Converting a 16 bit twos complements value to decimal value : algorithm and implementation

Converting a 16 bits twos complement value to a decimal value equivalent. In this tutorial a simple algorithm and implementation are shared.

Main sub

Sub Main
    
 Dim result As Short = 0
 Dim value = 50
 result = GetDecimalValue(value)
 Console.WriteLine("Decimal value of " & value & " is "& result)
End Sub

  

Get the sign sub

Function GetSign16Bit( value)
'This function returns -1 if the 16 bits value is negative and 1 if it is zero or positive
   Dim sign = 0
   value = value/ 256    'Get the left most byte
   value = value / 16    'Get the leftmost 4-bits
   value = value / 4     'Get the leftmost 2-bits
   value = value / 2     'Get the  leftmost 1-bit
    If  value  >=1 Then
         sign = -1
    Else
          sign= 1
    End If
   Return sign
End Function

  

Converting to decimal value sub

Function GetDecimalValue(value)
'This function takes the twos complement of a 16 bits value and  return the equivalent decimal value
' We know that, 2^16 =65536
    Dim ValueOneComplement, Result 
 If  GetSign16Bit(value) = 1 Then  ' Positive number
         Result = value
    Else                              'Negative number
            ValueOneComplement = Not  value  ' get the one's complement of the value
            Result =  (65536  + ValueOneComplement ) +1 
            Result = - Result  'Make the value negative by prefixing it with minus
    End If
 Return Result
End Function

  

This is just a trick, hope it paved your way out. 

LINQPAD - How to Insert data into MySQL using VB

This snippet connect to MySQL in LINQPAD using Visual Basic. Make sure you download the MySql.Data.DLL, unblock the zip file then extract it and add that reference in LINQPAD by pressing F4 as shown in the video here

Main sub

Sub Main
 Dim query As String
 Dim stid As Integer
 Dim name, programme As String
 stid = 13
 name = "Nemo"
 programme = "Search of Nemo"
 query ="insert into Student(Stid,Name,Programme) values (" & stid & ",'" & name & "','" &  programme & "')"
 insertInDB (query)
End Sub

  

Insertion sub

Sub InsertInDB (query As String)

      'Declaring variables
     Dim conn As New MySqlConnection()
  Dim sqlCmd As MySqlCommand 
  'Connection string to MySQL
        conn.ConnectionString = "Persist Security Info=False;database=springboot;server=localhost;Connect Timeout=30;user id=springboot; pwd=springboot"
        Try
      'Connecting and executing the query
            conn.Open()
   sqlCmd = New MySqlCommand( query, conn)
   sqlCmd.ExecuteNonQuery()
   'Closing the query
   conn.Close()
        Catch myerror As MySqlException
  'Throwing exceptions
            Console.WriteLine("Error connecting to database!")
            Exit Sub
        End Try
        Console.WriteLine("connected to database!")
End Sub
  

This is just a trick, hope it paved your way out.