vb串口通信程序源码

VB串口通信程序源码可以实现在计算机和硬件设备（如Arduino）之间进行数据的传输和通信。下面是一个简单的VB串口通信程序源码示例：

Imports System.IO.Ports

Public Class Form1
    Dim myPort As New SerialPort   ' 创建串口实例

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        myPort.BaudRate = 9600   ' 设置波特率
        myPort.PortName = "COM1"   ' 设置串口号
        myPort.DataBits = 8   ' 设置数据位
        myPort.Parity = Parity.None   ' 设置校验位
        myPort.StopBits = StopBits.One   ' 设置停止位
        myPort.Handshake = Handshake.None   ' 设置握手协议
        myPort.ReadTimeout = 1000   ' 设置读取超时时间
        myPort.WriteTimeout = 1000   ' 设置写入超时时间

        AddHandler myPort.DataReceived, AddressOf DataReceivedHandler   ' 添加数据接收处理程序
    End Sub

    Private Sub btnOpen_Click(sender As Object, e As EventArgs) Handles btnOpen.Click
        If myPort.IsOpen = False Then
            Try
                myPort.Open()   ' 打开串口
                btnOpen.Enabled = False
                btnClose.Enabled = True
                txtSend.Enabled = True
                btnSend.Enabled = True
            Catch ex As Exception
                MessageBox.Show("串口打开失败！" & ex.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try
        End If
    End Sub

    Private Sub btnClose_Click(sender As Object, e As EventArgs) Handles btnClose.Click
        If myPort.IsOpen = True Then
            myPort.Close()   ' 关闭串口
            btnOpen.Enabled = True
            btnClose.Enabled = False
            txtSend.Enabled = False
            btnSend.Enabled = False
        End If
    End Sub

    Private Sub btnSend_Click(sender As Object, e As EventArgs) Handles btnSend.Click
        If myPort.IsOpen = True Then
            Try
                myPort.WriteLine(txtSend.Text)   ' 向串口发送数据
            Catch ex As Exception
                MessageBox.Show("发送数据失败！" & ex.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try
        End If
    End Sub

    Private Sub DataReceivedHandler(sender As Object, e As SerialDataReceivedEventArgs)
        Dim receivedData As String = myPort.ReadLine()   ' 从串口读取数据
        MsgBox("接收到的数据：" & receivedData)
    End Sub
End Class

上述代码主要实现了串口的打开和关闭、发送和接收数据的功能。通过`SerialPort`类实例化`myPort`对象，设置相应的串口参数和事件处理程序。事件处理程序`DataReceivedHandler`会在接收到数据时被调用，并弹出消息框显示接收到的数据。