Using the Arduino Microcontroller Board with C# and .NET

using System;

using System.ComponentModel;

using System.IO.Ports;

using System.Linq;

using System.Windows;

namespace WPFToArduino

{

/// <summary>

/// Interaction logic for MainWindow.xaml

/// </summary>

///

///

public partial class MainWindow : Window

{

private readonly SerialPort _port;

private string _lastData = "";

private bool _stopped = false;

public MainWindow()

{

InitializeComponent();

DataContext = new SerialDataViewModel();

SerialDataViewModel = DataContext as SerialDataViewModel;
// Set up the serial port communication with the Arduino on COM3 at 9600 baud

_port = new SerialPort("COM3") {BaudRate = 9600};
// hook up the event for receiving the data

_port.DataReceived += _port_DataReceived;

_port.Open();

}

public SerialDataViewModel SerialDataViewModel { get; set; }

private void StartConnectionToArduino()

{
// Signal the Arduino Board to start sending data

_port.Write("A");

}

private void EndConnectionToArduino()

{
// Signal the Arduino Board to stop sending data

_port.Write("B");

}

private void _port_DataReceived(object sender, SerialDataReceivedEventArgs e)

{

if (_stopped) return;

// Send data received from the Arduino to the Listbox on the UI thread

Application.Current.Dispatcher.BeginInvoke((Action) (() =>

{

string data = _port.ReadExisting();

_lastData += data;

string[] allData = _lastData.Split('\n');

_lastData = allData[allData.Length - 1];

foreach (var word in allData.Take(allData.Length - 1))

{

SerialDataViewModel.Items.Add(word);

}

}));

}

private void OnGoButtonClicked(object sender, RoutedEventArgs e)

{

StartConnectionToArduino();

}

private void StopButton_Click(object sender, RoutedEventArgs e)

{

EndConnectionToArduino();

}

private void Window_Closing(object sender, CancelEventArgs e)

{

_stopped = true;

_port.Close();

}

}

The Arduino Code

The Arduino code is written in a C like language and is extremely straightforward. If you know C#, then getting a handle on programming the Arduino is a no-brainer. Unlike C of yonder years ago, the Arduino library uses full english words in there functions and class types. Listing 2 shows the Arduino code for implementing the state diagram in Figure 2.

There are two must have functions for all arduino programs. There is a setup method where you put all your initialization code and there is aloop method that continues to execute your code in a loop. The loop method acts like the engine driving the state machine we put inside the loop. Our loop method will do several things. First it will read the state of the push button to see if it was pressed. Next it will read the next byte of serial data. If an 'A' was sent, then we will tell the arduino to set a flag to start reading input. if a 'B' was sent, we'll tell the Arduino to set a flag to stop reading input. If the push button was pressed and the input reading flag is set, then we'll write CAT to the serial port. We'll signal that something was written by turning the LED on.