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
Thread
• 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 As 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).
UBRR : set baud rate
UDR : transmit receive data
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.
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.monoproject.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