Module scaleMoudule

    Declare Function GetTickCount Lib "kernel32" Alias "GetTickCount" () As Integer

    Public rxMessage As String
    Public pasingdata As String
    Public Const RetryCnt As Integer = 3
    Dim WaitGo As String

    Public Function MeasureScale(timeout As Long) As String
        Dim StartTick, CurrTick As Long
        Dim tmpVal As String
        Dim tmpRxMessage As String = ""
        Dim CmdRet As String = ""
        Dim MeasureVal As Double

        For cnt = 1 To RetryCnt

            weightForm.cmdSerialPort.DiscardInBuffer()
            weightForm.cmdSerialPort.DiscardOutBuffer()

            rxMessage = ""
            StartTick = GetTickCount
            weightForm.cmdSerialPort.Write(Chr(&H5))
            While (CurrTick - StartTick <= timeout)
                CurrTick = GetTickCount

                CmdRet = ReceiveByteSerial()

                Select Case CmdRet
                    Case "START"
                        StartTick = GetTickCount
                        rxMessage = ""
                        weightForm.cmdSerialPort.Write(Chr(&H11))

                    Case "COMPLETE"
                        CmdRet = "FAIL"
                        If Len(rxMessage) = 15 Then
                            WaitGo = Mid(rxMessage, 3, 1)
                            tmpVal = Mid(rxMessage, 5, 6)
                            For i = 1 To Len(tmpVal)
                                If Mid(tmpVal, 1, 1) = Chr(&H20) Then
                                    tmpVal = Mid(tmpVal, 2, Len(tmpVal) - 1)
                                End If
                            Next
                            Return WaitGo & tmpVal.ToString
                        ElseIf Len(rxMessage) = 16 Then
                            WaitGo = Mid(rxMessage, 3, 1)
                            tmpVal = Mid(rxMessage, 5, 7)
                            For i = 1 To Len(tmpVal)
                                If Mid(tmpVal, 1, 1) = Chr(&H20) Then
                                    tmpVal = Mid(tmpVal, 2, Len(tmpVal) - 1)
                                End If
                            Next
                            MeasureVal = Val(tmpVal) / 10
                            Return WaitGo & MeasureVal.ToString
                        Else
                            Exit While
                        End If
                End Select
                CmdRet = "TIMEOUT"
            End While
        Next

        Return CmdRet
    End Function
    Public Function ReceiveByteSerial() As String
        Dim n As Integer = weightForm.cmdSerialPort.BytesToRead
        Dim comBuffer As Byte()

        Try

            comBuffer = New Byte(n - 1) {}
            weightForm.cmdSerialPort.Read(comBuffer, 0, n)

            For cnt = 0 To comBuffer.Length - 1
                rxMessage = rxMessage & Chr(comBuffer(cnt))
            Next

            If Mid(rxMessage, 1, 1) = ChrW(6) Then
                Return "START"
            ElseIf Len(rxMessage) > 14 Then
                If Mid(rxMessage, InStr(rxMessage, ChrW(1)), 2) = ChrW(1) & ChrW(2) Then
                    rxMessage = Mid(rxMessage, InStr(rxMessage, ChrW(1)), (Len(rxMessage)))

                    If Mid(rxMessage, InStr(rxMessage, ChrW(3)), 2) = ChrW(3) & ChrW(4) Then
                        rxMessage = Mid(rxMessage, 1, InStr(rxMessage, ChrW(4)))

                        Return "COMPLETE"
                    End If
                End If
            End If

            Return "FAIL"
        Catch ex As Exception
            MsgBox("DataReceived," & ex.Message)
            Return False
        End Try
    End Function
End Module