Imports System
成都创新互联公司专注于上思企业网站建设,响应式网站设计,电子商务商城网站建设。上思网站建设公司,为上思等地区提供建站服务。全流程按需定制设计，专业设计，全程项目跟踪，成都创新互联公司专业和态度为您提供的服务
Imports System.IO.Ports
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'获取计算机有效串口
Dim ports As String() = SerialPort.GetPortNames() '必须用命名空间，用SerialPort,获取计算机的有效串口
Dim port As String
For Each port In ports
portnamebox.Items.Add(port) '向combobox中添加项
Next port
'初始化界面
'vb.net的串口接收数据要用到委托
Delegate Sub SetTextCallback(ByVal InputString As String) '声明一个委派类，并声明符合函数参数有一个，而其型态是字符串
Private Sub ShowString(ByVal comData As String)
txt_Re.Text = comData '将收到的数据入接收文字框中--- txt_Re.Text 是接收用的文本框
txt_Re.SelectionStart = txt_Re.Text.Length
txt_Re.ScrollToCaret()
End Sub
Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived‘自动接收事件
Dim inData As String = SerialPort1.ReadExisting
Dim d As New SetTextCallback(AddressOf ShowString)
Invoke(d, inData)
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click '发送指令
SerialPort1.Write("123")
End Sub
串口通信最终都是用二进制传输的，你用代码把二进制转化成十六进制就可以了。不需要额外设置。