Circuit diagram of mobile controlled home appliances
Components required for home automation
1. Regulated power supply
2. DTMF decoder IC (M-8870)
3. Resistors (100Ω; 100kΩ; 70kΩ; 390kΩ)
4. Capacitors (0.1µFx 2)
5. Crystal oscillator (3.579545MHz)
6. IC 7474 D flip flop
7. BC547 Transistor
8. 6V relay
9. DTMF BASED HOME APPLIANCES CONTROL
INTRODUCTION:
Today’s the demand for better home security systems has drifted over to a need for home
automation. Not only does a home need to be secure but home appliances need a more refined
control system. Home appliances should not be limited to only local control. There needs to be
a simple and elegant way to avoid this type of situation and allow people the freedom of
having complete control of their house from anywhere. With this fact in mind we have build a
project for the home automation controls. The key to this control system will be the use of a
telephone for a two way communication path to the central control unit.
With this system, it is possible to operate domestic electrical devices safety by using public or
mobile phones from any places all over the world.
The basic idea of this project is to take advantage of the vast network of telephone lines and
the proliferation of cell phones to extend human’s reach and possibilities. The system, through
telephone networks, connects the user home appliances at home and gives him/her the ability
to switch them ON or OFF. The user dials the home telephone number like an ordinary
telephone call. The telephone at home rings and if nobody picks the call, then the system picks
up the call. The system then asks for the password. The user enters the password. Once the
password is entered, the user will be offered a voice menu and asked to choose from that
menu. The user chooses an item from the menu by pressing a button on the phone keypad.
Pressing a button on the phone generates a DTMF signal which, through the telephone network,
will reach the system at home. The system will recognize the received signal and based on that
will switch on/off the chosen appliance.
This project uses DTMF technology for the controls.
DTMF, better known as touch-tone, is a system of signal tones used in telecommunications.
Applications include voice mail, help desks, telephone banking, etc.
There are twelve DTMF signals, each of which is made up of two tones from the following
selection: 697 Hz, 770 Hz, 852 Hz, 941 Hz, 1209 Hz, 1336 Hz, 1477 Hz. The tones are divided
AIM & OBJECTIVE
AIM:-
1.To make a CELL-PHONE operated DTMF HOME AUTOMATION SYSTEM.
2.To make a home security system.
3.To prepare remote sensing security system.
OBJECTIVE:-
In the view today society demand it is essential to made a better home security systems. Not
only does a home need to be secure but home appliances need a more refined control system.
Home appliances should not be limited to only local control.
From the above point of view we have tried to prepare a model for home automation control
and security system.
1
Buzzer 5V 1
LCD base - 1
LCD 5V 1
IC base 40 pin
20 pin
18 pin
1
1
1
General purpose PCB 14x9 cm 1
11.
12. HOME AUTOMATION MODEL
13.
14. The core of the project is the 8051 microcontroller; it will determine what actions need to
be sent out to the rest of the system. The microcontroller will determine when each sub
part needs to be activated .Other parts include the Phone interface, the decoder and the
appliance connected through the relay.
15.
16.
17. Phone Interface:
18.
The telephone line is hooked to the another phone attached to the system This will
communicate directly with the microcontroller through the CM8870 decoder which decodes all
16 DTMF tone pairs into a four bit code.
19. CM8870/70C (DTMF decoder):
20.
CM8870/70C is a Full DTMF receiver, uses less than 35mW power consumption, uses quartz
crystal or ceramic resonators, has adjustable acquisition and release times, works in Industrial
temperature range and is available in 18-pin DIP, 18-pin DIP EIAJ, 18-pin SOIC, 20-pin
PLCC.
.
Pin Diagram of CM8870C
21. ATMEL AT89C52 (Microcontroller):
22.
he AT89C52 is a low-power, high-performance CMOS 8-bit microcomputer with 8K Flash bytes
of Flash programmable and erasable read only memory (PEROM). The device is manufactured
using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-
standard 80C51 and 80C52 instruction set and pinout. The on-chip Flash allows the program
memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer.
By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C52 is a
powerful microcomputer which provides a highly-flexible and cost-effective solution to many
embedded control applications.
Pin Diagram of AT89C52
23. 1N 4007 DIODE:
24.
It has the following features:
1. Low forward voltage drop
2. High surge current capacity
3. Low reverse leakage current
4. V(rrm) = peak repetitive reverse voltage = 1000 V
5. I (fsm) = average rectified forward current = 1A
6. V(f) = forward voltage = 1.1 V
BC 548 TRANSISTOR:
It is general purpose NPN transistor, having the following features:
1. Vcbo = 30 V
2. Ic = 100 mA
3. Ptotal = 50 mW
4. f = 300 MHz
25. LM7805 DC POWER REGULATOR :
26.
It has the following characteristics:
1. Operating current - 1 A
2. Operating voltages - 5 , 6 , 8 , 9 Vetc
27. RF TAG:
28.
It has a 4-bit data input
29. 16 X 2 LCD :
30.
It has 16 characters, 2-line display and is used for general purpose.
31. IC 74LS147 :
32.
It is a 10 to 4 line priority encoder. It encodes 10-line decimal to 4-line BCD.
33. LCD (JHD162A series)
34.
Display Content: 16 Char x 2 Row
Character Dots: 5 x 8
Driving mode: 1/16D
Available Types:
Reflective with EL or Led Backlight
EL/100 V AC 400 Hz
LED/4.2 V DC
LCD pin Diagram:
35. RELAY:
A relay is a type of electrically operated switch which is controlled by an electronic circuit. Within
the relay is a coil of wire which generates a magnetic field when a current flows through it. If
sufficient current at the correct voltage flows through the coil, the generated magnetic field
attracts a metal lever which changes the position of the switch.
The advantage of a relay is that it permits a low voltage DC circuit to control a completely
separate high-power circuit - for example a 240V AC mains electricity powered appliance.
CIRCUIT DIAGRAM:
CODE OBJECTIVE
Make pin P2.5 = 1 when key ‘1’ is pressed and make P2.5=0 when key ‘2’ is pressed.
ORG 0000h
MOV P2, #0FFH //Configure P2 as Input
Main:
JNB P2.0, $ //Wait till a High Pulse is received from StD
MOV A, P2 //Take data in from the output Latch
ANL A, #1EH //Mask the unwanted bits
RRC A
CJNE A, #01H, C1_MAIN //CHECK IF KEY PRESSED IS ‘1’
SETB P2.5 //IF YES P2.5=1
JMP Main
C1_MAIN:
CJNE A, #01H, MAIN //CHECK IF KEY PRESSED IS ‘2’
CLR P2.5 //IF YES P2.5=0
JMP Main
36.
1.