Interfacing Embedded System with Computer Software Using VB.net

forestevanescentΗλεκτρονική - Συσκευές

2 Νοε 2013 (πριν από 3 χρόνια και 9 μήνες)

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Interfacing Embedded System with
Computer Software Using VB.net

Presented by :
-

Sulaiman

Salim

AL
Habsi



Why VB.NET ????????


New implementation of classic VB on .NET
framework .


Object Oriented Programming Language .


Very close to human language .


Not case sensitive .


Easier Graphical User Interface (GUI).


Data types and Declaration


int



Integer


string


String


double


Double


char


Char


bool



Boolean


Dim [variable name] As [data type].


Do not use semicolon !!!!! .


Function and Loops


While loop



Do While
(condition)


-

statement


Loop



Do Until
(condition)


-
statement


loop



Functions and loops


For loop



For

[variable name]=
init

To

[max]


-
statement


Next


For each
(
google
)

Function



Public Sub
functionName
(
ByRef

f
As Integer
)




End Sub

Function



Public Function
R_function
(
ByVal

h
As String
)
As String






Return
"String"



End Function

DLL


Use ready code


Intermediate language for all .NET frame work


Add to the project


Import to
the class


URL request


URL request are used request a html
document from a web server .


If you are behind a web proxy you’ll need to
but proxy setting .


How to make a URL
requist


Imports
System.Net


Imports

System.IO


New

webClient



New

stream =
webClient
.OpenRead


New

StreamReader
(stream)



While Not
isr.EndOfStream


str

+=
isr.ReadLine
()



End While


Proxy setting



New
NetworkCredential
(“username", “pass",
“domain")


New
WebProxy
(“
proxyserver
", port)



proxy.Credentials

=
cr



Dim
stoper

As Boolean = True



proxy.BypassProxyOnLocal

= True


T
hread


Thread: making the program doing more than
one task at the same time .


Some object already have threads


VB does not allow accessing thread form an
other thread . We need an other solution


Timer is on of the solution of the problem


If your thread task is done then you cant start
the thread again



How to create a thread


Imports Threading
‘ outside the class


Dim
myThread

A
s

Thread


myThread

=
new

Thead
(
addressOf

myInfitTask
)


myThread.start
()

Example


Make a http request to Google web site .


1
-

display full html in a text field


2
-

display the head tag only .


3
-

make a other button to request SQU web
site in the same time .


4
-

modify the code in 3 so you use less
redundancy .


Serial communication in ES


Atmel
AVR microcontrollers


Serial communication


Send bits in serial


Less wiring and asynchronous and synchronous


Baud rate is number of bits per second
=(F_CPU/16*baud)
-
1



voltage level in microcontroller is different
from computer (use Max232).




RCX: Data receive complete

UDRE:Ready for transition

U2X : double the transition baud rate

RXEN: Enable Receive Data

TXEN: Enable Transmit Data

UCPOL: Using the USART as synchronous or a synchronous

UCSZ0/1:select the Size Of data(5,6,7,8)bits

USBS: number of stop bit

UPM0/1:parity (none, odd , even)

UMSEL /URSEL : put to Zero.

UBRR : set baud rate

UDR : transmit receive data

Serial port object


Imports
system.io.ports


Define connection configurations


Using with


Read the buffer using timer


Change the ports form the system


Some GSM modems use virtual serial port


Using AT command to control GSM Modem


You can put some of the configuration during the
creation of the object.

Create and configure serial port


Imports

System.IO.Ports


Dim
serialport

As new
SerialPort


With

serialport




.
PortName

=
“COM1
"



.
BaudRate

= 9600



.
StopBits

=
StopBits.One



.
DataBits

= 8



.Parity =
Parity.None



.Open
()


End With



example


Write a program in VB.net that receive a
message (number from a web server and
display it in a BCD 7 segments in the testing
board) use the URL
(http://172.22.13.12/embedded)

If you are enemy of Proprietary software




You can use shell script to access your computer hard
ware and web servers .


You can user javacomm library to access you computer
hard ware and make URL request .


You can follow the new project
www.
mono
-
project.com
/
.


Or any other
Opensource

languages like python .


You can use a GSM/GPRS modem to direct access the
internet with out the need for computer.


Smart phone already have application to handle web
events and send notifications