asked on

byte conversion question

I need to write a function to convert a one or two digit number into a single byte starting with 1. Can someone please explain what I need to do?

Im doing serial port communication with an external device. Basically I want to send the address command "12" to the device, or in byte form starting with a 1 it would be 10001100. In the notes for the protocol it says the address should be "1 byte, 0-127 must add 128 to indicate as address".

Just wondering how I should calculate the bytes to send?

rockiroads

Would CByte help?
There is also CType

craigdev

ASKER

not sure?

craigdev

ASKER

This is what I have so far, just for testing.
When I enter "12" in the text box it displays 00110000
But I need it to display 10001100

'code:
Public Class Form1
Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

Public Sub New()
MyBase.New()

'This call is required by the Windows Form Designer.
InitializeComponent()

'Add any initialization after the InitializeComponent() call

End Sub

'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub

'Required by the Windows Form Designer
Private components As System.ComponentModel.IContainer

'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
Friend WithEvents lblOutput As System.Windows.Forms.Label
Friend WithEvents btnConvert As System.Windows.Forms.Button
Friend WithEvents tbInput As System.Windows.Forms.TextBox
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.lblOutput = New System.Windows.Forms.Label
Me.btnConvert = New System.Windows.Forms.Button
Me.tbInput = New System.Windows.Forms.TextBox
Me.SuspendLayout()
'
'lblOutput
'
Me.lblOutput.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
Me.lblOutput.Location = New System.Drawing.Point(240, 40)
Me.lblOutput.Name = "lblOutput"
Me.lblOutput.TabIndex = 0
Me.lblOutput.TextAlign = System.Drawing.ContentAlignment.MiddleLeft
'
'btnConvert
'
Me.btnConvert.Location = New System.Drawing.Point(152, 40)
Me.btnConvert.Name = "btnConvert"
Me.btnConvert.TabIndex = 1
Me.btnConvert.Text = "Convert"
'
'tbInput
'
Me.tbInput.Location = New System.Drawing.Point(48, 40)
Me.tbInput.Name = "tbInput"
Me.tbInput.TabIndex = 2
Me.tbInput.Text = "12"
'
'Form1
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(392, 118)
Me.Controls.Add(Me.tbInput)
Me.Controls.Add(Me.btnConvert)
Me.Controls.Add(Me.lblOutput)
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)

End Sub

#End Region

Private Sub btnConvert_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConvert.Click
Dim bytes() As Byte = {Me.tbInput.Text}
Dim ba As New BitArray(bytes)
For Each bit As Boolean In ba
Select Case bit
Case True
Me.lblOutput.Text += "1"
Case False
Me.lblOutput.Text += "0"
End Select
Next
End Sub
End Class

SOLUTION

vadim63

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rockiroads

dont know if u can cheat and use VAL to remove leading zeros
e,g.

VAL(CSTR(00110000))

or

CDBL(00110000)

craigdev

ASKER

vadim63 thats awesome, thanks

So it looks like adding 128 simply shifts the bits to the right and places a new 1 infront :)

Is there a way to convert it back at the same time? so taking 12 --> 00110000 --> 10011000 --> ?

ASKER CERTIFIED SOLUTION

vadim63

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vadim63

Actually, it's good for numbers between 0 and 127

SOLUTION