HOME AUTOMATION USING PC

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HOME AUTOMATION USING PC

DONE BY RAJESHKUMAR S SRI HARSHA D
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MAIN APPLICATION OF PROJECT
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
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What Is Home Automation

• 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.

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BLOCK DIAGRAM
Power supply
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ADVANTAGES OF HOME AUTOMATION

• Flexibility Convenience
• Security
• Cost Saving
• Remote Control

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EMBEDDED SYSTEM
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.
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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.
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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
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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
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PIN Diagram Of Micro
Controller Of AT89S8252
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TIMERS

• SFRS USED IN TIMERS
• The special
  function registers used in timers are
• TMOD Register
• TCON Register
• Timer(T0)
  timer(T1) Registers

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• 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.

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TCON Register

• 
  
• The timer control SFR is used to configure and
  modify the way in which the 8051s 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.

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CONCLUSION
By using this project we control all the
Electrical appliances of Home using Personal
Computer via RS232 as the 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.
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Thank You