[RESOLVED] Save Serial Data to Text File

[joko markono]

Hi Guys,

I'm trying to save data that i received from serial port into text file. So far, there is nothing in the file. What should i do?
Here is the code:

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick

        If SerialPort1.IsOpen Then
            Data_received &= SerialPort1.ReadExisting
            If Len(Data_received) > 0 Then
                ReceiveTextBox.Text = Data_received
                HistoryTextBox.Text = TimeOfDay.ToLongTimeString + " : " + Data_received + vbNewLine + HistoryTextBox.Text

                Dim writeFile As New System.IO.StreamWriter("Read.txt")
                writeFile.Write(SerialPort1.ReadExisting())
                writeFile.Close()
            End If
       End If

    End Sub

[OptionBase1]

Your writeFile command shouldn't be doing another serial port read. It should be writing the data already read from the Serial port that you've done in the code above it.

That being said, once you get that issue fixed, since your Data_received variable (which isn't declared in this block of code, so I'm assuming it is declared at the Form or Module level) is being concatenated rather overwritten, once data has been received the first time, in every execution of your Timer tick event after that your If statement will be True, even if no NEW data has been received, because Len(Data_received) will always be > 0. So with nothing new coming in to the serial port, your log file will continuously report the same data as being read, over and over again, as often as your Timer Tick event is raised.

[joko markono]

thanks, i manage to get the data into text file now with following code. but how can i arrange the data to be recorded to the next line every second? right now all new data on one single line in the text file.

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick

        If SerialPort1.IsOpen Then
            Data_received &= SerialPort1.ReadExisting


            If Len(Data_received) > 0 Then
                ReceiveTextBox.Text = Data_received
                HistoryTextBox.Text = TimeOfDay.ToLongTimeString + " : " + Data_received + vbNewLine + HistoryTextBox.Text
                Dim writeFile As New System.IO.StreamWriter("Read.txt")
                writeFile.Write(HistoryTextBox.Text)
                writeFile.Close()
              End If
       End If

[OptionBase1]

Use writeFile.WriteLine instead of writeFile.Write

[joko markono]

it doesn't work.

[OptionBase1]

Bummer.

[joko markono]

never mind, any idea how to stop the streamwriter?
something like Streamwriter.stop

[joko markono]

alright, manage to get everything in perfect order:

    Private Sub Log_button_Click(sender As Object, e As EventArgs) Handles Log_button.Click
        Log_button.BackColor = Color.LimeGreen
        StopLog_button.BackColor = Color.Transparent
        StopLog_button.Enabled = True
    End Sub
    Private Sub StopLog_button_Click(sender As Object, e As EventArgs) Handles StopLog_button.Click
        StopLog_button.BackColor = Color.Red
        Log_button.BackColor = Color.Transparent
        Log_button.Enabled = True
    End Sub

    'READ DATA STRING INPUT
    Dim Data_received As String

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick

        If SerialPort1.IsOpen Then
            Data_received &= SerialPort1.ReadExisting


            If Len(Data_received) > 0 Then
                ReceiveTextBox.Text = Data_received
                HistoryTextBox.Text = TimeOfDay.ToLongTimeString + " : " + Data_received + vbNewLine + HistoryTextBox.Text

                If Log_button.BackColor = Color.LimeGreen Then
                    Dim writeFile As New System.IO.StreamWriter("Read.txt", IO.FileMode.Append)
                    writeFile.Write(TimeOfDay.ToLongTimeString + " : " + Data_received + vbCrLf)
                    writeFile.Close()
                End If
       End If
    End Sub

[passel]

p.s. I see you posted while I was working on my post and examples...

If I wanted to write lines to a file, that is constantly open, written to, and closed, as you seem to want, I would use one of the IO.File methods.

Here's a brief example of one way.

Public Class Form1

  Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    Static counter As Integer
    counter += 1
    IO.File.AppendAllLines("c:\c\testAppend.txt", {String.Format("Line {0}", counter)})
  End Sub
End Class

That will open the file, append the string and automatically add the new line after the string is written.
The method actually takes a string array and will write each element of the array on a new line, which is why the {} is put around the string to turn it into a literal array, or anonymous array, or whatever the technical term should be.

The other obvious choice for a single string would be to use AppendAllText which expects a single string, and add the newline yourself.

Public Class Form1

  Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    Static counter As Integer
    counter += 1
    IO.File.AppendAllText("c:\c\testAppend.txt", String.Format("Line {0}{1}", counter, vbNewLine))
  End Sub
End Class

[joko markono]

Thanks for your idea. I will give a try.