HOME AUTOMATION USING PC
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
and it is connected to relays to which the appliances
which are to be controlled are connected.
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
dish washers, washing machines,
microwaves and other electrical
systems like Heating, Ventilation, Air
conditioning (HVAC), and security
What Is Home Automation
ADVANTAGES OF HOME AUTOMATION
Flexibility & Convenience
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
MICROCONTROLLER VS MICROPROCESSOR
All upgraded microcontrollers use one of two basic design models
called Harvard and von
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
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
Accordingly, the CPU can read an instruction and perform a data memory
access at the same time
PIN Diagram Of Micro Controller Of AT89S8252
SFR’S USED IN TIMERS:
function registers used in timers are
Timer(T0) & timer(T1) Registers
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
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
By using this project we control all the Electrical
ppliances of Home using Personal
via RS232 as
he communication medium between pc
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.