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).

RCX: Data receive completeUDRE:Ready for transitionU2X : double the transition baud rate

RXEN: Enable Receive DataTXEN: Enable Transmit Data

UCPOL: Using the USART as synchronous or a synchronous UCSZ0/1:select the Size Of data(5,6,7,8)bitsUSBS: number of stop bit UPM0/1:parity (none, odd , even)UMSEL /URSEL : put to Zero.

UBRR : set baud rateUDR : 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