VB 2008 Atmel μC and PC via RS232/Tank monitoring

Question

0.00/5 (No votes)

See more:

Hi all,i'm asking you a question for first time.
I'm new in VB and i want to connect an Atmel with a PC via rs232,i have also installed the NI Measurement Components into my Visual Studio 2008.
The atmel is sending the value that it is reading from ADC port thru is UART port "Print Value". (i don't send chr(13)-CR)
My code in VB reads correctly the data from COM and print them into a text box.
How can i use these data in order to use them into the tank1.value=integer ?
i have try many conversions but nothing.

Imports System.IO.Ports.SerialPort
Public Class Form1

Public Delegate Sub myDelegate()

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

If SerialPort1.IsOpen Then
SerialPort1.Close()
End If

Try
With SerialPort1
.PortName = "Com4"
.BaudRate = 9600
.Parity = IO.Ports.Parity.None
.DataBits = 8
.StopBits = IO.Ports.StopBits.One
.ReceivedBytesThreshold = 1
End With

SerialPort1.Open()

Catch ex As Exception
End Try

End Sub

Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing

Try
SerialPort1.Close()
Catch ex As Exception
MsgBox(ex.ToString)
End Try

End Sub

Private Sub DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) _
Handles SerialPort1.DataReceived
TextBox1.Invoke(New myDelegate(AddressOf updateTextBox), New Object() {})
End Sub

Public Sub updateTextBox()
Dim tankval As integer
tankval = AscW(CChar(SerialPort1.ReadExisting))
With TextBox1
.Font = New Font("Garamond", 12.0!, FontStyle.Bold)
.AppendText(SerialPort1.ReadExisting)
.ScrollToCaret()
Tank1.Value = tankval
TextBox2.Text = tankval
End With
End Sub

End Class

Posted 18-Dec-09 9:20am

aparis

Add a Solution

4 solutions

Solution 4

You really helped find the error,the transmited value need a line feed chr(10) and in VB must be "tankval=Integer.Parse(SerialPort1.ReadLine.Trim())".
thank you very much for your help ! :-D :-D :-D

Posted 18-Dec-09 11:35am

aparis

Updated 18-Dec-09 12:03pm

v2

Solution 3

Your problem is this line:

tankval = AscW(CChar(SerialPort1.ReadExisting))

ReadExisting() returns a string and you are converting it to a character and then converting it to a string.

If you are sure you only have one message you can do this:

tankval = Integer.Parse(SerialPort1.ReadExisting().Trim())

If not you may consider using String.Split() or some other way to get the individual values out of the return string.

BTW- It's generally not good form to do so much processing in the event handler, but that's a whole different question.

Posted 18-Dec-09 11:19am

Rick Shaub

Solution 2

the integer.parse() method is very close to succeed,first hit was displayed,but after that the application stops and i get an error "Input string was not in a correct format."
data are not in line.In hyperterminal i get data by rows without need to send CR.I tried with chr(10) linefeed and chr(13) carriage return and faced the same error.
the atmel is programmed in BASCOM,it just send any data with the PRINT command,i add the chars 10 & 13 near my value.i'm comfused.

Posted 18-Dec-09 11:03am

aparis

Updated 18-Dec-09 11:12am

v2

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Rick Shaub · Accepted Answer · 2009-12-18T10:26:00

You can use the Integer.Parse() method. However, You want to make sure to only use the part of the string that contains 1 representation of an integer. If you have several together in a row you get an exception or possibly parse the wrong value. Is this data terminated with a linefeed or carriage return or delimited? If so, you can use SerialPort.ReadLine() to get one line at a time. ReadExisting() is not a great function because it can return partial messages or no message at all.

VB 2008 Atmel μC and PC via RS232/Tank monitoring

4 solutions

Solution 4

Solution 3

Solution 2

Solution 1

Add your solution here

Preview 0

Existing Members

...or Join us