RE: password based door locking system
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Now a day’s most of the systems are automated in order to face new challenges and present day requirements to achieve good results. Automated systems have less manual operations, so that the flexibility, reliabilities are high and accurate. Hence every field prefers automated control systems, especially in the field of electronics.
The goal of the project is to develop a unique system through mobile technology which can control various units of the houses, industries, and also provides a security system. The various appliances can be utilized by managing them remotely by using GSM technology, which enables the user to remotely control the operations of the appliances. Just by pressing keypad of remote telephone the user can perform ON/OFF operations on the appliances.
The project also exhibits low cost home security system which is widely employed in our daily life. This system is designed to prevent the opening of the door by unauthorized persons. The structure of home security system contains a matrix key pad, the door latch opener and a GSM modem for the security dial up interfaced to the microcontroller. The keypad interfaced to the controller is used as the password entry system to open/close the door. As soon as the user enters the correct password, the door lock opens. If the password entered is incorrect, then a security alarm is rung and at the same time it enables the security dial-up through the GSM modem interfaced to the microcontroller.
The GSM modem uses the UART interface to the controller. When the unauthorized person gives an invalid password then the controller uses the modem to inform the owner. The modem receives security dial up number and the message from the controller and it uses the GSM network to transmit the message. There is a socket in the modem to insert the sim card to use the GSM network. The destination mobile number and the password are stored in the EEPROM of the controller.
Security is prime concern in our day-to-day life. Every one
wants to be asmuch as secure as to be possible. An access control systems forms a vital link in asecurity chain. The micro controller based digital lock presented here is an accesscontrol system that allows only authorized persons to access a restricted area. Thissystem is best suitable for corporate offices, ATMs and home security.
The system comprises a small electronic unit with a numeric keypad, which isfixed out side the entry door to control a solenoid-operated lock with the help of a stepper motor. When an authorized person enters predetermined user ID and password
via the keypad, the stepper motor is operated for a limited time to unlatch the solenoid-operated lock so the door can be open. At the end of preset delay, the stepper motor is operated in reverse direction and the door gets locked again.When the code has been incorrectly entered three times in a row, the code lock will switch to block mode. This function thwarts any attempt by ‘hackers’ to quickly try a large number of codes in a sequence. If the user forgets his password, the code lock can be accessed by a unique 10 digit administrator password. The secret code can be changed any time after entering the current code (Master code).
. A BRIEF INTRODUCTION TO 8051 MICROCONTROLLER-:
When we have to learn about a new computer we have to familiarize about the machine capability we are using, and we can do it by studying the internal hardware design (devices architecture), and also to know about the size, number and the size of the registers.
A microcontroller is a single chip that contains the processor (the CPU), non-volatile memory for the program (ROM or flash), volatile memory for input and output (RAM), a clock and an I/O control unit. Also called a "computer on a chip," billions of microcontroller units (MCUs) are embedded each year in a myriad of products from toys to appliances to automobiles. For example, a single vehicle can use 70 or more microcontrollers. The following picture describes a general block diagram of microcontroller.
AT89S52: The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory pro-grammer. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller, which provides a highly flexible and cost-effective solution to many, embedded control applications. The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM con-tents but freezes the oscillator, disabling all other chip functions until the next interrupt