Sunday, 13 January 2013

Arduino Relay Outlet

I recently received my Arduino Uno and went straight to my automation project.
I bought my Arduino from Hobbytronics South Africa, 3 days to deliver to my holiday destination in rural area.

The plan is to control outlets in my apartment using my Arduino and pc, this would later on evolve to a wireless system using Ethernet shield.

This is what I used in short:

  • Arduino UNO
  • SPDT Relay 220V compatible (' JZC11F'
  • Normal Relay outlet box
  • and the usual components. 

I built my own relay shield since I didn't have one, but you can easily buy a small relay shield for very cheap on Ebay. Due to the size of my breadboard I had to keep the "relay shield" on the outside of the enclosure, not very practical but was fine for testing the project.

This is how my little experiment turned out:

As you can see this takes quite alot of space and I will soon replace my DIY "relay shield" with a smaller alternative from ebay. This would fit nicely into my  outlet box.

I recently purchased my ethernet shield, relay shield and a lcd module to show the main unit's status at all time.
The final plan is to house and arduino in each room with it's relay outlet boxes connected and the main unit near my router. The arduino's would communicate to main unit via RF and the main unit to my web server.
Coding and schematics is available on request!

Wednesday, 17 August 2011

Automate Excel Copy

Simple Guide how to automate copying cells or more from excel to other workbooks or another sheet using
Here is the code I used, I had the following controls on my form:
2 Radio Buttons
3 Labels
2 Text Boxes
1 Button

Just change the names of the controls in the coding to the names you used!

'we need to import the Excel interop to reference to excel
Imports Excel = Microsoft.Office.Interop.Excel
Imports System.IO
Public Class Form1

Private Sub btnOk_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOk.Click
End Sub
Dim XLapp As Excel.Application
Dim XLwrkb As Excel.Workbook
Dim XLsheet As Excel.Worksheet
Dim path As String
Public Sub Copy()

Path = OpenFileDialog1.FileName ' Assigns the path of file chosen by user to the string path

'Open a new excel application
XLapp = New Excel.Application
XLapp.Visible = False 'we don't want the user to know excel is being opened!

'Open the workbok in our excel app
XLwrkb = XLapp.Workbooks.Open(path, [ReadOnly]:=False)
XLsheet = XLwrkb.ActiveSheet ' Reads the first sheet of the workbook

If RadioButton2.Checked = True Then



ElseIf RadioButton1.Checked = True Then
'The program will check if the user want to paste the range into a new workbook. It then ask the user to select
' the new workbook it want to paste the cellc in.
path = OpenFileDialog1.FileName

'Open a new excel application
XLapp = New Excel.Application
XLapp.Visible = False 'we don't want the user to know excel is being opened!

'Open the workbok in our excel app
XLwrkb = XLapp.Workbooks.Open(path, [ReadOnly]:=False)
XLsheet = XLwrkb.ActiveSheet ' Reads the first sheet of the workbook


End If

End Sub

Tuesday, 2 August 2011

Data Validation Class

After having several problems regarding null I have decided to do the right thing and create a Data Validation Class. What this class does is check each data before I use it for null.

If this is the first time you hear about null there is some basic things to learn:

  • A null value is a value that doesn't refer to any object. It's the default value of reference-type variables (e.g., class, interface, and delegate).
  • The null keyword is a literal that represents a null reference with the .NET environment. 
  • There is a difference between null and '0' the value.
  • Null is nothing where '0' is assigned as a value. 
To start out create a new class in your project, in my case my class is called DataVal.vb
Working with a database I prefered to assign '0' to all my null values if they are numeric.
I later on run a query that searches my tables for the '0' records and then remove them.
"DELETE * From Table WHERE Field = 0 "
This however depends on the function of your tables and program.

This is the code used in my class:

Public Class DataVal
    Public Function Validate(ByVal input)
        If input = Nothing Then
            input = "0"
            Return input
        End If
        Return input
    End Function
End Class

DV = DataValidate class....
Use this function to set the value of your object, eg. txtName.Text = (DV.Validate(txtName.Text))
It works for integers, doubles basically all data types.

Please comment your solution to validate data.

Saturday, 30 July 2011

Hello World - Your First Android App

Recently I was looking into the option of porting my application to android. So here is a tutorial on how to write your very first android applications.

What you need:

Java knowledge
Java SDK v6.0 or above
MotoDev (Based on Eclispe) -
Android SDK (latest) -

I also recommend reading about how the android system works, the manifest file, gui file(main) , etc.

To start out instal JDK, Android SDK and update, MotoDev studio.
Set up a AVD.  
In motoDev now create a new Project and give it a appropiate name.

You will notice that the an Android application is based on the Activity class, and always reference to

Change the code in activity to corospond with the following:
import android.widget.TextView;

public void onCreate(Bundle savedInstanceState) 
         TextView tv = new TextView(this);
       tv.setText("Hello, Android");
The enlarged code is the code changed or added.
The onCreate() method is used to start your activity.
In android objects is referred to views. 
TextView will be the equvalint to an Label in .net programming or swing.
Now Run the application.

Thursday, 14 July 2011

Dynamic Create Controls on Runtime

Here is my quick guide on how to generate ImageHolder Buttons on runtime. This is perfect and works nice with inventory systems or payroll applications.(ID picture of employee)

First of all create a new project, drag a panel onto your form.
Double click on your form to open up the Form_Load() method and Return to design view.

Wednesday, 13 July 2011

Paste Excel Data Into DataGrid in

How to paste excel clipboard data in datagrid:

Private Sub PasteClipboard()

        Dim s As String

            s = Clipboard.GetText()
            Dim i, ii As Integer

            Dim tArr() As String = s.Split(ControlChars.NewLine)
            Dim arT() As String
            Dim cc, iRow, iCol As Integer

            iRow = DataGridView1.SelectedCells(0).RowIndex
            iCol = DataGridView1.SelectedCells(0).ColumnIndex
            For i = 0 To tArr.Length - 1
                If tArr(i) <> "" Then
                    arT = tArr(i).Split(vbTab)
                    cc = iCol
                    For ii = 0 To arT.Length - 1
                       If cc > DataGridView1.ColumnCount - 1 Then Exit For
                       If iRow > DataGridView1.Rows.Count - 1 Then Exit Sub
                        With DataGridView1.Item(cc, iRow)
                            .Value = arT(ii).TrimStart

                        End With
                        cc = cc + 1
                    iRow = iRow + 1
                End If


        Catch ex As Exception
            MsgBox("Please redo Copy and Click on cell")
        End Try
    End Sub

Just change the value of DataGridView1 to the objectname of your DataGrid. This can paste rows and columns.