GENERIC CONTROL OF ELECTRICAL

ENVIRONMENT THROUGH A WEBPAGE

- IT Acumens. COM

AIM:

The aim of the project is to control electrical devices from a remote location through a web page.

SOFTWARE REQUIRED

• Java 2 Enterprise Edition(J2EE)

• Java Development Kit (JDK1.3)

• Apache Tomcat Server 1.4.1

• Internet Explorer

• Microsoft Access

• Microsoft Word( for documentation)

HARDWARE REQUIRED

• Pentium III processor

• 64 MB RAM

• 10 GB Hard Disk

• Operating system windows 98

• PC Add-On card with PIA chip(s)

• An External port board.

• A dedicated designed interface

SCOPE OF THE PROJECT

CONTROL THROUGH IR

Range is limited.Line of sight

CONTROL THROUGH MICROWAVE

Transmitter & Receiver are costly.

DESCRIPTION

The electrical devices that are to be controlled are connected to the home PC through a designed dedicated interface.The status word of the devices are posted to the PC through the PIA present in the CPU of the home PC.The status word is then uploaded to the web server.

At the server the individual status of the devices are decoded and posted to the web page.A remote user logs in and checks the current status of the devices,if required the user changes the status of the devices.The changed status is then posted to the web server.The control word is then encoded and posted to the home PC.The changed status of the devices are reflected.

STATUS DETECTING CIRCUIT

CONTROL CIRCUIT

8255 CHIP

• The 8255 chip is called a Programmable Interface Adapter(PIA).

• The three buses used for the interface are the address bus,data bus and the control bus.

• The 8255 contains three individual I/O ports.

• The microprocessor connects to certain pins on the 8255.

• Each port can be made to function either as Input port or an Output port by setting the control word.

• Block B provides the logic for reading and writing to each port of the chip.

The electrical status of the devices is retrieved through the C++ program using the port-based instructions.

The port-based instructions are•       _inp (port number)•       _outp (port number, value)

_inp is used to read the value from the port and

_outp is used to write the value to the port.

START

SELECT

THE DEVICES

TO BE CONTROL

CONNECT THE DEVICES TO THE

HARDWARE INTERFACE

A

CONNECT THE INTERFACE TO THE PIA IN THE PC

USING THE PORTBASED INSTRUCTIONS RETRIEVE

THE STATUS WORD

IS THERE ACHANGE

IN STATUS WORD

A

UPLOAD THE CHANGED

STATUS WORD TO

THE SERVER

THE STATUS WORD IS

DECODED AND IT IS

STORED IN DATABASE

IN THE SERVER

THE REMOTE USERS

AUTHENTICATION IS

CHECKED

IS THE USER A

AUTHENTICATED

USER

IS THE USER

ADMINISTRATOR

DIRECT THE USER

TO A

RE-LOGIN PAGE

YES

DOES

THE USER HAVE WRITE

PERMISSIONDIRECTED

TO THE ADMINISTRATOR PAGE

NO

NO

C

DIRECT TO THE

CHANGE STATUS PAGE

DIRECT THE USER

TO THE DISPLAY

STATUS PAGE

O

THE USER CHANGES

THE STATUS AND

SUBMITS THE FORM

THE ENCODED VALUE

IS WRITTEN IN

THE SERVER

C

THE CONTROL WORD

IS POSTED TO

THE HOME PC

THE CONTROL WORD

IS SENT TO THE

OUTPUT PORT OF PIA

THE CHANGED STATUS

IS REFLECTED ON

THE DEVICES AT HOME.

STOP

O

MODULES

• Retrieving status word from the electrical device.

• Posting the control word to the web server.

• User authentication and display of current status.

• User changing the status of the required device.

• Control word stored in the home PC.

• Reflecting the changed status on device.

ACQUIRING DEVICE STATUS• The electrical devices are connected to the

interface designed.

• The interface is connected to the home PC through a Peripheral Interface Adapter.

• The Status word is obtained through a flat cable connected from the PC to the port board.

• The value is then posted to the server.

DECODING

• A Servlet program is written to decode the status word.

• The current status of the device are posted to the web page.

ADMINISTRATOR

• The administrator has the rights to add/delete the users from/to the list.

• The administrator categorizes the users with two permissions

* Read permission.

* Read /write permission.

REMOTE USER

• Authenticated users are allowed to access the web page.

• The users with read permission can only view the current status of the device.

• The users with read/write permission can view as well as change the status of the device.

• The changed status is stored in the web server’s database.

TRANSACTION OF DATA

ENCODING CONTROL WORD

• The status stored in the database are encoded using a servlet program.

• The encoded value is a decimal number which varies from 0 to 255.

• The encoded control word is posted from the web server to the home PC.

AT THE HOME PC

• The encoded control word is send to the interface through a java program.

• Decoding is done in the interface as a result of which individual device status are changed.

OUTPUT SCREENS

LOGIN SCREEN

CURRENT STATUS

REQUIRED STATUS

DATA STORED