\net461\System.Buffers.dll</HintPath>
+    </Reference>
     <Reference Include="System.Core" />
     <Reference Include="System.Drawing" />
+    <Reference Include="System.Memory, Version=4.0.1.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Memory.4.5.4\lib\net461\System.Memory.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Numerics" />
+    <Reference Include="System.Numerics.Vectors, Version=4.1.4.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Numerics.Vectors.4.5.0\lib\net46\System.Numerics.Vectors.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Runtime.CompilerServices.Unsafe, Version=4.0.4.1, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Runtime.CompilerServices.Unsafe.4.5.3\lib\net461\System.Runtime.CompilerServices.Unsafe.dll</HintPath>
+    </Reference>
     <Reference Include="System.ServiceProcess" />
     <Reference Include="System.ValueTuple, Version=4.0.3.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
       <HintPath>..\packages\System.ValueTuple.4.5.0\lib\net47\System.ValueTuple.dll</HintPath>
@@ -67,6 +85,9 @@
     <Reference Include="System.Data" />
     <Reference Include="System.Net.Http" />
     <Reference Include="System.Xml" />
+    <Reference Include="Terminal.Gui, Version=0.90.3.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\packages\Terminal.Gui.0.90.3\lib\net472\Terminal.Gui.dll</HintPath>
+    </Reference>
     <Reference Include="Unosquare.Raspberry.Abstractions, Version=0.4.1.0, Culture=neutral, processorArchitecture=MSIL">
       <HintPath>..\packages\Unosquare.Raspberry.Abstractions.0.4.1\lib\netstandard2.0\Unosquare.Raspberry.Abstractions.dll</HintPath>
     </Reference>
@@ -78,8 +99,14 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Views\DataDisplay.cs" />
+    <Compile Include="Views\EntryDialog.cs" />
+    <Compile Include="Views\FingerprintDialog.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Views\SettingsDisplay.cs" />
+    <Compile Include="Views\SleepDisplay.cs" />
+    <Compile Include="Views\TUIManager.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />
@@ -104,4 +131,11 @@
     </ProjectReference>
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Import Project="..\packages\Microsoft.NETFramework.ReferenceAssemblies.net472.1.0.0\build\Microsoft.NETFramework.ReferenceAssemblies.net472.targets" Condition="Exists('..\packages\Microsoft.NETFramework.ReferenceAssemblies.net472.1.0.0\build\Microsoft.NETFramework.ReferenceAssemblies.net472.targets')" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>Ce projet fait référence à des packages NuGet qui sont manquants sur cet ordinateur. Utilisez l'option de restauration des packages NuGet pour les télécharger. Pour plus d'informations, consultez http://go.microsoft.com/fwlink/?LinkID=322105. Le fichier manquant est : {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\packages\Microsoft.NETFramework.ReferenceAssemblies.net472.1.0.0\build\Microsoft.NETFramework.ReferenceAssemblies.net472.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.NETFramework.ReferenceAssemblies.net472.1.0.0\build\Microsoft.NETFramework.ReferenceAssemblies.net472.targets'))" />
+  </Target>
 </Project>

WaveshareUARTFingerprintSensor.Sample/packages.config

@@ -1,6 +1,14 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
+  <package id="Microsoft.NETFramework.ReferenceAssemblies" version="1.0.0" targetFramework="net472" developmentDependency="true" />
+  <package id="Microsoft.NETFramework.ReferenceAssemblies.net472" version="1.0.0" targetFramework="net472" developmentDependency="true" />
+  <package id="NStack.Core" version="0.14.0" targetFramework="net472" />
+  <package id="System.Buffers" version="4.5.1" targetFramework="net472" />
+  <package id="System.Memory" version="4.5.4" targetFramework="net472" />
+  <package id="System.Numerics.Vectors" version="4.5.0" targetFramework="net472" />
+  <package id="System.Runtime.CompilerServices.Unsafe" version="4.5.3" targetFramework="net472" />
   <package id="System.ValueTuple" version="4.5.0" targetFramework="net472" />
+  <package id="Terminal.Gui" version="0.90.3" targetFramework="net472" />
   <package id="Unosquare.Raspberry.Abstractions" version="0.4.1" targetFramework="net472" />
   <package id="Unosquare.Raspberry.IO" version="0.27.1" targetFramework="net472" />
   <package id="Unosquare.Swan" version="3.0.0" targetFramework="net472" />

WaveshareUARTFingerprintSensor/CommandType.cs

@@ -6,6 +6,9 @@ using System.Threading.Tasks;
 
 namespace WaveshareUARTFingerprintSensor
 {
+    /// <summary>
+    /// Command flags recognized by the sensor
+    /// </summary>
     public enum CommandType : byte
     {
         ModifySerialNumber = 0x08,

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

@@ -10,29 +10,67 @@ using System.Threading.Tasks;
 using Unosquare.RaspberryIO;
 using Unosquare.RaspberryIO.Abstractions;
 using Unosquare.WiringPi;
+using WaveshareUARTFingerprintSensor.Exceptions;
 
 namespace WaveshareUARTFingerprintSensor
 {
     public class FingerprintSensor : IDisposable
     {
-        public const string PrimarySerialPort = "/dev/ttyAMA0";
+        /// <summary>
+        /// Primary serial port on the RPI. <see href="https://www.raspberrypi.org/documentation/configuration/uart.md">Source</see>
+        /// </summary>
+        public const string PrimarySerialPort = "/dev/ttyAMA0";
+        /// <summary>
+        /// Secondary serial port on the RPI. <see href="https://www.raspberrypi.org/documentation/configuration/uart.md">Source</see>
+        /// </summary>
         public const string SecondarySerialPort = "/dev/ttyS0";
+        /// <summary>
+        /// Timeout used for the <see cref="SerialPort"/> I/O operations
+        /// </summary>
         public const int DefaultTimeout = 10_000;
+        /// <summary>
+        /// Maximum number of user that the sensor can store before throwing <see cref="ResponseType.Full"/>. It is also the ID of the last user
+        /// </summary>
+        public const int MaxUserID = 0xFFF;
+        /// <summary>
+        /// Internal buffer size
+        /// </summary>
+        public const int DataBufferSize = 4095;
 
+        /// <summary>
+        /// Thrown when "WAKE" pin is high, works like a press button. Can be used while the sensor is asleep
+        /// </summary>
         public event WakedEventHandler Waked;
+        /// <summary>
+        /// Delegate for the <see cref="Waked"/> event
+        /// </summary>
+        /// <param name="sender"></param>
         public delegate void WakedEventHandler(FingerprintSensor sender);
 
+        /// <summary>
+        /// <see cref="SerialPort"/> name/path used
+        /// </summary>
         public string PortName { get; }
 
+        /// <summary>
+        /// Mark the end of a command packet, usually the 8th byte
+        /// </summary>
         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();
 
+        /// <summary>
+        /// Create a new instance of <see cref="FingerprintSensor"/>, don't forget to call <see cref="Start"/> before using any command
+        /// </summary>
+        /// <param name="portName">A valid name/path to a serial port, see <see cref="PrimarySerialPort"/> and <see cref="SecondarySerialPort"/> for the RPI</param>
+        /// <param name="wakePin">WAKE <see cref="GpioPin"/> number, default is according to the sensor documentation wiring</param>
+        /// <param name="rstPin">RST <see cref="GpioPin"/> number, default is according to the sensor documentation wiring</param>
         public FingerprintSensor(string portName, int wakePin = 23, int rstPin = 24)
         {
             PortName = portName;
@@ -40,6 +78,9 @@ namespace WaveshareUARTFingerprintSensor
             _rstPinNumber = rstPin;
         }
 
+        /// <summary>
+        /// Start the sensor, initializing <see cref="BootstrapWiringPi"/>, the Gpio pins and the <see cref="SerialPort"/>
+        /// </summary>
         public void Start()
         {
             // Initialize Gpio
@@ -60,6 +101,11 @@ namespace WaveshareUARTFingerprintSensor
             _serialPort.Open();
         }
 
+        /// <summary>
+        /// Compute the checksum for a command packet: XOR of <see cref="byte"/> 1 to 5 (counting from 0)
+        /// </summary>
+        /// <param name="data">A command packet, usually 8 bytes</param>
+        /// <returns>The computed checksum, usually stored in the 6th <see cref="byte"/></returns>
         private byte ComputeChecksum(byte[] data)
         {
             byte checksum = 0;
@@ -72,8 +118,40 @@ namespace WaveshareUARTFingerprintSensor
             return checksum;
         }
 
+        /// <summary>
+        /// Compute the checksum for a data packet: XOR of <see cref="byte"/> 1 to (last - 2) (counting from 0)
+        /// </summary>
+        /// <param name="data">A data, not to be confused with a command packet</param>
+        /// <param name="length">Length of the data packet, should be 2 bytes less than data.Length</param>
+        /// <returns>The computed checksum, usually stored in the (last - 2)th byte</returns>
+        private byte ComputeChecksumData(byte[] data, int length)
+        {
+            byte checksum = 0;
+
+            for (int i = 1; i < length; i++)
+            {
+                checksum ^= data[i];
+            }
+
+            return checksum;
+        }
+
+        /// <summary>
+        /// Send an 8 <see cref="byte"/> command and read the response, can throw an <see cref="Exception"/>
+        /// </summary>
+        /// <param name="commandType">Command flag, see <see cref="CommandType"/></param>
+        /// <param name="first">First data <see cref="byte"/>, the 2th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="second">Second data <see cref="byte"/>, the 3th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="third">Third data <see cref="byte"/>, the 4th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="timeout">Timeout used for the <see cref="SerialPort"/>, default to <see cref="DefaultTimeout"/></param>
+        /// <returns>The 3 data <see cref="byte"/> from the response (2, 3 and 4), the third one is parsed as a <see cref="ResponseType"/></returns>
         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 };
 
@@ -89,7 +167,13 @@ namespace WaveshareUARTFingerprintSensor
                 _serialPort.Write(buffer, 0, buffer.Length);
 
                 // Response
-                _serialPort.Read(buffer, 0, buffer.Length);
+                int length = buffer.Length;
+                int offset = 0;
+                do
+                {
+                    int toRead = length - offset;
+                    offset += _serialPort.Read(buffer, offset, toRead);
+                } while (offset < length);
 
                 if (buffer[0] != PacketSeparator || buffer[7] != PacketSeparator || buffer[1] != (byte)commandType)
                 {
@@ -105,6 +189,15 @@ namespace WaveshareUARTFingerprintSensor
             return (buffer[2], buffer[3], (ResponseType)buffer[4]);
         }
 
+        /// <summary>
+        /// Send an 8 <see cref="byte"/> command and read the response, can throw an <see cref="Exception"/>
+        /// </summary>
+        /// <param name="commandType">Command flag, see <see cref="CommandType"/></param>
+        /// <param name="first">First data <see cref="byte"/>, the 2th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="second">Second data <see cref="byte"/>, the 3th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="third">Third data <see cref="byte"/>, the 4th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="timeout">Timeout used for the <see cref="SerialPort"/>, default to <see cref="DefaultTimeout"/></param>
+        /// <returns>The 3 data <see cref="byte"/> from the response (2, 3 and 4)</returns>
         private (byte first, byte second, byte third) SendAndReceiveRaw(CommandType commandType, byte first, byte second, byte third, int timeout = DefaultTimeout)
         {
             (byte f, byte s, ResponseType response) = SendAndReceive(commandType, first, second, third, timeout);
@@ -112,6 +205,16 @@ namespace WaveshareUARTFingerprintSensor
             return (f, s, (byte)response);
         }
 
+        /// <summary>
+        /// Send an 8 <see cref="byte"/> command and read the response without throwing an <see cref="Exception"/>
+        /// </summary>
+        /// <param name="commandType">Command flag, see <see cref="CommandType"/></param>
+        /// <param name="first">First data <see cref="byte"/>, the 2th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="second">Second data <see cref="byte"/>, the 3th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="third">Third data <see cref="byte"/>, the 4th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="response">The response as returned by <see cref="SendAndReceive(CommandType, byte, byte, byte, int)"/></param>
+        /// <param name="timeout">Timeout used for the <see cref="SerialPort"/>, default to <see cref="DefaultTimeout"/></param>
+        /// <returns>true if successful, false otherwise</returns>
         private bool TrySendAndReceive(CommandType commandType, byte first, byte second, byte third, out (byte first, byte second, ResponseType responseType) response, int timeout = DefaultTimeout)
         {
             try
@@ -126,8 +229,18 @@ namespace WaveshareUARTFingerprintSensor
             }
 
             return true;
-        }
-
+        }
+
+        /// <summary>
+        /// Send an 8 <see cref="byte"/> command and read the response without throwing an <see cref="Exception"/>
+        /// </summary>
+        /// <param name="commandType">Command flag, see <see cref="CommandType"/></param>
+        /// <param name="first">First data <see cref="byte"/>, the 2th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="second">Second data <see cref="byte"/>, the 3th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="third">Third data <see cref="byte"/>, the 4th <see cref="byte"/> (counting from 0)</param>
+        /// <param name="response">The response as returned by <see cref="SendAndReceive(CommandType, byte, byte, byte, int)"/></param>
+        /// <param name="timeout">Timeout used for the <see cref="SerialPort"/>, default to <see cref="DefaultTimeout"/></param>
+        /// <returns>true if successful, false otherwise</returns>
         private bool TrySendAndReceiveRaw(CommandType commandType, byte first, byte second, byte third, out (byte first, byte second, byte third) response, int timeout = DefaultTimeout)
         {
             try
@@ -144,6 +257,45 @@ namespace WaveshareUARTFingerprintSensor
             return true;
         }
 
+        /// <summary>
+        /// Read a data packet
+        /// </summary>
+        /// <param name="length">The length of the data packet</param>
+        /// <param name="skipChecksum">An invalid checksum will throw an <see cref="Exception"/>, use this to ignore the checksum</param>
+        /// <returns></returns>
+        private byte[] ReadData(int length, bool skipChecksum = false)
+        {
+            byte first = (byte)_serialPort.ReadByte();
+
+            if (first != PacketSeparator)
+            {
+                throw new InvalidDataException("Invalid response from the sensor");
+            }
+
+            byte[] data = new byte[length];
+
+            int offset = 0;
+            do
+            {
+                int toRead = length - offset > DataBufferSize ? DataBufferSize : length - offset;
+                offset += _serialPort.Read(data, offset, toRead);
+            } while (offset < length);
+
+            byte checksum = (byte)_serialPort.ReadByte();
+            byte separator = (byte)_serialPort.ReadByte();
+
+            if (separator != PacketSeparator || (!skipChecksum && checksum != ComputeChecksumData(data, length)))
+            {
+                throw new InvalidDataException("Invalid checksum");
+            }
+
+            return data;
+        }
+
+        /// <summary>
+        /// Query the sensor serial number
+        /// </summary>
+        /// <returns></returns>
         public uint QuerySerialNumber()
         {
             (byte first, byte second, byte third) = SendAndReceiveRaw(CommandType.QuerySerialNumber, 0, 0, 0);
@@ -151,6 +303,11 @@ namespace WaveshareUARTFingerprintSensor
             return Utils.Merge(first, second, third);
         }
 
+        /// <summary>
+        /// Get the number of registered users (fingerprints)
+        /// </summary>
+        /// <param name="count">User count if the command is successful</param>
+        /// <returns></returns>
         public bool TryGetUserCount(out ushort count)
         {
             if (TrySendAndReceive(CommandType.QueryUserCount, 0, 0, 0, out var response, 1000))
@@ -167,14 +324,354 @@ namespace WaveshareUARTFingerprintSensor
             return false;
         }
 
+        /// <summary>
+        /// Add a fingerprint by sending three commands, with a delay between each to ensure the fingerprint is perfectly read
+        /// </summary>
+        /// <param name="userID">The id where to store the user (fingerprint)</param>
+        /// <param name="userPermission">The <see cref="UserPermission"/> to store</param>
+        /// <returns></returns>
+        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;
+        }
+
+        /// <summary>
+        /// Although there is the word 'Add' in the command (in the official doc), it does not currently add the fingerprint
+        /// in the captor storage for whatever reason
+        /// </summary>
+        /// <param name="userID"></param>
+        /// <param name="userPermission"></param>
+        /// <returns></returns>
+        public ResponseType AddFingerprintAndAcquireEigenvalues(ushort userID, UserPermission userPermission, out Span<byte> eigenvalues)
+        {
+            if (userID > MaxUserID)
+            {
+                eigenvalues = Span<byte>.Empty;
+                return ResponseType.Full;
+            }
+
+            CommandType[] commands = { CommandType.AddFingerprint1, CommandType.AddFingerprint2 };
+            (byte idHigh, byte idLow) = Utils.Split(userID);
+
+            foreach (var command in commands)
+            {
+                if (TrySendAndReceive(command, idHigh, idLow, (byte)userPermission, out var loopResponse))
+                {
+                    if (loopResponse.responseType != ResponseType.Success)
+                    {
+                        eigenvalues = Span<byte>.Empty;
+                        return loopResponse.responseType;
+                    }
+                }
+                else
+                {
+                    eigenvalues = Span<byte>.Empty;
+                    return ResponseType.Timeout;
+                }
+
+                Thread.Sleep(50);
+            }
+
+            if (TrySendAndReceive(CommandType.AddAndAcquireFingerprint, 0, 0, 0, out var response))
+            {
+                if (response.responseType != ResponseType.Success)
+                {
+                    eigenvalues = Span<byte>.Empty;
+                    return response.responseType;
+                }
+
+                ushort length = Utils.Merge(response.first, response.second);
+
+                var data = ReadData(length);
+                eigenvalues = data.AsSpan(3);
+
+                return ResponseType.Success;
+            }
+            else
+            {
+                eigenvalues = Span<byte>.Empty;
+                return ResponseType.Timeout;
+            }
+        }
+
+        /// <summary>
+        /// Delete a user (fingerprint) from the sensor
+        /// </summary>
+        /// <param name="userID">A valid user (fingerprint) id</param>
+        /// <returns>true if successful, false otherwise</returns>
+        public bool DeleteUser(ushort userID)
+        {
+            (byte high, byte low) = Utils.Split(userID);
+
+            if (TrySendAndReceive(CommandType.DeleteUser, high, low, 0, out var response, 1000))
+            {
+                return response.responseType == ResponseType.Success;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Delete all users (fingerprints) from the sensor
+        /// </summary>
+        /// <returns>true if successful, false otherwise</returns>
+        public bool DeleteAllUsers()
+        {
+            if (TrySendAndReceive(CommandType.DeleteAllUsers, 0, 0, 0, out var response, 1000))
+            {
+                return response.responseType == ResponseType.Success;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Delete all users that match a specified <see cref="UserPermission"/>
+        /// </summary>
+        /// <param name="userPermission"></param>
+        /// <returns>true if successful, false otherwise</returns>
+        public bool DeleteAllUsersWithPermission(UserPermission userPermission)
+        {
+            if (TrySendAndReceive(CommandType.DeleteAllUsers, 0, 0, (byte)userPermission, out var response, 1000))
+            {
+                return response.responseType == ResponseType.Success;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Read a fingerprint and check if it matches with the specified user
+        /// </summary>
+        /// <param name="userID">A registered user ID</param>
+        /// <returns>true if the fingerprint match</returns>
+        public bool Comparison11(ushort userID)
+        {
+            (byte high, byte low) = Utils.Split(userID);
+
+            if (TrySendAndReceive(CommandType.Comparison11, high, low, 0, out var response))
+            {
+                return response.responseType == ResponseType.Success;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Read a fingerprint and check if it match with any registered user
+        /// </summary>
+        /// <param name="userInfo">The matched user info</param>
+        /// <returns>true if the fingerprint match</returns>
+        public bool TryComparison1N(out (ushort userID, UserPermission permission) userInfo)
+        {
+            if (TrySendAndReceive(CommandType.Comparison1N, 0, 0, 0, out var response))
+            {
+                if (response.responseType != ResponseType.NoUser && response.responseType != ResponseType.Timeout)
+                {
+                    userInfo = (Utils.Merge(response.first, response.second), (UserPermission)response.responseType);
+
+                    return true;
+                }
+            }
+
+            userInfo = default;
+
+            return false;
+        }
+
+        /// <summary>
+        /// Get the stored <see cref="UserPermission"/> for a user
+        /// </summary>
+        /// <param name="userID">A registered user</param>
+        /// <param name="userPermission"></param>
+        /// <returns>true if the user exist, false otherwise</returns>
+        public bool TryQueryPermission(ushort userID, out UserPermission userPermission)
+        {
+            (byte high, byte low) = Utils.Split(userID);
+
+            if (TrySendAndReceive(CommandType.QueryPermission, high, low, 0, out var reponse, 1000))
+            {
+                if (reponse.responseType != ResponseType.NoUser)
+                {
+                    userPermission = (UserPermission)reponse.responseType;
+
+                    return userPermission != 0;
+                }
+            }
+
+            userPermission = default;
+
+            return false;
+        }
+
+        /// <summary>
+        /// Retrieve the comparison level used internally by the sensor to compare fingerprints
+        /// </summary>
+        /// <param name="comparisonLevel"></param>
+        /// <returns></returns>
+        public bool TryGetComparisonLevel(out byte comparisonLevel)
+        {
+            if (TrySendAndReceive(CommandType.ManageComparisonLevel, 0, 0, 1, out var response, 1000))
+            {
+                if (response.responseType == ResponseType.Success)
+                {
+                    comparisonLevel = response.second;
+
+                    return true;
+                }
+            }
+
+            comparisonLevel = default;
+
+            return false;
+        }
+
+        /// <summary>
+        /// Set the comparison level used internally by the sensor 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)
+            {
+                return false;
+            }
+
+            if (TrySendAndReceive(CommandType.ManageComparisonLevel, 0, comparisonLevel, 0, out var response, 1000))
+            {
+                return response.responseType == ResponseType.Success;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Read a fingerprint and retrieve it's raw image
+        /// </summary>
+        /// <param name="image"></param>
+        /// <returns>true if a valid fingerprint has been read</returns>
+        public bool TryAcquireImage(out byte[] image)
+        {
+             if (TrySendAndReceive(CommandType.AcquireImage, 0, 0, 0, out var response))
+             {
+                if (response.responseType == ResponseType.Success)
+                {
+                    var length = Utils.Merge(response.first, response.second);
+
+                    image = ReadData(length, skipChecksum: true);
+
+                    return true;
+                }
+             }
+
+            image = default;
+
+            return false;
+        }
+
+        /// <summary>
+        /// Read a fingerprint and retrieve the sensor computed eigenvalues
+        /// </summary>
+        /// <param name="eigenvalues"></param>
+        /// <returns>true if a valid fingerprint has been read</returns>
+        public bool TryAcquireEigenvalues(out Span<byte> eigenvalues)
+        {
+            if (TrySendAndReceive(CommandType.AcquireEigenvalues, 0, 0, 0, out var response))
+            {
+                if (response.responseType == ResponseType.Success)
+                {
+                    var length = Utils.Merge(response.first, response.second);
+
+                    eigenvalues = ReadData(length).AsSpan(3);
+
+                    return true;
+                }
+            }
+
+            eigenvalues = Span<byte>.Empty;
+
+            return false;
+        }
+
+        /// <summary>
+        /// Retrieve the sensor computed eigenvalues from a registered user
+        /// </summary>
+        /// <param name="userID"></param>
+        /// <param name="eigenvalues"></param>
+        /// <param name="userPermission"></param>
+        /// <returns></returns>
+        public bool TryAcquireUserEigenvalues(ushort userID, out Span<byte> eigenvalues, out UserPermission userPermission)
+        {
+            (byte high, byte low) = Utils.Split(userID);
+
+            if (TrySendAndReceive(CommandType.AcquireEigenvaluesDSP, high, low, 0, out var response))
+            {
+                if (response.responseType == ResponseType.Success)
+                {
+                    var length = Utils.Merge(response.first, response.second);
+
+                    var data = ReadData(length);
+                    eigenvalues = data.AsSpan(3);
+                    userPermission = (UserPermission)data[2];
+
+                    return true;
+                }
+            }
+
+            userPermission = default;
+            eigenvalues = Span<byte>.Empty;
+
+            return false;
+        }
+
+        /// <summary>
+        /// Make the sensor sleep, in this mode the sensor use less power (&lt;16 µA) but won't answer commands until it is waked using <see cref="Wake"/>.
+        /// <para/>
+        /// You can know when to wake the sensor using the <see cref="Waked"/> event that is still triggered while asleep
+        /// </summary>
         public void Sleep()
         {
+            _sleeping = true;
             _rstPin.Write(GpioPinValue.Low);
         }
 
+        /// <summary>
+        /// Wake the sensor, do nothing if it was not sleeping
+        /// </summary>
         public void Wake()
         {
-            _rstPin.Write(GpioPinValue.High);
+            _sleeping = false;
+            _rstPin.Write(GpioPinValue.High);
+
+            // Needed after wake to really wake the sensor
+            // Because the first command always fail for whatever reason
+            TryGetUserCount(out var _);
         }
 
         private void OnWake()
@@ -185,6 +682,9 @@ namespace WaveshareUARTFingerprintSensor
             }
         }
 
+        /// <summary>
+        /// Dispose by disposing the <see cref="SerialPort"/> used
+        /// </summary>
         public void Dispose()
         {
             _serialPort.Close();

WaveshareUARTFingerprintSensor/Properties/AssemblyInfo.cs

@@ -5,12 +5,12 @@ using System.Runtime.InteropServices;
 // Les informations générales relatives à un assembly dépendent de
 // l'ensemble d'attributs suivant. Changez les valeurs de ces attributs pour modifier les informations
 // associées à un assembly.
-[assembly: AssemblyTitle("WaveshareUARTFingerprintSensor")]
-[assembly: AssemblyDescription("")]
+[assembly: AssemblyTitle("Waveshare UART Fingerprint Sensor (C)")]
+[assembly: AssemblyDescription("C# library for the Waveshare UART fingerprint sensor (C)")]
 [assembly: AssemblyConfiguration("")]
-[assembly: AssemblyCompany("")]
+[assembly: AssemblyCompany("Ilyx")]
 [assembly: AssemblyProduct("WaveshareUARTFingerprintSensor")]
-[assembly: AssemblyCopyright("Copyright ©  2020")]
+[assembly: AssemblyCopyright("")]
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
 

WaveshareUARTFingerprintSensor/ResponseType.cs

@@ -6,10 +6,16 @@ using System.Threading.Tasks;
 
 namespace WaveshareUARTFingerprintSensor
 {
+    /// <summary>
+    /// If available, it is the third byte from a response packet
+    /// </summary>
     public enum ResponseType : byte
     {
         Success = 0x00,
         Fail = 0x01,
+        /// <summary>
+        /// Sensor has exceeded maximum number of users (0xFFF)
+        /// </summary>
         Full = 0x04,
         NoUser = 0x05,
         UserOccupied = 0x06,

WaveshareUARTFingerprintSensor/UserPermission.cs

@@ -0,0 +1,12 @@
+namespace WaveshareUARTFingerprintSensor
+{
+    /// <summary>
+    /// Permission level stored on the sensor for each user, it does not have any direct signification
+    /// </summary>
+    public enum UserPermission : byte
+    {
+        Level1 = 1,
+        Level2 = 2,
+        Level3 = 3
+    }
+}

WaveshareUARTFingerprintSensor/Utils.cs

@@ -8,10 +8,41 @@ namespace WaveshareUARTFingerprintSensor
 {
     public static class Utils
     {
+        /// <summary>
+        /// Parse two <see cref="byte"/> to an <see cref="ushort"/> according to the sensor documentation
+        /// </summary>
+        /// <param name="high">Usually the first data <see cref="byte"/> from a response</param>
+        /// <param name="low">Usually the second data <see cref="byte"/> from a response</param>
+        /// <returns></returns>
         public static ushort Merge(byte high, byte low) => (ushort)(high << 8 | low);
+        /// <summary>
+        /// Parse threee <see cref="byte"/> to an <see cref="uint"/> according to the sensor documentation
+        /// </summary>
+        /// <param name="first">Usually the first data <see cref="byte"/> from a response</param>
+        /// <param name="second">Usually the second data <see cref="byte"/> from a response</param>
+        /// <param name="third">Usually the third data <see cref="byte"/> from a response</param>
+        /// <returns></returns>
         public static uint Merge(byte first, byte second, byte third) => (uint)(first << 16 | second << 8 | third);
 
+        /// <summary>
+        /// Split an <see cref="ushort"/> to two bytes according to the sensor documentation
+        /// </summary>
+        /// <param name="value"></param>
+        /// <returns>The first <see cref="byte"/> (high) and the second <see cref="byte"/> (low)</returns>
         public static (byte high, byte low) Split(ushort value) => ((byte)(value >> 8), (byte)(value & 0xFF));
+        /// <summary>
+        /// Split an <see cref="uint"/> to three bytes according to the sensor documentation
+        /// </summary>
+        /// <param name="value"></param>
+        /// <returns></returns>
         public static (byte first, byte second, byte third) Split(uint value) => ((byte)(value >> 16 & 0xFF), (byte)(value >> 8 & 0xFF), (byte)(value & 0xFF));
+
+        /// <summary>
+        /// Display an array in a standard format
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="arr"></param>
+        /// <returns>A <see cref="string"/> in the form: [ element1, element2, element3, ... ]</returns>
+        public static string ArrayDisplay<T>(T[] arr) => $"[ {string.Join(", ", arr)} ]";
     }
 }

WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.csproj

@@ -38,8 +38,21 @@
       <HintPath>..\packages\Unosquare.Swan.Lite.3.0.0\lib\net461\Swan.Lite.dll</HintPath>
     </Reference>
     <Reference Include="System" />
+    <Reference Include="System.Buffers, Version=4.0.3.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Buffers.4.5.1\lib\net461\System.Buffers.dll</HintPath>
+    </Reference>
     <Reference Include="System.Core" />
     <Reference Include="System.Drawing" />
+    <Reference Include="System.Memory, Version=4.0.1.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Memory.4.5.4\lib\net461\System.Memory.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Numerics" />
+    <Reference Include="System.Numerics.Vectors, Version=4.1.4.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Numerics.Vectors.4.5.0\lib\net46\System.Numerics.Vectors.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Runtime.CompilerServices.Unsafe, Version=4.0.4.1, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\packages\System.Runtime.CompilerServices.Unsafe.4.5.3\lib\net461\System.Runtime.CompilerServices.Unsafe.dll</HintPath>
+    </Reference>
     <Reference Include="System.ServiceProcess" />
     <Reference Include="System.ValueTuple, Version=4.0.3.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
       <HintPath>..\packages\System.ValueTuple.4.5.0\lib\net47\System.ValueTuple.dll</HintPath>
@@ -62,9 +75,11 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="CommandType.cs" />
+    <Compile Include="Exceptions\SensorStateException.cs" />
     <Compile Include="FingerprintSensor.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ResponseType.cs" />
+    <Compile Include="UserPermission.cs" />
     <Compile Include="Utils.cs" />
   </ItemGroup>
   <ItemGroup>

WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.nuspec

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<package >
+  <metadata>
+    <id>$id$</id>
+    <version>$version$</version>
+    <title>Waveshare UART Fingerprint Sensor</title>
+    <authors>Eveldee</authors>
+    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <license type="expression">MIT</license>
+    <projectUrl>https://github.com/Eveldee/WaveshareUARTFingerprintSensor</projectUrl>
+    <!-- <iconUrl>http://icon_url_here_or_delete_this_line/</iconUrl> -->
+    <description>C# library for the Waveshare UART fingerprint sensor (C)</description>
+    <releaseNotes>Initial version.</releaseNotes>
+    <copyright>$copyright$</copyright>
+    <tags>Fingerprint Sensor Waveshare UART</tags>
+  </metadata>
+</package>

WaveshareUARTFingerprintSensor/packages.config

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
+  <package id="System.Buffers" version="4.5.1" targetFramework="net472" />
+  <package id="System.Memory" version="4.5.4" targetFramework="net472" />
+  <package id="System.Numerics.Vectors" version="4.5.0" targetFramework="net472" />
+  <package id="System.Runtime.CompilerServices.Unsafe" version="4.5.3" targetFramework="net472" />
   <package id="System.ValueTuple" version="4.5.0" targetFramework="net472" />
   <package id="Unosquare.Raspberry.Abstractions" version="0.4.1" targetFramework="net472" />
   <package id="Unosquare.Raspberry.IO" version="0.27.1" targetFramework="net472" />