Hi everyone,
I need some help in converting BCD to Decimal using Visual Basic 6. I searched the internet for weeks now and couldn't find a code which would convert BCD to Decimal and vice versa. I need it because I need to convert the values of the frequencies after being read by FSUIPC (They are read in BCD) to decimal and then add or subtract according to a specific reading from the parallel port. Anyhow, Visual Basic 6 gives me the decimal representation of the BCD value and I found this article: http://electronicdesign.com/Article/Artfeed=Top20
where it states that the following equation or formula : dbcd = (m*9256 + I*516 + b*26 + cc)*6 + x
can be used to convert decimal to BCD. It gives the right answer up to 45. After 46, things start going wrong so in small words. It is not reliable enough.
Long story short, I wrote a pretty long code to do the conversion and it works nicely yet it is complicated and difficult to amend. So could any one help me?? is there a VB code such as the dec2bcd code in C++? or is there any equation that would perfectly work?
I appreciate your kind help and looking forward to hearing from you...anyone..
Thanks and buy
N.B: The long code is as follows, if anyone is interested
Option Explicit
'This program is for controlling COM1 Radio with two keys in the keyboard (Alt & Ctrl)
Private Sub Form_Load()
Dim dwResult As Long
Dim Comm1_Radio As Long
'Set COM1 Radio to 118.00Mhz using BCD of 1800 which is 6144 to set the Radio
'frequency as the last digit (1) is considered to be there already
Comm1_Radio = 6144
'Send frequency to Radio @ MSFS
Call FSUIPC_Write(&H311A, 2, VarPtr(Comm1_Radio), dwResult)
Call FSUIPC_Process(dwResult)
End Sub
Private Sub butOK_Click()
Unload frmMain
End Sub
Private Sub Form_Unload(Cancel As Integer)
FSUIPC_Close
End Sub
Private Sub Timer1_Timer()
Dim dwResult As Long
Dim Comm1_Radio As Long
Dim Modified_Radio As Long
'The 4 Values required at conversion
Dim val() As Long
ReDim val(4)
'Titles of the 4 Values, val(1), val(2), val(3) and val(4)
Dim i As Long
'Required integer (n) for the conversion in sequence
Dim n As Long
'Read the frequency and recorded as Comm1_Radio (BCD). To control it, we need to change it to Bin -> Dec (Each 4 bits)
'-> Change it -> Binary (Each digit) -> BCD again -> Send it to MSFS
If FSUIPC_Read(&H311A, 2, VarPtr(Comm1_Radio), dwResult) Then
If FSUIPC_Process(dwResult) Then
'Present Comm1_Radio in the following format
lblComm1_Radio.Caption = Format(Comm1_Radio, "0")
Else 'No reading
lblComm1_Radio.Caption = "Processing: " & ResultText(dwResult)
End If
Else 'No reading
lblComm1_Radio.Caption = "Reading: " & ResultText(dwResult)
End If
'Convert the value Comm1_Radio to Binary
lblbinary.Caption = DecimalToBinary(Comm1_Radio)
'Add either 2 or 3 0's to make the total 16 bit
If Len(lblbinary.Caption) = 13 Then
lblbinary.Caption = "000" & lblbinary.Caption
ElseIf Len(lblbinary.Caption) = 14 Then
lblbinary.Caption = "00" & lblbinary.Caption
End If
'Bits: 1, 5, 9 and 13
For n = 1 To 16 Step 4
'Take the following 3 bits after each of the bits mentioned above
lbldecimal.Caption = Mid(lblbinary.Caption, n, 4)
i = i + 1
'Change each of the values to Decimal
val(i) = BinaryToDecimal(lbldecimal.Caption)
Next n
'Put the 4 values togather as a number = the frequency in Decimal
lbldecimal1.Caption = val(1) & val(2) & val(3) & val(4)
'Check the input
Label8.Caption = Inp(&H60)
'Speed the change if the user keeps the same input
'Case 1 input(Increase COMM1 Standby Frequency)*******************************************************************
If Label8.Caption = 29 Then
Timer1.Interval = Timer1.Interval - 1
If Timer1.Interval < 1 Then
Timer1.Interval = 1
End If
'Icrease the lately converted value of COMM1 frequency by 2.5 kHz (Decimal)
lblModified_Radio.Caption = lblModified_Radio.Caption + 2.5
ElseIf Label8.Caption = 56 Then
Timer1.Interval = Timer1.Interval - 1
If Timer1.Interval < 1 Then
Timer1.Interval = 1
End If
lblModified_Radio.Caption = lblModified_Radio.Caption - 2.5
Else
Timer1.Interval = 50
End If
'Get red of the decimal point without rounding
Label9.Caption = CSng(lblModified_Radio.Caption)
'Convert each digit in the latest value to binary
For n = 1 To 4
Label11.Caption = Mid(Label9.Caption, n, 1)
If Label11.Caption = 0 Then
Label12(n - 1) = "0000"
Else
val(n) = DecimalToBinary(Label11.Caption)
Label12(n - 1).Caption = val(n)
If Len(Label12(n - 1).Caption) = 1 Then
Label12(n - 1).Caption = "000" & val(n)
ElseIf Len(Label12(n - 1).Caption) = 2 Then
Label12(n - 1).Caption = "00" & val(n)
ElseIf Len(Label12(n - 1).Caption) = 3 Then
Label12(n - 1).Caption = "0" & val(n)
End If
End If
Next n
'Record the Finally coverted value as one large binary value
Label10.Caption = Label12(0).Caption & Label12(1).Caption & Label12(2).Caption & Label12(3).Caption
'Convert that value to decimal to derive the BCD of the new frequency
Label14.Caption = BinaryToDecimal(Label10.Caption)
Comm1_Radio = Label14.Caption
'Send the new frequency to MSFS
Call FSUIPC_Write(&H311A, 2, VarPtr(Comm1_Radio), dwResult)
Call FSUIPC_Process(dwResult)
End Sub
'Converting Decimal to Binary
Public Function DecimalToBinary(ByVal pValue As Long) As String
Dim C As Byte
Dim SubValue As Long
Dim Value As String
On Error GoTo ErrorHandler
SubValue = (2 ^ 31) - 1
While SubValue > 0
If pValue - SubValue >= 0 Then
pValue = pValue - SubValue
Value = Value & "1"
Else
If val(Value) > 0 Then Value = Value & "0"
End If
SubValue = SubValue / 2
Wend
DecimalToBinary = Value
Exit Function
ErrorHandler:
DecimalToBinary = "0"
End Function
'Converting Binary to Decimal
Public Function BinaryToDecimal(ByVal pValue As String) As Long
Dim C As Integer
Dim PosValue As Long
Dim Value As Long
On Error GoTo ErrorHandler
PosValue = 1
For C = Len(pValue) To 1 Step -1
If Mid(pValue, C, 1) = "1" Then Value = Value + PosValue
PosValue = PosValue * 2
Next
BinaryToDecimal = Value
Exit Function
ErrorHandler:
BinaryToDecimal = 0
End Function
