Hex problems

[torpkevuk]

Hi..

I'm having some trouble trying to send some information through to a controller connected to my serial port.

I'm trying to send an FF but its being received as a 3F

Heres how I've been sending it

Serialport1.Output(Chr(&HFF))

If I dont send it with the Chr() it comes out as 32 35 35 which is no good as my controller wont reply if its not in the format of FF

Any help anyone can give me would be greatly appreciated.

[torpkevuk]

I tried rewriting the code and using a different serial port ocx.. heres what i have

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
With SerialConnection1
.BaudRate = 9600
.PortName = "COM1"
.Open()
End With
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
SerialConnection1.Write(Chr(255))
End Sub

My port sniffer is still coming up with a 3F though

Not sure if this helps, but I did a search on google to see if anyone else had the same trouble as me, and came across this post http://www.vbip.com/forum/topic.asp?id=4428

[penagate]

How is SerialConnection1 declared? Is the paramater of the .Write method typed as a String?

[Madsdk]

How is SerialConnection1 declared? Is the paramater of the .Write method typed as a String?

Hi There,

Just having the exact same problem.
Here's the code, very simple!:
---------------------------
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

If SerialPort1.IsOpen = False Then
SerialPort1.Open()
End If

SerialPort1.Write(Chr(255))
-------------------------
The output gives in the port-monitor a "?" and hex-code 3F.
I need it to give the hex-stringoutput " AA AA 09 "
I found the vbTAB to give me the "09" part, similar to the dec.code for TAB.
Now the "AA" should be dec.170 similar to ª.

I've been dangling with this crap for two weeks now, trying so many combinations and so, only having found the "09"..

If anyone could have an idea of solving this - still simple problem, it'd be much appreciated.

By the way, I'm using vb 2005 B2

[penagate]

I don't the .NET equivalent for this function offhand but in VB I would use StrConv, since VB strings are Unicode and you look like you are sending ANSI.

SerialPort1.Write(StrConv(Chr$(&HAA) & Chr$(&HAA) & Chr$(&H09), vbFromUnicode))

[Madsdk]

I don't the .NET equivalent for this function offhand but in VB I would use StrConv, since VB strings are Unicode and you look like you are sending ANSI.

SerialPort1.Write(StrConv(Chr(&HAA) & Chr(&HAA) & Chr(&H09), vbFromUnicode))

It seems that the "vbFromUnicode" does not apply to the .net...
It only has types like lowercase, uppercase and so..

Any ideas? It seems to be totally impossible to find anything or anyone with similar problems.

[penagate]

You gotta know where to look

According to KB 311338:

Bytes = System.Text.Encoding.GetEncoding(1252).GetBytes(SomeString)

Now, what does the .Write method accept as a parameter?

[Madsdk]

It accepts .Write(buffer() As Byte, offset As integer, Count As Integer)
buffer: The byte array to which the output is written.

and ofcourse also a string..

[penagate]

OK, in that case it's much easier. Just chuck the whole load in a byte array.

' I need to learn how to initialise arrays in VB.NET :D
Dim chBuf(2) As Byte
chBuf(0) = &HAA
chBuf(1) = &HAA
chBuf(2) = &H09
 
SerialPort1.Write(chBuf, 0 , 3)

assuming that Count = length of transmission in bytes.

You may also need to add a terminating null character.

[Madsdk]

OK, in that case it's much easier. Just chuck the whole load in a byte array.

' I need to learn how to initialise arrays in VB.NET :D
Dim chBuf(2) As Byte
chBuf(0) = &HAA
chBuf(1) = &HAA
chBuf(2) = &H09
 
SerialPort1.Write(chBuf, 0 , 3)

assuming that Count = length of transmission in bytes.

You may also need to add a terminating null character.

WOW, it's that simple.! Now, i'm quite new to coding, so I guess I gotta learn to translate those - to me - cryptic help popups..!

Now what are you saying about that term. null char?

[penagate]

A null character is just a zero

Strings in pretty much all languages are null-terminated. Because they are (usually) variable in length, the null character is appended to signify the end of the string data. Otherwise, whatever function it was would keep on reading memory (thinking it was string data) until it chucked an access violation

I'm not sure whether you need to send terminating null characters in serial transmissions (I suspect you do), just in case here's how you do it.

' Still haven't found out how to initialise an array properly :)
Dim chBuf(3) As Byte
chBuf(0) = &HAA
chBuf(1) = &HAA
chBuf(2) = &H09
chBuf(3) = 0
 
' and then, the length is just increased by 1 byte
SerialPort1.Write(chBuf, 0, 4)

[penagate]

w00t, you learn something every day

Dim chBuf(3) As Byte = {&HAA, &HAA, &H09, 0}
SerialPort1.Write(chBuf, 0, 4)

[Madsdk]

w00t, you learn something every day

Dim chBuf(3) As Byte = {&HAA, &HAA, &H09, 0}
SerialPort1.Write(chBuf, 0, 4)

Man... you are sooo kind!! This is really appreciated!!!

What i'm using this for is a I/O interface card board thingy and it was sold with a sample software, but no source code.

Well.. the last thing i think i need is something like a "enter" or something.
If I paste the ª ª "tab" sequence in hyperterminal the unit responds with the status of the input lines. My port-monitor shows AA AA 09 and then makes a new line.

wonder what the difference from this is...

[penagate]

How to do a new line depends on the platform. On Windows and DOS it is CR plus LF (carriage return and line feed) and that is character codes 13 and 10 respectively. However on some platforms you can get away with just sending the carriage return character.

Try these:

Dim chBuf(5) As Byte = {&HAA, &HAA, &H09, 10, 13, 0}
' or
Dim chBuf(4) As Byte = {&HAA, &HAA, &H09, 13, 0}

and remember that the Count parameter takes the UBound of the array + 1, because the array is zero based