HOME AUTOMATION USING PC

possehastyMechanics

Nov 5, 2013 (3 years and 7 months ago)

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HOME AUTOMATION USING PC



DONE BY

RAJESHKUMAR S

SRI HARSHA D


The aim of the project is to control home appliances
like Television, Refrigerator, and Lights and other
home electrical appliances using a personal computer.


In this project a PC is interfaced with a micro
-
controller
and it is connected to relays to which the appliances
which are to be controlled are connected.


The micro
-
controller controls the relays for switching
the appliances, ON or OFF. Pre
-
defined symbols are sent
to the Microcontroller through RS232 cable


MAIN APPLICATION OF PROJECT

Home automation deals with providing a
network in the house which links


computers & peripheral equipment
.


smart chip bearing household appliances
like

dish washers, washing machines,
microwaves and other electrical
appliances.


sub
-
systems like Heating, Ventilation, Air
-
conditioning (HVAC), and security
systems.


What Is Home Automation




Micro
Controller


PCM


MAX
MAX

232

Power supply



ReLay


Driver

Relay

Relay


FAN

LIGHT

Power supply


BLOCK DIAGRAM

ADVANTAGES OF HOME AUTOMATION


Flexibility & Convenience



Security



Cost Saving



Remote Control

An embedded system can be defined as a computing
device that does a specific focused job.



Appliances such as the air
-
conditioner, VCD player,
DVD player, printer, fax machine, mobile phone etc. are
examples of embedded systems.


Each of these appliances will have a processor and
special hardware to meet the specific requirement of the
application along with the embedded software that is
executed by the processor for meeting that specific
requirement
.

EMBEDDED SYSTEM




MICROCONTROLLER VS MICROPROCESSOR


Microprocessors

and

microcontrollers

are

widely

used


in

embedded

systems

products
.



Microcontroller

is

a

programmable

device
.



A

microcontroller

has

a

CPU

in

addition

to

a

fixed


amount

of

RAM,

ROM,

I/O

ports

and

a

timer


embedded

all

on

a

single

chip
.



The

fixed

amount

of

on
-
chip

ROM,

RAM

and

number


of

I/O

ports

in

microcontrollers

makes

them

ideal

for


many

applications

in

which

cost

and

space

are

critical
.

INTERNAL

ARCHITECTURE

All upgraded microcontrollers use one of two basic design models
called Harvard and von
-
Neumann architecture

VON
-
NEUMANN

ARCHITECTURE


Microcontrollers using this architecture have only one memory block
and one 8
-
bit data bus.


As all data are exchanged by using these 8 lines, this bus is
overloaded and communication itself is very slow and inefficient


The CPU can either read an instruction or read/write
data from/to the memory.


Both cannot occur at the same time since the
instructions and data use the same bus system



HARVARD ARCHITECTURE


Microcontrollers using this architecture have two different data buses.


One is 8
-
bit wide and connects CPU to RAM memory.


Another one consists of several lines (12, 14 or 16) and connects CPU to ROM
memory

Accordingly, the CPU can read an instruction and perform a data memory
access at the same time


PIN Diagram Of Micro Controller Of AT89S8252


TIMERS



12D

OSCILLATOR

FREQUENCY

TR

TLX

THX

TFX

SFR’S USED IN TIMERS:




The
special

function registers used in timers are



TMOD Register




TCON Register



Timer(T0) & timer(T1) Registers



TMOD Register:


TMOD is dedicated solely to the two timers (T0 & T1).


The timer mode SFR is used to configure the mode of operation of each of the two
timers.


Using this SFR your program may configure each timer to be a 16
-
bit timer, or 13
bit timer, 8
-
bit auto reload timer,

or two separate timers.


It can consider as two duplicate 4
-
bit registers, each of which controls the action of
one of the timers.




The timer control SFR is used to configure and modify the way in
which the 8051’s two timers operate.


This SFR controls whether each of the two timers is running or
stopped and contains a flag to indicate that each timer has
overflowed. Additionally, some non
-
timer related bits are located
in TCON SFR.


These bits are used to configure the way in which the external
interrupt flags are activated, which are set when an external
interrupt occurs.



CONCLUSION

By using this project we control all the Electrical

a
ppliances of Home using Personal

Computer
via RS232 as

t
he communication medium between pc

and controller.



We are controlling the devices like light and fan and etc by sending

signals from the pc to controller.




This project gives exact concept of interfacing a high voltage

electrical device or DC / AC motor to

high sensitive personal computer system.