Преобразование Int в массив байтов BCD

Джоэл ответил 2 сентября 2016 г.:

Public Shared Function ToBcd(ByVal pValue As Integer) As Byte()
    If pValue < 0 OrElse pValue > 99999999 Then Throw New ArgumentOutOfRangeException("value")

    Dim ret As Byte() = New Byte(3) {} 'All bytes are init with 0's

    For i As Integer = 0 To 3
      ret(i) = CByte(pValue Mod 10)
      pValue = Math.Floor(pValue / 10.0)
      ret(i) = ret(i) Or CByte((pValue Mod 10) << 4)
      pValue = Math.Floor(pValue / 10.0)
      If pValue = 0 Then Exit For
    Next

    Return ret
End Function

Хитрость здесь заключается в том, чтобы знать, что простое использование pValue /= 10 округлит значение, поэтому, если, например, аргумент равен «16», первая часть байта будет правильной, но результат деления будет 2 (как 1.6 будет округлено). Поэтому я использую метод Math.Floor.

Эта функция работает отлично, и я использую результат также в обратном порядке. Я пробовал несколько настроек, но что-то мне не хватает.

Мой вопрос:

Можно ли расширить 4 байта до 5 байт? Я использую его для преобразования частот в BCD. Некоторые радиолюбители запрашивают 5 байт.

Большое спасибо за ваш ответ, Джими.

Эта процедура работает, но в обоих случаях 4 байта + 5 байтов мой результат BCD неверен Результат без дробной части

4-байтовая функция всегда возвращает 4 байта.

5-байтовая функция

возвращает Nr-of-Bytes на основе входного значения. В этом случае возвращаемые байты должны быть вставлены в правый байт дополнительного 5-байтового массива? Фракция часть является проблемой. Возможно, для этого требуется 2. Вызов функции

На примере попробуйте получить правильный результат с обеими функциями: Входное значение: 439700,11

Я настраиваю одиночные возвращаемые значения с «0» впереди или сзади. Может быть, недостаточно.

Частоты: Гц x 1000 = кГц * 1000 = МГц * 1000 = ГГц С 4 байтами мы получаем 1 ГГц - 1. 999999,99

Данные 1 Данные 2 Данные 3 Данные 4 100/10 Гц 10/1 кГц 1 МГц/100 кГц 100/10 МГц 01 00 97 43 (439700,01 кГц) 50 00 01 07 (7100,50 кГц)

Пример: 4-байтовая функция Ввод: sfreq = "7000.00" sfreq = Replace(sfreq,.","") Результат: 00 70 00 00, что неверно Ввод: sfreq = "70000.00", Результат: 00 00 07 00, что неверно неправильно

4 байта

Dim sp As String = " " '1 пробел Dim ret As Byte() = New Byte(3) {} 'Все байты инициализируются с 0 Dim hfreq, sStr As String Dim ddouble As Double Dim ssfreq As String = "700000" ' мы всегда вводим десятичные дроби #####.00

hfreq = ""
ret = ToBcd(Val(ssfreq))
For i As Integer = 0 To 3
    sStr = Hex(ret(i))

    'just for testing 
    value = Val("&H" & sStr)
    value = Int(value / 16)
    MsgBox(value.ToString())

    'maybe byte values should adjusted based on the value  
    'or based on the total value string-Length

    If Len(sStr) = 1 Then
        If sStr = "0" Then
            sStr = sStr + "0"
        Else
            sStr = "0" & sStr
        End If
    End If
 hfreq = hfreq + sStr & sp  'sp = 1 space
 Next

 hfreq = Trim(hfreq)
 'the 4-Byte answer
 '00 70 00 00

 'convert to number
 Dim counter As Integer = 7
 sStr = Replace(hfreq, " ", "")
 Dim s1 As String = sStr
 sStr = ""
 While counter > 0    'read BCD/HEx from right to left
     sStr = sStr & Mid$(s1, counter, 2)
     counter = counter - 2
     If counter = 0 Then counter = 1
 End While

 value = Val(sStr) ' with the right result the value must be divided / 100

Я хотел бы использовать эти 2 функции, так как я считаю, что они быстрее, чем мои собственные функции. 10 лет назад я написал 2 функции для преобразования в BCD. Обе функции читают любое число и всегда возвращают правильный результат BCD. Я также использовал эти функции для объяснения логики преобразования в BCD.

Я уже не так молод, но все еще программирую для радиолюбителей вроде меня.

Здесь 2 функции sfreq должны быть «7000» или «7000.01», а не «7.000,01». Вы звоните: hfreq = SendHexStr(sfreq) Вы звоните: hfreq = SendHexStr4Byte(sfreq)

Private Sub InsertDec4Byte(ByVal frac)
    Dim dd As Double
    Dim freqfrac As String = frac
    If frac Then
        Dim f1, f2, h2 As Double
        'even 50    even
        dd = Val(freqfrac)
        f1 = Val(shex4(1))             '10
        f2 = Val(Mid(freqfrac, 1, 2)) '50
        If (dd Mod 10 = 0) Then
            '0.50
            f2 = f2 / 10                  '5
            h2 = f1 + f2
            If h2 < 10 Then
                shex4(1) = "0" & h2.ToString()       '15
            Else
                shex4(1) = h2.ToString()       '15
            End If
        Else
            '51 - Odd
            f2 = Val(Mid(freqfrac, 1, 1)) '5
            h2 = f1 + f2                  ' 10 + 5

            If h2 < 10 Then
                shex4(1) = "0" & h2.ToString()       '15
            Else
                shex4(1) = h2.ToString()       '15
            End If

            f2 = Val(Mid(freqfrac, 2, 1)) '1
            f2 = f2 * 10
            shex4(0) = f2                  '10 = 0.01

        End If
    End If
End Sub

'Hex 4 Byte
Private Function SendHexStr4Byte(ByVal hs)

    Dim sStr As String = ""
    Dim s1 As String = ""
    Dim freq As String = ""
    Dim freqfrac As String = ""
    Dim ppos As Integer = 0
    Dim frac As Boolean = False

    'fill the array with Hex '00'
    For i As Integer = 0 To 3
        shex4(i) = "00"
    Next

    freq = hs
    freq = Replace(freq, ",", ".")
    s1 = freq

    'copy the fraction part if any - 500.01 - 501.50
    ppos = InStr(1, freq, ".", CompareMethod.Text)
    If ppos > 0 Then
        'copy only the integer part as frequency
        s1 = Mid(s1, 1, ppos - 1)
        'the fraction part
        freqfrac = Mid(freq, ppos + 1, Len(freq) - ppos)

        'correct input error
        If Len(freqfrac) = 1 Then freqfrac = freqfrac & "0"
        If Len(freqfrac) = 0 Then freqfrac = freqfrac & "00"

        frac = Not frac  'fraction part = true 0.01..0.99

    End If


    'final hex-str array position is depending on the freq value
    'insert the Hex str into array with inverted order from right to left = the final string

    Dim dd As Double = 0
    Dim bitpos As Integer = 1           'default Hex-array position
    Dim le As Integer = Len(s1)
    Dim v1000, v100, vdec As Integer

    If le = 3 Then 'value is multiplied by 100
        ' below 1000 and over 99.99
        '00 00 30 00 00  = 300
        '00 10 30 00 00  = 301
        '00 10 31 00 00  = 311
        v100 = Val(Mid(s1, 1, 2))
        vdec = Val(Mid(s1, 3, 1))

    ElseIf le = 4 Then
        'Freq Integer over 999.99 and below 10.000
        '9900 - value * 1000
        v1000 = Val(Mid(s1, 1, 1))
        v100 = Val(Mid(s1, 2, 2))
        vdec = Val(Mid(s1, 4, 1))

        'freq Integer over 9999.99 and below 100.000,00
    ElseIf le = 5 Then
        '12345
        v1000 = Val(Mid(s1, 1, 2))
        v100 = Val(Mid(s1, 3, 2))
        vdec = Val(Mid(s1, 5, 1))

    End If

    If le = 3 Then    'value is multiplied by 10
        '310
        '    hex array position                     0  1  2   3   4 |  2     1      0
        'we use only the first 3 byte              |10 15 31| 00 00 = 310 + 1.50 + 0.01 (10/10)
        'first 2
        bitpos = 1
        shex4(3 - bitpos) = v100.ToString()
        bitpos = bitpos + 1
        'bitpos start with 3 = byte 1
    ElseIf le = 4 Then  'value is multiplied by 1000
        shex4(3 - bitpos) = "0" & v1000.ToString()  'is less then 10, below 10.000
        bitpos = bitpos + 1
        'bitpos start with 2 = byte 2
    ElseIf le = 5 Then 'value is multiplied by 10000
        shex4(3 - bitpos) = v1000.ToString()  'is > 9999.99 and less then 100.000
        bitpos = bitpos + 1
    End If

    '123
    If le = 3 Then
        ' + vdec
        If vdec * 10 > 0 Then _
           shex4(3 - bitpos) = vdec * 10.ToString()

        If frac Then
            InsertDec4Byte(freqfrac)
        End If

    End If

    '1234, 12345
    If (le = 4 Or le = 5) Then
        ' + v100 + vdec

        If v100 < 10 Then
            sStr = "0" & v100.ToString
        Else
            sStr = v100.ToString
        End If

        If v100 > 0 Then _
           shex4(3 - bitpos) = sStr.ToString()
        'else we do not consider, Hex value = already "00"
        bitpos = bitpos + 1

        If vdec * 10 > 0 Then _
            shex4(3 - bitpos) = vdec * 10.ToString()

        If frac Then
            InsertDec4Byte(freqfrac)
        End If
    End If


    If bcdinverted Then
        sStr = ""
        For i As Integer = 3 To 0 Step -1
            sStr = sStr & shex4(i).ToString() & " "
        Next

    Else

        sStr = ""
        For i As Integer = 0 To 3
            sStr = sStr & shex4(i).ToString() & " "
        Next

    End If


    Return sStr

End Function

Private Sub InsertDec(ByVal frac)
    Dim dd As Double
    Dim freqfrac As String = frac
    If frac Then
        Dim f1, f2, h2 As Double
        'even 50    even
        dd = Val(freqfrac)
        f1 = Val(shex5(1))             '10
        f2 = Val(Mid(freqfrac, 1, 2)) '50
        If (dd Mod 10 = 0) Then
            '0.50
            f2 = f2 / 10                  '5
            h2 = f1 + f2
            If h2 < 10 Then
                shex5(1) = "0" & h2.ToString()       '15
            Else
                shex5(1) = h2.ToString()       '15
            End If
        Else
            '51 - Odd
            f2 = Val(Mid(freqfrac, 1, 1)) '5
            h2 = f1 + f2                  ' 10 + 5

            If h2 < 10 Then
                shex5(1) = "0" & h2.ToString()       '15
            Else
                shex5(1) = h2.ToString()       '15
            End If

            f2 = Val(Mid(freqfrac, 2, 1)) '1
            f2 = f2 * 10
            shex5(0) = f2                  '10 = 0.01

        End If
    End If
End Sub

Private Function SendHexStr(ByVal hs) As String

    Dim sStr As String = ""
    Dim s1 As String = ""
    Dim freq As String = ""
    Dim freqfrac As String = ""
    Dim ppos As Integer = 0
    Dim frac As Boolean = False

    'fill the array with Hex '00'
    For i As Integer = 0 To 4
        shex5(i) = "00"
    Next

    freq = hs
    freq = Replace(freq, ",", ".")
    s1 = freq

    'copy the fraction part if any - 500.01 - 501.50
    ppos = InStr(1, freq, ".", CompareMethod.Text)
    If ppos > 0 Then
        'copy only the integer part as frequency
        s1 = Mid(s1, 1, ppos - 1)
        'the fraction part
        freqfrac = Mid(freq, ppos + 1, Len(freq) - ppos)

        'correct input error
        If Len(freqfrac) = 1 Then freqfrac = freqfrac & "0"
        If Len(freqfrac) = 0 Then freqfrac = freqfrac & "00"

        frac = Not frac  'fraction part = true 0.01..0.99

    End If


    'final hex-str array position is depending on the freq value
    'insert the Hex str into array with inverted order from right to left = the final string

    Dim dd As Double = 0
    Dim bitpos As Integer = 1           'default Hex-array position
    Dim le As Integer = Len(s1)
    Dim v100000, v1000, v100, vdec As Integer

    If le = 3 Then 'value is multiplied by 100
        ' below 1000 and over 99.99
        '00 00 30 00 00  = 300
        '00 10 30 00 00  = 301
        '00 10 31 00 00  = 311
        v100 = Val(Mid(s1, 1, 2))
        vdec = Val(Mid(s1, 3, 1))

    ElseIf le = 4 Then
        'Freq Integer over 999.99 and below 10.000
        '9900 - value * 1000
        v1000 = Val(Mid(s1, 1, 1))
        v100 = Val(Mid(s1, 2, 2))
        vdec = Val(Mid(s1, 4, 1))

        'freq Integer over 9999.99 and below 100.000,00
    ElseIf le = 5 Then
        '12345
        v1000 = Val(Mid(s1, 1, 2))
        v100 = Val(Mid(s1, 3, 2))
        vdec = Val(Mid(s1, 5, 1))

        'freq Integer upto > 999.999,99
    ElseIf le = 6 Then
        '123456
        v100000 = Val(Mid(s1, 1, 1))
        v1000 = Val(Mid(s1, 2, 2))
        v100 = Val(Mid(s1, 4, 2))
        vdec = Val(Mid(s1, 6, 1))

        'freq Integer upto > 1.999.999,99 stop x ICOM R 8500
    ElseIf le = 7 Then
        '1234567
        v100000 = Val(Mid(s1, 1, 2))
        v1000 = Val(Mid(s1, 3, 2))
        v100 = Val(Mid(s1, 5, 2))
        vdec = Val(Mid(s1, 7, 1))
    End If

    If le = 3 Then    'value is multiplied by 10
        '310
        '    hex array position                     0  1  2   3   4 |  2     1      0
        'we use only the first 3 byte              |10 15 31| 00 00 = 310 + 1.50 + 0.01 (10/10)
        bitpos = 2
        shex5(4 - bitpos) = v100.ToString()
        bitpos = bitpos + 1
        'bitpos start with 3 = byte 1
    ElseIf le = 4 Then  'value is multiplied by 1000
        shex5(4 - bitpos) = "0" & v1000.ToString()  'is less then 10, below 10.000
        bitpos = bitpos + 1
        'bitpos start with 2 = byte 2
    ElseIf le = 5 Then 'value is multiplied by 10000
        shex5(4 - bitpos) = v1000.ToString()  'is > 9999.99 and less then 100.000
        bitpos = bitpos + 1
        'bitpos start with 2 = byte 2
    ElseIf le = 6 Then  'upto 999.999,99
        shex5(4) = "0" & v100000.ToString()
        'bitpos start with 1 = byte 3
    ElseIf le = 7 Then  'upto 1.999.999,99 ICOM R8500 limit
        '90 78 56 34 12  = 1,234,567,89
        shex5(4) = v100000.ToString()
        'bitpos start with 1 = byte 3
    End If


    '123
    If le = 3 Then
        ' + vdec
        If vdec * 10 > 0 Then _
           shex5(4 - bitpos) = vdec * 10.ToString()

        If frac Then
            InsertDec(freqfrac)
        End If

    End If

    '1234, 12345
    If (le = 4 Or le = 5) Then
        ' + v100 + vdec

        If v100 < 10 Then
            sStr = "0" & v100.ToString
        Else
            sStr = v100.ToString
        End If

        If v100 > 0 Then _
           shex5(4 - bitpos) = sStr.ToString()
        'else we do not consider, Hex value = already "00"
        bitpos = bitpos + 1

        If vdec * 10 > 0 Then _
            shex5(4 - bitpos) = vdec * 10.ToString()

        If frac Then
            InsertDec(freqfrac)
        End If
    End If


    '123456 + 1234567
    If le = 6 Or le = 7 Then
        ' + v1000 + v100 + vdec
        If v1000 > 9 Then
            shex5(4 - bitpos) = v1000.ToString()
            bitpos = bitpos + 1
        Else
            shex5(4 - bitpos) = "0" & v1000.ToString()
            bitpos = bitpos + 1
        End If

        If v100 < 10 Then
            sStr = "0" & v100.ToString
        Else
            sStr = v100.ToString
        End If

        If v100 > 0 Then _
           shex5(4 - bitpos) = sStr.ToString()
        'else we do not consider, Hex value = already "00"
        bitpos = bitpos + 1

        If vdec * 10 > 0 Then _
            shex5(4 - bitpos) = vdec * 10.ToString()

        If frac Then
            InsertDec(freqfrac)
        End If
    End If

    sStr = ""
    For i As Integer = 0 To 4
        sStr = sStr & shex5(i).ToString() & " "
    Next

    Return sStr

End Function

'--------------------------------------------- '---------------------------------------------

Окончательная процедура с использованием функции ToBcd5, предложенная Джими

Private Sub HexFreq5Byte(ByVal sfreq)

  'Using the ToBcd5 Function proposed by Jimi
  '
  'This procedure is only returning the correct Number considering the Fraction part
  'For a use where always 5 bytes are requested this procedure must be extended
  '    and the returned bytes must be inserted into a 5-Byte BCD.
  '    A Radio connected to a Com-Port is always requesting a FIX BCD-Byte number.
  '    We must transmit and receive Bytes together with other Parameters.
  '
  '    I will have to do that extension

  Dim pPos As Integer = 0
  Dim frac As Boolean = False
  Dim value As Double = 0.0
  Dim ssfreq As String = Replace(sfreq, ",", ".")
  Dim sStr As String = ""
  Dim hfreq As String = ""
  Dim sp As String = " "    '1 space dividing bytes

  'eventual correction
  ssfreq = Replace(ssfreq, ",", ".")

  Try

  'Adjust the Fraction part
  'When Fraction (frac) is True the end result must be divided by 100
  pPos = InStr(1, ssfreq, ".", CompareMethod.Text)
  If pPos > 0 Then

      'the fraction part
      sStr = Mid(ssfreq, pPos + 1, Len(ssfreq) - pPos)
      'correct input error
      If Len(sStr) = 1 Then ssfreq = ssfreq & "0"
      If Len(sStr) = 0 Then ssfreq = ssfreq & "00"

      frac = Not frac  'fraction part = true 0.01..0.99

  End If

  hfreq = ""
  sStr = ""
  ssfreq = Replace(sfreq, ".", "")
  ssfreq = Replace(sfreq, ",", "")

  'get the BCD Bytes
  'the function is returning the nr of bytes used as "bcd5bytes"
  Dim ret As Byte() = New Byte(bcd5bytes) {}
  ret = ToBcd5(Val(ssfreq))

  sStr = ""
  'Adjust the Byte with "0" in front or behind
  For i As Integer = 0 To bcd5bytes - 1

      sStr = Hex(ret(i))
      If Len(sStr) = 1 Then
          If sStr = "0" Then
              sStr = sStr + "0"
          Else
              sStr = "0" & sStr
          End If
       End If

       'insert a space between the bytes if you need it
       hfreq = hfreq + sStr & sp  'sp = 1 space

   Next

   hfreq = Trim(hfreq)

   'cut the spaces between the bytes x adding values
   hfreq = Replace(hfreq, " ", "")

   'Convert to Number
   '2 Byte = 4 Digit. Read first the last byte pos 3 + 4
   'counter is a double to get out of the 'While loop'.

   Dim counter As Double = bcd5bytes * 2 - 1
   Dim s1 As String = hfreq
   sStr = ""

   While counter > 0    'read BCD/Byte from right to left

       sStr = sStr & Mid$(s1, counter, 2)
       counter = counter - 2
       If counter = 0 Then counter = 1

   End While

   'adjust the return value and the fraction part if any
   value = Val(sStr)
   If value > 0.0 Then

       If frac Then value = value / 100

       'The end result
       sStr = value.ToString("f2")

   End If

 Catch ex As Exception
     MsgBox("Value exceeding Frequency maximum.")
 End Try

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