Hello and welcome to my article. Today, I’d like to show you how to perform basic serial port communication. It is quite easy, so let’s get started.
Open Visual Studio 2019 and create a new Console Application in either C# or VB.NET
As usual, let’s start by adding the necessary namespaces.
C#
using System; using System.IO.Ports; using System.Threading;
VB.NET
Imports System.IO.Ports Imports System.Threading
Add the modular variables that will be used throughout the program.
C#
private static bool blnCont; private static SerialPort spPort;
VB.NET
Shared blnCont As Boolean Shared spPort As SerialPort
blnCont is a Boolean flag that determines if we should continue trying to connect or not. spPort is the physical serial port object which we will work with.
Add the methods.
C#
public static string SetPortName(string strDefault)
{
string strPort;
Console.WriteLine("Available Ports:");
foreach (string s in SerialPort.GetPortNames())
Console.WriteLine("{0}", s);
Console.Write("Choose COM port (Default: {0}): ",
strDefault);
strPort = Console.ReadLine();
if (strPort == "" || !(strPort.ToLower()).StartsWith("com"))
strPort = strDefault;
return strPort;
}
public static int SetBaudRate(int intDefault)
{
string strRate;
Console.Write("Baud Rate(Default:{0}): ", intDefault);
strRate = Console.ReadLine();
if (strRate == "")
strRate = intDefault.ToString();
return int.Parse(strRate);
}
public static Parity SetParity(Parity pDefault)
{
string strParity;
Console.WriteLine("Available Parity options:");
foreach (string s in Enum.GetNames(typeof(Parity)))
Console.WriteLine("{0}", s);
Console.Write("Choose Parity (Default: {0}):",
pDefault.ToString(), true);
strParity = Console.ReadLine();
if (strParity == "")
strParity = pDefault.ToString();
return (Parity)Enum.Parse(typeof(Parity), strParity, true);
}
public static int SetDataBits(int intDefault)
{
string strBits;
Console.Write("Choose DataBits (Default: {0}): ",
intDefault);
strBits = Console.ReadLine();
if (strBits == "")
strBits = intDefault.ToString();
return int.Parse(strBits.ToUpperInvariant());
}
public static StopBits SetStopBits(StopBits sbDefault)
{
string strBits;
Console.WriteLine("Available StopBits options:");
foreach (string s in Enum.GetNames(typeof(StopBits)))
Console.WriteLine("{0}", s);
Console.Write("Choose StopBits (Default: {0}):",
sbDefault.ToString());
strBits = Console.ReadLine();
if (strBits == "")
strBits = sbDefault.ToString();
return (StopBits)Enum.Parse(typeof(StopBits), strBits, true);
}
public static Handshake SetHandshake(Handshake hsDefault)
{
string strHandShake;
Console.WriteLine("Available Handshake options:");
foreach (string s in Enum.GetNames(typeof(Handshake)))
Console.WriteLine("{0}", s);
Console.Write("Choose Handshake (Default: {0}):",
hsDefault.ToString());
strHandShake = Console.ReadLine();
if (strHandShake == "")
strHandShake = hsDefault.ToString();
return (Handshake)Enum.Parse(typeof(Handshake),
strHandShake, true);
}
public static void ReadMessage()
{
while (blnCont)
{
try
{
string strMessage = spPort.ReadLine();
Console.WriteLine(strMessage);
}
catch (TimeoutException)
{
}
}
}
VB.NET
Public Shared Function SetPortName(strDefault As String) _
As String
Dim strPort As String
Console.WriteLine("Available Ports:")
For Each s As String In SerialPort.GetPortNames()
Console.WriteLine("{0}", s)
Next
Console.Write("Choose COM port (Default: {0}): ", +_
strDefault)
strPort = Console.ReadLine()
If strPort = "" OrElse Not (strPort.ToLower()) _
.StartsWith("com") Then
strPort = strDefault
End If
Return strPort
End Function
Public Shared Function SetBaudRate(intDefault As Integer) _
As Integer
Dim strRate As String
Console.Write("Baud Rate(Default:{0}): ", intDefault)
strRate = Console.ReadLine()
If strRate = "" Then
strRate = intDefault.ToString()
End If
Return Integer.Parse(strRate)
End Function
Public Shared Function SetParity(pDefault As Parity) As Parity
Dim strParity As String
Console.WriteLine("Available Parity options:")
For Each s As String In [Enum].GetNames(GetType(Parity))
Console.WriteLine("{0}", s)
Next
Console.Write("Choose Parity (Default: {0}):", _
pDefault.ToString(), True)
strParity = Console.ReadLine(
If strParity = "" Then
strParity = pDefault.ToString()
End If
Return CType([Enum].Parse(GetType(Parity), strParity, _
True), Parity)
End Function
Public Shared Function SetDataBits(intDefault As Integer) _
As Integer
Dim strBits As String
Console.Write("Choose DataBits (Default: {0}): ", _
intDefault)
strBits = Console.ReadLine()
If strBits = "" Then
strBits = intDefault.ToString()
End If
Return Integer.Parse(strBits.ToUpperInvariant())
End Function
Public Shared Function SetStopBits(sbDefault As StopBits) _
As StopBits
Dim strBits As String
Console.WriteLine("Available StopBits options:")
For Each s As String In [Enum].GetNames(GetType(StopBits))
Console.WriteLine("{0}", s)
Next
Console.Write("Choose StopBits (Default: {0}):", _
sbDefault.ToString())
strBits = Console.ReadLine()
If strBits = "" Then
strBits = sbDefault.ToString()
End If
Return CType([Enum].Parse(GetType(StopBits), strBits, _
True), StopBits)
End Function
Public Shared Function SetHandshake(hsDefault As Handshake) _
As Handshake
Dim strHandShake As String
Console.WriteLine("Available Handshake options:")
For Each s As String In [Enum].GetNames(GetType(Handshake))
Console.WriteLine("{0}", s)
Next
Console.Write("Choose Handshake (Default: {0}):", _
hsDefault.ToString())
strHandShake = Console.ReadLine()
If strHandShake = "" Then
strHandShake = hsDefault.ToString()
End If
Return CType([Enum].Parse(GetType(Handshake), strHandShake, _
True), Handshake)
End Function
Public Shared Sub ReadMessage()
While blnCont
Try
Dim strMessage As String = spPort.ReadLine()
Console.WriteLine(strMessage)
Catch
End Try
End While
End Sub
We set the various properties of the serial port object here. We specify the parity, the baud rate, and so forth that are ultimately obtained from the user. Now, let’s put it all together in the main sub.
C#
public static void Main()
{
string strName;
string strMessage;
StringComparer scCompare = StringComparer.OrdinalIgnoreCase;
Thread tRead = new Thread(ReadMessage);
spPort = new SerialPort();
spPort.PortName = SetPortName(spPort.PortName);
spPort.BaudRate = SetBaudRate(spPort.BaudRate);
spPort.Parity = SetParity(spPort.Parity);
spPort.DataBits = SetDataBits(spPort.DataBits);
spPort.StopBits = SetStopBits(spPort.StopBits);
spPort.Handshake = SetHandshake(spPort.Handshake);
spPort.ReadTimeout = 500;
spPort.WriteTimeout = 500;
spPort.Open();
blnCont = true;
tRead.Start();
Console.Write("Enter Your Name: ");
strName = Console.ReadLine();
Console.WriteLine("Type QUIT to exit");
while (blnCont)
{
strMessage = Console.ReadLine();
if (scCompare.Equals("quit", strMessage))
blnCont = false;
else
spPort.WriteLine(String.Format("<{0}>: {1}",
strName, strMessage));
}
tRead.Join();
spPort.Close();
}
VB.NET
Public Shared Sub Main()
Dim strName As String
Dim strMessage As String
Dim scCompare As StringComparer = _
StringComparer.OrdinalIgnoreCase
Dim tRead As New Thread(AddressOf ReadMessage)
spPort = New SerialPort()
spPort.PortName = SetPortName(spPort.PortName)
spPort.BaudRate = SetBaudRate(spPort.BaudRate)
spPort.Parity = SetParity(spPort.Parity)
spPort.DataBits = SetDataBits(spPort.DataBits)
spPort.StopBits = SetStopBits(spPort.StopBits)
spPort.Handshake = SetHandshake(spPort.Handshake)
spPort.ReadTimeout = 500
spPort.WriteTimeout = 500
spPort.Open()
blnCont = True
tRead.Start()
Console.Write("Enter Your Name: ")
strName = Console.ReadLine()
Console.WriteLine("Type QUIT to exit")
While blnCont
strMessage = Console.ReadLine()
If scCompare.Equals("quit", strMessage) Then
blnCont = False
Else
spPort.WriteLine([String].Format("<{0}>: {1}", _
strName, strMessage))
End If
End While
tRead.Join()
spPort.Close()
End Sub
Conclusion
This was a lot of work! Hopefully, this article has shown you how to work with serial ports. Until next time, happy coding!
