[RESOLVED] COM1 Problems

[Elios115]

i wrote this code to send a byte the the COM1 when an arrow is pressed on the keyboard

Option Explicit

Private Sub Command1_Click()
MSComm1.PortOpen = False
End
End Sub

Private Sub Form_Load()
MSComm1.CommPort = 1
MSComm1.Settings = "2400,N,8,1"
MSComm1.DTREnable = True
MSComm1.PortOpen = True
Dim oApp As Object
Dim oDoc As Object
Set oApp = CreateObject("Word.Application")
Set oDoc = oApp.documents.open("C:\Test.doc")
oApp.Visible = True
Set oDoc = Nothing
Set oDoc = Nothing

Me.KeyPreview = True
End Sub
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)

Select Case KeyCode
Case 37

MSComm1.Output = "11110010"
Text1.Text = 11110010


Case 38

MSComm1.Output = "11110001"
Text1.Text = 11110001
Text2.Text = MSComm1.OutBufferCount


Case 39

MSComm1.Output = "11111000"
Text1.Text = 11111000
Text2.Text = MSComm1.OutBufferCount


Case 40

MSComm1.Output = "11110100"
Text1.Text = 11110100
Text2.Text = MSComm1.OutBufferCount


End Select
End Sub

i tested the COM out buffer by using
Text2.Text = MSComm1.OutBufferCount

but it returned nottin which means the serial port isnt getting the byte!

can anyone help with this?

[Elios115]

any helpp

[dglienna]

What are you trying to send data to? Are you sure the parameters are correct?

[Elios115]

to the serial port to a microcontroller
yeah i think they r right

[Elios115]

what do u think?

[Elios115]

does anyone in this forum know what should be done to make this code work?

[namrekka]

MSComm1.Output = "11110010"

Do you mean that this is 1 Byte or 8 bytes?

[trisuglow]

With reference to post #1:

As I understand it, OutBufferCount returns the number of bytes in the output buffer. If it is zero this means the bytes have been sent .

[Elios115]

i m trying to send it as one byte, bit by bite

[CVMichael]

Do you mean that this is 1 Byte or 8 bytes?

That is 8 BYTES....

You cannot send one bit... you always send a byte (8 bits) at one time.

[Elios115]

so each 1 or 0 sent is a byte?
so how can i send a byte like 11110100?
mscomm.output="????"

[CVMichael]

Use this function like this:

mscomm.output = BinToByte("11110100")

Private Function BinToByte(ByVal Bin As String) As String
    Dim B As Byte, K As Long
    
    For K = 1 To 8
        If Mid$(Bin, K, 1) = "1" Then
            B = B Or 2 ^ (K - 1)
        End If
    Next K
    
    BinToByte = Chr(B)
End Function

[CVMichael]

Text2.Text = MSComm1.OutBufferCount

but it returned nottin which means the serial port isnt getting the byte!

can anyone help with this?

It's probably because you are not sending a lot of data, and it's sending the data right away. So when you call MSComm1.OutBufferCount, you always get 0 becasue the data is already sent.

Send a couple of kilo bytes (more than 1024 bytes), and then you will see that the MSComm1.OutBufferCount will slowly go to 0 as it's sending...

[Elios115]

man u r totally right , i sent out a sentence and it showed the buffer size.

so this function sends the input code (111101000) as bits

[CVMichael]

man u r totally right , i sent out a sentence and it showed the buffer size.

so this function sends the input code (111101000) as bits

Yup...

[Elios115]

thnks man

[Elios115]

but there s soemthing wrong cuz when i wrong sentence to send the outputbuffer size returned 0 no matter how long the sentence was

[CVMichael]

But did the data got sent or not ?

I still think it's sending fast, so by the time you read the output count, it's already sent...

A sentence is not much different then one byte, as I was saying bere send A LOT of data, over 1000 characters, even then it might be too fast.

[Elios115]

i tried to send 1000 characters but the count was still 0.
it worked when i just used the
MScomm.output="1001010100" so
is there any equivalent to send those bits?
11111000,11110100,11110010,11110001 without using the BinToByte function?

[moeur]

First of all there is a small error in Michael's code

'This line
' B = B Or 2 ^ (K - 1)
'Should be
B = B Or 2 ^ (8 - K)

Try this to send all four bytes at once

Option Explicit
 
Private Sub Command1_Click()
    Dim sdata As Variant
    sdata = Array("11111000", "11110100", "11110010", "11110001")
    MSComm1.Output = BinToByte(sdata)
End Sub
 
Private Function BinToByte(ByVal Bin As Variant) As Variant
    Dim B As Byte, K As Long, j As Long
    Dim s As String
    s = ""
    For j = LBound(Bin) To UBound(Bin)
        B = 0
        For K = 1 To 8
        If Mid$(Bin(j), K, 1) = "1" Then
            B = B Or 2 ^ (8 - K)
        End If
        Next K
        s = s & Chr(B)
    Next j
    BinToByte = s
End Function

msdn says that the output should be a variant.

[CVMichael]

First of all there is a small error in Michael's code

'This line
' B = B Or 2 ^ (K - 1)
'Should be
B = B Or 2 ^ (8 - K)

It's not really an error, it just depends on where you want the first byte to be, at the end or beginning... I don't think there are any rules on how binary is represented.

The Array thing can be made a little shorter with ParamArray:

Private Function BinToByte([b]ParamArray Bin() As Variant[/b]) As Variant
    Dim B As Byte, K As Long, j As Long
    Dim s As String
    s = ""
    
    For j = LBound(Bin) To UBound(Bin)
        B = 0
        
        For K = 1 To 8
            If Mid$(Bin(j), K, 1) = "1" Then
                B = B Or 2 ^ (8 - K)
            End If
        Next K
        
        s = s & Chr(B)
    Next j
    
    BinToByte = s
End Function
 
Private Sub Form_Load()
    Debug.Print BinToByte("11111000", "11110100", "11110010", "11110001")
End Sub

[Elios115]

guys the matter is that i need to send a byte (8 bits) to the serialport when i press one of the four arrows on the keyboard. this byte will control a device. so i just need to send 8 bits on each arrow press, thats it. i used the case with the keydown function for each of the four arrows to send a specific byte. did u get the idea? thx

[moeur]

I think we've shown you a couple ways to do this.
You need some method of determining that the bytes are arriving on the other end.

[dglienna]

As long as you are only using those four codes, just use this:

Select Case KeyCode
Case 37
  MSComm1.Output = "ò"
  Text1.Text = 11110010
Case 38
  MSComm1.Output = "ñ"
  Text1.Text = 11110001
  Text2.Text = MSComm1.OutBufferCount
Case 39
  MSComm1.Output = "ø"
  Text1.Text = 11111000
  Text2.Text = MSComm1.OutBufferCount
Case 40
  MSComm1.Output = "ô"
  Text1.Text = 11110100
  Text2.Text = MSComm1.OutBufferCount
End Select

Debug.Print BinToByte("11111000", "11110100", "11110010", "11110001")
øôòñ

[moeur]

I don't think there are any rules on how binary is represented.

Yes there are, just like representing decimal numbers, the most significant digit goes on the left, least significant on the right.

[Elios115]

i c so those characters are the equivalent byte i need to send. thats what i needed thx guys for ur help. you have the best forum

[Elios115]

but VB isnt accepting the characters! it is putting a question mark instead. any ideas plz

[dglienna]

You can also output chr$(248) to get 'ø', so just use the character codes.

248 ø
244 ô
242 ò
241 ñ