求助各位大牛如何用VB2015写串口调试助手，自己写了一个，接受到的数据完全不一样，实在是没有头绪，查了好多资料还是不会，希望各位能给我一些帮助，谢谢
Option Strict Off
Imports System.IO.Ports
Public Class Form1
    Dim fx() As Byte
    Dim rc() As Byte
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        SerialPort1.BaudRate = 115200
        SerialPort1.PortName = "COM7"
        SerialPort1.DataBits = 8
        SerialPort1.StopBits = StopBits.One
        SerialPort1.Parity = Parity.None
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If Button1.Text = "打开串口“ Then
            SerialPort1.Open()
            Button1.Text = “关闭串口“
            Button2.Enabled = True
            Timer1.Enabled = True
        Else
            If SerialPort1.IsOpen Then SerialPort1.Close()
            Button1.Text = "打开串口“
            Timer1.Enabled = False
            Button2.Enabled = False
        End If
    End Sub
    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        Dim strrc As String
        Dim i As Integer
        Dim n As Integer
        n = SerialPort1.BytesToRead
        If n > 0 Then
            ReDim rc(n)
            strrc = ""
            For i = 1 To n
                rc(i) = SerialPort1.ReadByte
                strrc = Hex(rc(i)) & ""
            Next
            TextBox2.Text = strrc
        End If
    End Sub
这是我写的部分源码，不知道哪的问题？希望各位解答一下