FINGER PRINT SECURITY
The general trend of human nature always longing for security Physically, Mentally and Socially. Fingerprint based security access control and time attendance systems are used for all kinds of office and service sector operations in the day today environment. Fingerprint System based access control is more secured as compared to the conventional swipe card or ID cards because of the exclusive fingerprint for every entity.
Fingerprint Security Systems have fascinated people for centuries. They have been used as a method of personal identification since ancient times. The two key aspects of most of the Fingerprint System biometric solutions are Finger ...view middle of the document...
Another kind of Fingerprint System is the scanner using ultrasound. The process involves high frequency sound to identify a fingerprint. An advantage of ultrasound sensors is that they are not affected by external hindrances like dirt on a finger. Thermal Fingerprint Security System Scanners work by measuring temperature differences used for a variety of security and data-collection purposes, from identifying prisoners to allowing access to information or high-security areas.
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...