VB.net to Prop communication
Shawna
Posts: 508
Does anyone have any good links for VB.net tutorials? I want to write a quick debugging program to receive data from a Prop. I am using PST right now and I would like to arrange the data into a little more user friendly format for viewing. I am working on a quadcopter control board and the PST is not getting it done. I took 2 semesters of VB6 back in school but I am pretty rusty I found. Is there an easier language to play with? I found a tutorial on you tube for serial com ports that I followed and it works, but I am not sure how to break up the received data on the vb.net side. I need to start with the basics I think. VB for dummies maybe in my future, ha ha. I wouldn't mind playing with C a little since that can be used to program all kinds of micro controllers. Is C easier to learn than VB?
Thanks
Shawn
Thanks
Shawn
Comments
Shawn
DrAcula probably has done this. VB6 would be much easier for you I think and it has been done here somewhere. If not, I can dig out a VB6 program that uses the serial port from my backups.
Please don't start the C vs VB debate
What sort of data, and what does 'arrange' mean ?
Depending on exactly what that statement means, you could look along the lines of the basics that come with Open Office Spreadsheets etc.
A quick google gives this
[Solved] Macro to read serial port and write to OOo Calc
http://forum.openoffice.org/en/forum/viewtopic.php?t=30999
Another pathway, for long-graph multi-line style Data is to stream into a formatted .RAW file, which is the format used by LTSpice et al.
Then you load that file, using LTSpice as the Graphical viewer.
Thanks
Shawn
I could also help to integrate the Propellent Dll into your application which you might find to be useful.
Jeff T.
What is the Propellent Dll?
Shawn
Shawn
Yes it sure is whether your using C# or Vb .Net. This link has the Dll and documentation regarding the Propellent Library http://www.parallax.com/tabid/832/Default.aspx
If you are using the Proptool then you already have the DLL
Jeff T.
Read down to the very end of this and find PST.PX() and PST.PY()
A screen for 20 variables shouldn't be a problem.
Richard
PST.Methods:
The following are some of the more useful methods found in the Propeller Serial Terminal File (PST for short?)
[h=2]START[/h]The start method will be found in most objects as it is used to launch the object in a different cog. It is also used to pass I/O or configuration.
PST.start(9600) ‘ start serial terminal at 9600 baud
PST.start(12)
PST.start(my_variable,my_variable2)
[h=2]STOP[/h]The stop method stops the object and frees the cog.
[h=2] [/h][h=2]INIT[/h]The init method sets up variables for objects that don’t use their own cog. It is used instead of start in those instances.
(Some objects may require a call to init before calling start. Any necessary set-up calls will be clearly described in the object’s source file).
[h=2]STR [/h][h=2]The str method displays text or the contents of a variable or array.[/h]PST.str(string(“Display a line of text”))
PST.str(string(“Display a line of text with a carriage return”,13))
PST.str(my_multibyte_variable)
PST.str(@my_variable_array)
PST.str(@my_variable_array[X])
[h=2]
DEC [/h][h=2]The dec method display variables as a decimal numbers.[/h]PST.dec(my_variable)
[h=2]
HEX [/h][h=2]The hex method displays a variable in hexadecimal. [/h]The second item (2 in this example) tells how many places to display.
PST.hex(my_variable,2)
[h=2]
BIN [/h]The bin method displays a variable in binary.
The second item is the number of digits to
PST.bin ( some_variable, 8 )
[h=2]OUT (or TX)[/h]The PST.out (sometimes called .tx) method will be found in various display and communication objects to handle serial communications.
For video drivers out( ) should interpret the variable instead of displaying the character itself. For example: out ( $08 ) would cause a backspace, instead of displaying the box corner character.
[h=2]NEWLINE[/h]The PST.newline method sends a carriage return.
Same function as pst.out ( 13 ) or out ( $0D ).
As you can see there are a lot of useful methods in the Serial Terminal program. And, as your programs become more involved you will find this tool to be a life saver.
For control of the screen layout ASCII control codes can be defined and used with the Parallax Serial Terminal.
Define these in the CON section
HM = 1 'HM: HoMe cursor
PC = 2 'PC: Position Cursor in x,y
ML = 3 'ML: Move cursor Left
MR = 4 'MR: Move cursor Right
MU = 5 'MU: Move cursor Up
MD = 6 'MD: Move cursor Down
BP = 7 'BP: BeeP speaker
BS = 8 'BS: BackSpace
TB = 9 'TB: TaB
LF = 10 'LF: Line Feed
CE = 11 'CE: Clear to End of line
CB = 12 'CB: Clear lines Below
NL = 13 'NL: New Line
PX = 14 'PX: Position cursor in X
PY = 15 'PY: Position cursor in Y
CS = 16 'CS: Clear Screen
To use, simply add a line to your code like…
PST.CS clear the screen
PST.NL move to the next line
PST.PX(10) move the cursor to column 10
PST.PY(10) move the cursor to line 10
PST.TB move cursor to the next tab stop
Click the "Prefs..." button in Parallax Serial Terminal and then click the "Function" tab in the Preferences dialog box, you can view/select the ASCII control characters it recognizes.
I am still struggling with this guys and I thank you all for your input so far. I am way off on a tangent here, and off coarse from my original project which is the quadcopter. But everything is a learning process so I am going to continue on this vb.net thing. I have written a basic spin program to send 2 longs out the serial port any time an "a" is received on the Props Serial Port. This works well enough for now. Here is the code, it is very simple.
CON
_clkmode = xtal1 + pll16x
_xinfreq = 5_000_000
MHZ = 80
obj
PST : "Parallax Serial Terminal"
var
long IN
PUB Debug
PST.Start(115_200)
repeat
IN:=PST.CharIn
If In == "a"
PST.Bin(1,32)
PST.NewLine
PST.Bin(2,32)
Now, I realize that this is not a VB forum but you guys are very helpful. This is the code I have for VB and it works but it throws everything into 1 rich text box and for the life of me I can not figure out how to separate the data.
I can't even figure out how to manipulate this code to display it as integer instead of a string. I do not understand delegates and it seems like I have to do that in order to read the serial input buffer. I even added a button so that when it is pressed vb sends an "a" to the prop which tells the prop to send its data, and it works. How ever it still just dumps it into a rich text box. The rich text box is all I have on the form, but I tried to dump the receive buffer into a array and from there I was going to add more text boxes. I failed at the array and I am stuck. I posted a question on one of the VB forums and my lack of terminology and knowledge of VB sank me. I have attached my VB file if anyone is board and would be willing to look at it.
Thanks Shawn
Serial Com1 Test1 VB.zip
1) at the beginning
2) In the main form declare the serial port and also a couple of global arrays and also the sleep statement and a few global parameters for the serial port. (You can declare some of these in the object on the screen or in code)
Public Class Form1 Dim WithEvents SerialPortName As New IO.Ports.SerialPort ' generic serial port Public Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Integer) ' for sleep statements Dim InPacket(0 To 2000) As Byte ' Major bug with serial.write strings like chr(255) won't go out Dim OutPacket(0 To 2000) As Byte Public SerialPortFound As Boolean = True Public Baud As String Public ComPort As String3) When the form first loads, set some of these values
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Timer1.Interval = 150 ' check for new characters every 150ms ComPort = "COM1" ' can change later if needed Baud = 1152004) A useful routine to reset the propeller if you happen to be using the same port for downloading
Sub ResetPropeller() SerialPortName.PortName = ComPort SerialPortName.Open() SerialPortName.DtrEnable = False SerialPortName.DtrEnable = True ' toggle the dtr line SerialPortName.DtrEnable = False SerialPortName.Close() End SubAdd a timer, and the code from the form1 load will set it to check for port updates every n milliseconds (I set it at 150 milliseconds) and then call this routine to collect any bytes. This is for a simple terminal program - I think you have something similar already working adding things to a richtext box. Further down we can input the data into the array and feed it into other things such as a string, or convert it to data. (try typing "strings." and you can see all the things the strings class can do, like convert strings to numbers and vice versa)
Private Sub UpdateTerminal() Dim BytesToRead As Integer Dim i As Integer Dim Character As String ' called from the timer BytesToRead = SerialPortName.BytesToRead If BytesToRead > 2000 Then BytesToRead = 2000 SerialPortName.Read(InPacket, 0, BytesToRead) ' read in a packet For i = 1 To BytesToRead Character = Strings.Chr(InPacket(i - 1)) If Character <> Strings.Chr(10) Then ' otherwise double space RichTextBox8.AppendText(Character) ' add to the rich text box End If Next i End SubThis is an example of reading in some bytes. Borrowed from the catalina driver. Discard the bits you don't need. This "runs" a program on the propeller and so it is useful to see this happening. I've left in bits you won't need as it shows a method of collecting text that may not arrive in the time you expect it to, and moving that text from the input buffer into a string and then into a label on the screen. I think these are some of the processes you are looking to use. There are little tricks like "doevents" that force an update of the label as sometimes the data is actually in a textbox or a label but it isn't being refreshed.
Dim i As Integer Dim c As String Dim BytesToRead As Integer SerialPortName.BaudRate = 38400 ' catlyst2 talks at 38400 baud SerialPortName.Open() Label1.Text = "Running catlyst2.exe" System.Windows.Forms.Application.DoEvents() ' display on screen Sleep(4000) ' time to start up catalyst Label1.Text = "" Do If SerialPortName.BytesToRead = 0 Then Exit Do ' no more bytes BytesToRead = SerialPortName.BytesToRead If BytesToRead > 2000 Then BytesToRead = 2000 SerialPortName.Read(InPacket, 0, BytesToRead) ' read in a packet For i = 1 To BytesToRead c = Strings.Chr(InPacket(i - 1)) If Strings.Asc(c) > 32 Then Label1.Text += c Next i Loop System.Windows.Forms.Application.DoEvents() ' display on screen LineOfText = UCase(filename_noextension) + vbCr ' and run the program Call StringToPacket(LineOfText) ' talk to catalyst and run this program Label1.Text += LineOfText ' display on screen System.Windows.Forms.Application.DoEvents() ' display on screen SerialPortName.Close()Sometimes you might want to clear the input buffer
Sub ClearInputBuffer() ' eg for running pip no need to display all the background information Dim BytesToRead As Integer Dim i As Integer Dim Character As String If SerialPortFound = True Then Do If SerialPortName.BytesToRead = 0 Then Exit Do ' no more bytes BytesToRead = SerialPortName.BytesToRead If BytesToRead > 2000 Then BytesToRead = 2000 SerialPortName.Read(InPacket, 0, BytesToRead) ' read in a packet For i = 1 To BytesToRead Character = Strings.Chr(InPacket(i - 1)) 'Call DisplayCharacter(Character) Next i Loop End If System.Windows.Forms.Application.DoEvents() ' update the display End SubRoutine to test a port is actually available
Sub TestComPort() MsgBox("Com port " + ComPort + " Baud " + Baud + " trying to open...") Try SerialPortName.PortName = ComPort SerialPortName.BaudRate = Baud '38400 SerialPortName.Parity = IO.Ports.Parity.None ' no parity SerialPortName.DataBits = 8 ' 8 bits SerialPortName.StopBits = IO.Ports.StopBits.One ' one stop bit SerialPortName.Open() SerialPortName.Close() MsgBox("Success") Catch ex As Exception MsgBox("Fail") End Try End SubRoutine to display ports you actually have
Sub PortsAvailable() Dim ports As String() = SerialPort.GetPortNames() Dim PortsAvailable As String ' Display each port name to the console. Dim port As String For Each port In ports PortsAvailable += port + " " Next port MsgBox(PortsAvailable) End SubWarts and all, this is a routine to send a file to a propeller chip running Kyedos (a simple operating system). It uses the xmodem protocol and illustrates all the error checking and timing hacks needed to get reliable data comms. Maybe there are some bits of code you can use for other things?
Sub XModemKyeSend(ByRef FName As String, ByVal Delay1 As Integer) Dim Filenamepath As String Dim a, j, i As Integer Dim k As Integer Dim LineOfText As String Dim SerialString As String Dim Counter As Integer Dim ErrorString As String Dim Packetnumber As Integer Dim Checksum As Long Dim OnesComplement As Byte Dim ByteRead As Byte Dim BinaryFileLength As Long Dim BinaryFileCounter As Long Dim Percent As Single Dim ErrorCounter As Byte ' 0 to 10 Dim CPMFilename As String Dim Timeout As Boolean ProgressBar1.Maximum = 100 ProgressBar1.Minimum = 0 ' timer restart =true for sending via menu. False for auto send Filenamepath = FName Packetnumber = 1 ' 1 for the first packet (not zero) ' Try Dim Input As New FileStream(Filenamepath, FileMode.Open, FileAccess.Read) Dim br As New BinaryReader(Input) OpenSerialPort() ' open the serial port Label3.Text = "Error Count" Label2.Text = "0%" BinaryFileLength = br.BaseStream.Length() - 1 'i = Len(Filepath) + 1 + 1 ' eg c:\n8vem and a \ = 9 and 1 more for start of name only Call Get_CPM_Filename(Filenamepath, CPMFilename) CPMFilename = Strings.UCase(CPMFilename) LineOfText = "XMODEM R " + CPMFilename + vbCr Call StringToPacket(LineOfText) ' Call ClearInputBuffer() ' clear the buffer into the PC For i = 1 To Delay1 ' 50 for kyedos need to wait for kyedos to run the xmodem program Sleep(100) ' wait for the xmodem text to come back so the next one is a 21 Label3.Text = Str$(i) Call ClearInputBuffer() ' clear the buffer into the PC Next i Call ClearInputBuffer() ' clear the buffer into the PC Do SerialString = "" If SerialPortFound = True Then If SerialPortName.BytesToRead > 0 Then SerialPortName.Read(InPacket, 0, 1) ' get one byte SerialString = Chr(InPacket(0)) ' get a single character/string/byte End If End If If InPacket(0) = 21 Then ErrorString = "NAK" Exit Do ' got a ^U End If If SerialString <> "" Then 'LineOfText = SerialString 'Call TextLines(LineOfText) ' print it out unless it is a chr21 End If Counter = Counter + 10 Sleep(10) ' don't change this one - this is waiting for NAK Label1.Text = "Waiting for NAK to start" + Strings.Str(Counter) + "ms" ' display in milliseconds System.Windows.Forms.Application.DoEvents() ' update the label1 message ' add a counter and timeout if nothing If Counter > 5000 Then ErrorString = "Bypass wait for NAK - xmodem failed" Exit Do End If If ErrorString <> "" Then Exit Do Loop Label1.Text = ErrorString System.Windows.Forms.Application.DoEvents() ' update the label1 message Do ' act on each byte in the buffer array here XOut(0) = 1 'SOH ^A XOut(1) = Packetnumber OnesComplement = 255 - Packetnumber XOut(2) = OnesComplement Packetnumber = Packetnumber + 1 If Packetnumber > 255 Then Packetnumber = Packetnumber - 256 Checksum = 0 For i = 0 To 127 ' get 128 bytes from file If BinaryFileCounter <= BinaryFileLength Then ByteRead = br.ReadByte ' get a byte Else ByteRead = 26 ' pad with char 26 = hex 1A because hyperterm does this ? why but it works End If XOut(i + 3) = ByteRead Checksum = Checksum + ByteRead BinaryFileCounter = BinaryFileCounter + 1 Next ' create checksum Do If Checksum < 256 Then Exit Do ' work out checksum Checksum = Checksum - 256 Loop XOut(131) = Checksum Call OutputXout() System.Windows.Forms.Application.DoEvents() ' update the label Timeout = False Do k = 0 Do If SerialPortFound = True Then j = SerialPortName.BytesToRead End If If j >= 1 Then If SerialPortFound = True Then SerialPortName.Read(InPacket, 0, 1) ' get one byte End If Exit Do End If k += 1 If k > 5000 Then Timeout = True ' 5 second delay for timeout, must be more than the Rx side timeout Exit Do End If Sleep(1) ' 1ms delay Loop If InPacket(0) = 6 Then Exit Do ' remote got the packet so exit If InPacket(0) = 21 Then ' remote didn't get it so try sending again - does up to 10x ErrorCounter = ErrorCounter + 1 Call ClearInputBuffer() ' clear the input buffer to the PC Sleep(1000) ' let the remote get itself sorted before resending the packet Call OutputXout() ' resend the packet Label3.Text = "Nak: " + Strings.Str(ErrorCounter) System.Windows.Forms.Application.DoEvents() ' update the label End If If Timeout = True Then Label3.Text = "Timeout waiting for Ack" ErrorCounter = 20 'force an exit now System.Windows.Forms.Application.DoEvents() ' update the label End If If ErrorCounter >= 10 Then Exit Do ' more than 10 errors Loop If ErrorCounter >= 10 Then Label1.Text = "10 or more errors - aborting" Label2.Text = "0%" OutPacket(0) = 24 ' send a ^X cancel If SerialPortFound = True Then SerialPortName.Write(OutPacket, 0, 1) ' send 1 byte OutPacket(0) = 3 ' send a ^C SerialPortName.Write(OutPacket, 0, 1) ' send 1 byte End If Exit Do End If If BinaryFileCounter > BinaryFileLength Then Exit Do ' finish up Label1.Text = "Sent packet: " + Strings.Str(Packetnumber) + " = OK" Percent = BinaryFileCounter / BinaryFileLength Percent = Percent * 100 Percent = Int(Percent) Label2.Text = Strings.Str(Percent) + "%" ProgressBar1.Value = Percent Loop If ErrorCounter < 10 Then OutPacket(0) = 4 ' finish byte If SerialPortFound = True Then SerialPortName.Write(OutPacket, 0, 1) ' send 1 byte End If Label2.Text = "100%" Label1.Text = "Finished" ProgressBar1.Value = 0 'done Call StringToPacket(vbCrLf) ' back to kyedos End If Input.Close() Sleep(200) ' wait for next file System.Windows.Forms.Application.DoEvents() ' update the labels 'Catch ex As Exception ' Close() ' Label1.Text = Filenamepath + " not found" ' System.Windows.Forms.Application.DoEvents() ' update the labels ' Sleep(1000) ' so time to read message 'End Try SerialPortName.Close() ' close the serial port End Suband this is the routine to receive a file
Sub XModemKyeReceive(ByRef Filenamepath As String) ' pass full path eg C:\n8vem\FILE.TXT ' true for calls from menu bar, false for calls from pip 'Dim Filepath As String Dim FileName As String Dim XModemIn(0 To 131) As Byte Dim PacketSave(0 To 127) As Byte Dim i As Integer Dim LineOfText As String Dim Packetnumber As Integer Dim OnesComplement As Byte Dim BinaryFileLength As Long Dim ErrorCounter As Byte ' give up if gets to 10 Dim Checksum As Long Dim ValidPacket As Boolean Dim ErrorType As String Dim BytesToRead As Integer Dim RetryCounter As Integer OpenSerialPort() ' open the serial port Packetnumber = 1 ' I think it is 1 for the first packet Dim Output As New FileStream(Filenamepath, FileMode.Create, FileAccess.Write) Dim br As New BinaryWriter(Output) BinaryFileLength = br.BaseStream.Length() - 1 FileName = Strings.Mid(Filenamepath, 33) ' strip off the directory FileName = Strings.UCase(FileName) ' upper case 'LineOfText = Strings.Chr(13) 'Call StringToPacket(LineOfText) 'Sleep(300) ' to process the return ' run xmodem on the board 'System.Windows.Forms.Application.DoEvents() ' update the label1 message LineOfText = "XMODEM S " + FileName Call StringToPacket(LineOfText) ' start xmodem LineOfText = vbCrLf Call StringToPacket(LineOfText) ' send a return/LF System.Windows.Forms.Application.DoEvents() ' update the label1 message Sleep(3500) ' wait a 3.5 seconds for kyedos to run xmodem System.Windows.Forms.Application.DoEvents() ' update the label1 message Call ClearInputBuffer() ' clear the buffer into the PC OutPacket(0) = 21 ' send a NAK If SerialPortFound = True Then SerialPortName.Write(OutPacket, 0, 1) ' send it out End If Sleep(1000) ' wait for xmodem to put the line together Packetnumber = 1 Label2.Text = "" Do ' get first byte back ValidPacket = True ' start with true but errors could make it false RetryCounter = 0 Do Try If SerialPortFound = True Then SerialPortName.Read(InPacket, 0, 1) RetryCounter = 255 ' set so it restarts End If Catch RetryCounter += 1 Sleep(10) End Try Loop Until RetryCounter > 100 If RetryCounter <> 255 Then ValidPacket = False ErrorCounter = ErrorCounter + 1 ErrorType = "Serial port timeout" End If If InPacket(0) = 4 Then Label1.Text = "Finished transfer" Label2.Text = "100%" Exit Do End If If InPacket(0) = 1 Then ' valid packet so read the rest in XModemIn(0) = InPacket(0) ' already got the 1st byte so put it in xmodemin array If SerialPortFound = True Then For i = 1 To 131 SerialPortName.Read(InPacket, 0, 1) XModemIn(i) = InPacket(0) Next End If Label1.Text = "Packet " + Strings.Str(Packetnumber) ' display packet System.Windows.Forms.Application.DoEvents() ' update the label1 message End If If XModemIn(0) <> 1 And ValidPacket = True Then ' first number should be a 1 ValidPacket = False ErrorType = "First # not ^A SOH" ErrorCounter = ErrorCounter + 1 End If Do If Packetnumber < 256 Then Exit Do Packetnumber = Packetnumber - 256 Loop OnesComplement = 255 - Packetnumber ' ones complement must match If Packetnumber <> XModemIn(1) And ValidPacket = True Then ' packet number should be the next one ValidPacket = False ErrorType = "Packet number mismatch" ErrorCounter = ErrorCounter + 1 End If If XModemIn(2) <> OnesComplement And ValidPacket = True Then ValidPacket = False ErrorType = "Ones complement not valid" ErrorCounter = ErrorCounter + 1 End If Checksum = 0 For i = 3 To 130 Checksum = Checksum + XModemIn(i) Next Do If Checksum < 256 Then Exit Do ' work out checksum Checksum = Checksum - 256 Loop If Checksum <> XModemIn(131) And ValidPacket = True Then ValidPacket = False ErrorType = "Checksum invalid" ErrorCounter = ErrorCounter + 1 End If If ValidPacket = True Then ' got a good packet 'Sleep(50) ' 50 at 4800 wait a tick then acknowledge that got it ' no sleeps needed now with RetryCounter variable - that keeps trying till a byte arrives OutPacket(0) = 6 ' got the packet ^F=ACK If SerialPortFound = True Then SerialPortName.Write(OutPacket, 0, 1) ' send it out End If 'Sleep(50) ' 400 at 4800 wait for next packet to all come through - at least 200ms in pauses, plus the data, 200 does work but make it 400 For i = 3 To 130 PacketSave(i - 3) = XModemIn(i) ' read for save Next Output.Write(PacketSave, 0, 128) ' save 128 bytes Packetnumber = Packetnumber + 1 Else ' an error ' don't add one to packet number ' send a NAK ' try again Sleep(50) ' wait a tick then ask to send again OutPacket(0) = 21 ' NAK If SerialPortFound = True Then SerialPortName.Write(OutPacket, 0, 1) ' send it out End If Sleep(3000) ' wait for next packet to all come through - at least 200ms in pauses, plus the data, 200 does work but make it 400 End If Label3.Text = "Error: " + Strings.Str(ErrorCounter) + " " + ErrorType System.Windows.Forms.Application.DoEvents() ' update the label1 message If ErrorCounter >= 10 Then Exit Do Loop If ErrorCounter < 10 Then ' tell board got it all ok OutPacket(0) = 21 If SerialPortFound = True Then SerialPortName.Write(OutPacket, 0, 1) End If Sleep(100) ' expect back a 4, and then send a 6 OutPacket(0) = 6 If SerialPortFound = True Then SerialPortName.Write(OutPacket, 0, 1) End If Else Label1.Text = "File transfer failed" Label2.Text = "0%" System.Windows.Forms.Application.DoEvents() ' update the label1 message For i = 1 To 10 OutPacket(0) = 24 ' ^X cancel send 10 times If SerialPortFound = True Then SerialPortName.Write(OutPacket, 0, 1) ' send it out End If Sleep(200) Next i OutPacket(0) = 3 ' ^C If SerialPortFound = True Then SerialPortName.Write(OutPacket, 0, 1) ' send it out End If End If Output.Close() ' close the file SerialPortName.Close() End SubThat is a lot of info Dr_ Acula, that will take some time to process.
Thank You
Shawn
Note the baud rate is 38400 and the serial Object is Extended_FDSerial although you can change that to your preference.
VB code
Dim inbuff(80) As Byte Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click SerialPort1.DiscardOutBuffer() 'make sure our output buffer is flushed clear SerialPort1.Write("a") 'write "a" to port txt_out() 'call the display sub routine End Sub Private Sub txt_out() Dim value As UInt32 RichTextBox1.Clear() Threading.Thread.Sleep(45) 'give time for the data to arrive at the port buffer SerialPort1.Read(inbuff, 0, 80) 'read 80 bytes For idx = 0 To 76 Step 4 'parse the byte array back to longs value = BitConverter.ToUInt32(inbuff, idx) RichTextBox1.AppendText(value.ToString & vbCr) 'display Next End Sub