Splitting data received from Arduino - vb.net

Question

I am new to vb and I'm trying to split serial data received from the Arduino board on Visual Basic. I've watched and followed tutorials online that outputs all the serial data in one textbox and it works. But now i need to split the data into textboxes that correspond to the sensor (i have 5 sensors).
I've tried using .Split and arrays to split and then store the data before moving it to the corresponding textbox but it doesn't work.
Appreciate all the help I can get
Dim receivedData As String = ""
Private Sub AirQuality_Load(sender As Object, e As EventArgs) Handles Me.Load
GetSerialPortNames()
Timer1.Enabled = False
txtPmax.Text = 14.7
txtPmin.Text = 10
txtO2max.Text = 21
txtO2min.Text = 15
txtCO2.Text = 1000
txtP25.Text = 25
txtP10.Text = 50
txtCO.Text = 35
End Sub
Sub GetSerialPortNames()
' Show all available COM ports.
For Each sp As String In My.Computer.Ports.SerialPortNames
cbCOMPort.Items.Add(sp)
Next
cbCOMPort.SelectedIndex = 0
End Sub
Private Sub btnConnect_Click(sender As Object, e As EventArgs) Handles btnConnect.Click
Try
If (btnConnect.Text = "Connect") Then
If (cbCOMPort.Text <> "") Then
'Open Serial Port
SerialPort1.Close()
SerialPort1.PortName = cbCOMPort.Text
SerialPort1.BaudRate = 9600
SerialPort1.DataBits = 8
SerialPort1.Parity = Parity.None
SerialPort1.StopBits = StopBits.One
SerialPort1.Handshake = Handshake.None
SerialPort1.Encoding = System.Text.Encoding.Default 'very important!
SerialPort1.ReadTimeout = 10000
SerialPort1.Open()
btnConnect.Text = "Dis-connect"
Timer1.Enabled = True
btnUpdate.PerformClick()
Else
MsgBox("Select a COM port first")
End If
Else
SerialPort1.Close()
btnConnect.Text = "Connect"
Timer1.Enabled = False
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Function ReceiveSerialData() As String
Dim Incoming As String
Dim Array() As String
Incoming = SerialPort1.ReadExisting
Array = Split(Incoming, ";")
Pactual.Text = Array(0)
O2actual.Text = Array(1)
COactual.Text = Array(2)
CO2actual.Text = Array(3)
P25actual.Text = Array(4)
P10actual.Text = Array(5)
txtUpdate.Text = Array(6)
End Function
Sub numberValidate()
Try
If (CDbl(txtPmax.Text) < CDbl(txtPmin.Text) Or (CDbl(txtO2max.Text) < CDbl(txtO2min.Text))) Then
MsgBox("Error. Must be numbers or Max < Min")
End If
Catch ex As Exception
MsgBox("Error. Must be numbers or Max < Min")
End Try
End Sub
Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
Static bFlash As Boolean
receivedData = ReceiveSerialData()
If receivedData IsNot Nothing Then
txtUpdate.Text = receivedData
' Warning in GUI
Dim bWar As Boolean = receivedData.Contains("--Pressure not OK--" Or "--CO2 not OK--" Or "--O2 not OK--")
If receivedData.Contains("--Pressure not OK--" Or "--CO2 not OK--" Or "--O2 not OK--") Then
bFlash = Not bFlash
If bFlash Then
txtUpdate.BackColor = Color.FromArgb(255, 0, 0)
Else
txtUpdate.BackColor = Color.FromArgb(255, 255, 255)
End If
Else
txtUpdate.BackColor = Color.FromArgb(255, 0, 255)
End If
If receivedData.Contains("--Condition: Normal--") Then
txtUpdate.BackColor = Color.FromArgb(255, 255, 255)
End If
End If
End Sub
Private Sub btnUpdate_Click(sender As Object, e As EventArgs) Handles btnUpdate.Click
Dim writeText As String
writeText = "<" & CDbl(txtPmax.Text).ToString("00.0") & CDbl(txtPmin.Text).ToString("00.0") & CInt(txtO2max.Text).ToString("00") & CInt(txtO2min.Text).ToString("00") & CInt(txtCO2.Text).ToString("0000") & ">"
txtUpdate.Text = writeText
SerialPort1.Write(writeText)
End Sub