Communication is vital in programming. Our software must communicate not only with person but also with hardware machine or other software. This slides introduce few techniques that can be used in communicating among various and third party software and hardware.

1. Communication
Skills
in Programming
By :
Suhailan bin Dato’ Hj. Safei
Faculty of Informatics
suhailan@unisza.edu.my
suhailan@unisza.edu.my

2. Communications
– The message (data and information) is communicated via the signal
– The transmission medium “carries” the signal
Transmission
medium
Sender Signal Receiver
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3. suhailan@unisza.edu.my

4. Communications in programming
Sender Signal Receiver
Keyboard, Mouse, Notepad, Word, Pdf,
Pendrive, Harddisk, OS, Browser
Hardware Send keyboard input to notepad Software
Software Send pdf to printer Hardware
Software Export MsWord to Pdf Software
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5. Types of Programming Communication
• Dynamic link library (DLL)
• Component Object Model (COM)
• ActiveX
• Windows Shell
• Text File
• Database
• Shared Memory
• Serial command – comm port, AT command
• Communication Protocol - TCP/IP, UDP, FTP, HTTP, POP3, etc.
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6. Dynamic Link Library
• A dynamic-link library (DLL) is a module that contains functions and data
that can be used by another module (application or DLL).
• A DLL can define two kinds of functions: exported and internal. The
exported functions are intended to be called by other modules, as well as
from within the DLL where they are defined. Internal functions are
typically intended to be called only from within the DLL where they are
defined. Although a DLL can export data, its data is generally used only by
its functions. However, there is nothing to prevent another module from
reading or writing that address.
• DLLs provide a way to modularize applications so that their functionality
can be updated and reused more easily. DLLs also help reduce memory
overhead when several applications use the same functionality at the
same time, because although each application receives its own copy of the
DLL data, the applications share the DLL code.
Source: http://msdn.microsoft.com/en-us/library/windows/desktop/ms682589%28v=vs.85%29.aspx6
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7. Create DLL
Compile and save this file as “Example.dll”.
Source : http://en.wikipedia.org/wiki/DLL
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8. Call DLL
Source : http://en.wikipedia.org/wiki/DLL
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9. DLL for OCR
• ASPIRE
– Download “AspriseOCR.dll”
(http://asprise.com/product/ocr/download.php?lang=vb)
To call the DLL using VB…
Private Declare Function OCR Lib "AspriseOCR.dll" (ByVal file
As String, ByVal imageType As Long) As String
Private Sub Command3_Click()
Dim txt As String
txt = OCR ("C:pic1.bmp", -1)
MsgBox "The text are:" & txt
End Sub
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10. DLL Communication (PCI Card)
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11. COM
• Microsoft COM (Component Object Model) technology in the Microsoft
Windows-family of Operating Systems enables software components to
communicate. COM is used by developers to create re-usable software
components, link components together to build applications, and take
advantage of Windows services. COM objects can be created with a variety
of programming languages. The family of COM technologies includes
COM+, Distributed COM (DCOM) and ActiveX® Controls.
• Microsoft provides COM interfaces for many Windows application
programming interfaces such as Direct Show, Media Foundation,
Packaging API, Windows Animation Manager, Windows Portable Devices,
and Microsoft Active Directory (AD).
• COM is used in applications such as the Microsoft Office Family of
products. For example COM OLE technology allows Word documents to
dynamically link to data in Excel spreadsheets and COM Automation
allows users to build scripts in their applications to perform repetitive
tasks or control one application from another. 11
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12. COM
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13. Using PHP to call COM
<?php
$excel_app = new COM("Excel.application") or die ("Did not connect");
$excel_app->Application->Visible = 1; //Make Excel visible.
$Workbook = $excel_app->Workbooks->Open("D:wampwwwtesttest.xlsx") or
Die(“Failed");
$Worksheet = $Workbook->Worksheets("Sheet1");
$Worksheet->activate;
echo $Worksheet->Range("A1")."-".$Worksheet->Range("B1")."<br>";
echo $Worksheet->Range("A2")."-".$Worksheet->Range("B2")."<br>";
$Workbook->Close;
unset($Worksheet);
unset($Workbook);
$excel_app->Workbooks->Close();
$excel_app->Quit();
unset($excel_app);
?>
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14. ActiveX
• ActiveX is a Microsoft-created technology that enables different software
applications to share information and functionality. ActiveX only works on
the Windows operating system. ActiveX and COM is same, as it was build
under COM platform. The different is that ActiveX provides easier control
graphical interface(running software component in your application).
• ActiveX controls are mostly talked about in reference to Internet Explorer.
You don't have to launch the Windows Media Player application
separately to run a video clip on your browser.
• Another common ActiveX control plays Flash files (.swf). Internet
Explorer can't play Flash files by itself. That's something only the Adobe
Flash Player can do. So Internet Explorer gives you the option of
downloading and installing the Flash ActiveX Control. The Flash ActiveX
Control automatically detects when a site contains Flash files. It then
accesses the Flash player functionality at the operating system level and
plays the files directly in the browser.
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15. ActiveX Communication
Windows
Media Player
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16. ActiveX Communication
FITNewsTV application
- VideoLAN player activeX
running imported using
Borland C++ Builder
TCppWebBroswer – an VLC Media Player
activeX of Internet Explorer
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17. Serial Command
• Connection to other hardware (computer, modem, printer,
microcontroller, sensors) can be done using serial cable such as RS232
(connection up to 15meter).
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18. Serial Communication (Microcontroller)
RS232 cable
microcontroller
Temperature
sensors for gas
turbine
Display
temperature
value here
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19. Serial Communication (UHF/Satellite)
RS232 cable
Send message from
ship to ship using
very small aperture satellite
terminal (VSAT)
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20. Serial Communication (AT Command)
Water level sensor AT Command
to Modem
(serial com)
Landline Display reservoir level
microcontroller Telephone
(telekom)
RS232
Connected to
microcontroller at
site using modem
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21. Windows Shell
• The Windows UI provides users with access to a wide variety of objects
necessary for running applications and managing the operating system.
The most numerous and familiar of these objects are the folders and files
that reside on computer disk drives.
• There are also a number of virtual objects that allow the user to perform
tasks such as sending files to remote printers or accessing the Recycle Bin.
The Shell organizes these objects into a hierarchical namespace and
provides users and applications with a consistent and efficient way to
access and manage objects.
• Eg.
– ShellExecute – to execute a window executable file provided with their
parameters
– FindWindow – to get the handle of running software’s window/form
– SetParent– set the window main handle to be controlled from your
own application
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22. Windows Shell
Use windows shell API-
FindWindow and SetParent to
put YM application in UniSZA
Messenger application
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23. Text file communication
Dump the value
into a network
shared text file
Our software read value in
Sensor software read the windLog.txt file via
wind log via RS232 network sharing
WindSensor –
speed/direction
Display the wind
direction and
speed value in a
web via graphic
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24. Database Communication (SQL)
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25. TCP/IP Communication
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26. Enhance your software
communication skills with
FACEBOOK…
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