15-06-2012, 11:06 AM
ADVANCED SECURITY SYSTEM USING DTMF
ADVANCED SECURITY SYSTEM USING DTMF.docx (Size: 553.08 KB / Downloads: 51)
ABSTRACT
In the present days the field of electronics has took a lot of developments and the security services in presence and in the absence of manpower. The home electrical apparatus control system is one of the developments made to control the process as well as to secure the industry automatically.
The home electrical device operating system deals with all the problems occurred due to the physical circumstances and can effectively control them and let the industry to be in safe mode. It is an embedded project and has the micro controller as controlling processor. In these we are using four sensors to observe the circumstances. The Smoke sensors will always look for the smoke sensing and will inform to micro controller in case of any Smoke is observed. The temperature sensor maintains the heat at the specified level. Light intensity sensor is used to sense the Light and the humidity sensor is used to observe the humidity in the air. According to the signals given by these Sensors the Micro controller will activate. Including with this security some voice messages is delivered to the administrator, by connecting the mobile to the board (Hardware) according to the sensing values. Thus autodialing is possible.
This project is intended to design a system that supports wireless communication-using Blue tooth technology. The signal coming out of the micro controller will be encoded and the data will be transmitted over the free space (Channel).This signal is received by the receiver which is connected to the power control system of the industry. This signal is decoded and given to the micro controller. This controller controls the appliances according to the data received.
INTRODUCTION TO DTMF
DTMF: DTMF stands for Dual-Tone-Multi-Frequency.
DTMF standard was developed by Bell Laboratories.
DTMF is used for telecommunication signaling over analog telephone lines in the voice frequency band between telephone handsets and other communication devices and the switching center.
• DTMF is used for tone dialing using push buttons.
• whenever we press push buttons on telephone handsets two pre assigned frequencies will transmit and we can assign some functionality to that key or group of keys by which can control remote devices using DTMF.
• The DTMF is a popular signaling method between telephones and switching centers.
• DTMF is also used for signaling between the Telephone network and computer networks.
• The DTMF signals are Transmitted over a telephone line
• Uses speech frequency signals.
• DTMF signals are the superposition of 2 sine waves with different frequencies.
• Dual Tone Multifrequency System (DTMF), is a touch pad dialling tone.
• DTMF standard is used in touch tone telephones and voice mail systems.
• Allow users and devices to dial at much higher rate because of the uniformity of numbers.
• Each digit corresponds to a high frequency and a low frequency
• Both are transmitted simultaneously.
• Works by sending two sinusoids for each symbol pressed on the telephone keypad.
• The tones are divided into two groups:
• Low group: 697 Hz, 770 Hz, 852 Hz, 941 Hz.
• High group: 1209 Hz, 1336 Hz, 1477 Hz.
OVERVIEW OF PROJECT :
The advanced security system architecture we proposed contains many subsystems. Here we are using 8051 microcontroller kit to interface two devices and other is mobile phone-1.When we give commands from mobile phone-2 to phone-1 the controller kit receives the commands and performs the operation.The operation is depending on the command getting into the uC.
The application is not only restricted to remote operation, it operate directly also, like we are at home then we will give commands directly through the keypad to the microcontroller kit for switching the devices at home with a security code.
Hardware Implementation:
Power Supply:
Here we used +12V and +5V dc power supply. The main function of this block is to provide the required amount of voltage to essential circuits. +12 voltage is given. +12V is given to relay driver. To get the +5V dc power supply we have used here IC 7805, which provides the +5V dc regulated power supply.
89C52 Microcontroller:
It is a low-power, high performance CMOS 8-bit microcontroller with 8KB 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 MCS-51TM instruction set and pin out. 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 hip, the Atmel AT89S52 is a powerful microcontroller, which provides a highly flexible and cost effective solution to so many embedded control applications.