Posts: 3,561
Threads: 923
Joined: Sep 2010
[attachment=7958]
INTRODUCTION
RFID based systems are going to revolutionize the entire library automation systems. In this project we are going to develop library automation system, which will track the books, whether they are issued or they are in library, so that library user will get the instant information.``
RFID can be used library circulation operations and theft detection systems. RFID-based systems move beyond security to become tracking systems that combine security with more efficient tracking of materials throughout the library, including easier and faster charge and discharge, inventorying, and materials handling.
This technology helps librarians reduce valuable staff time spent scanning barcodes while charging and discharging items. RFID is a combination of radio -frequency-based technology and microchip technology. The information contained on microchips in the tags affixed to library materials is read using radio frequency technology, regardless of item orientation or alignment (i.e., the technology does not require line-of-sight or a fixed plane to read tags as do traditional theft detection systems). The RFID gates at the library exit(s) can be as wide as four feet because the tags can be read at a distance of up to two feet by each of two parallel exit gate sensors.
Block diagram description:
The block diagram (Fig 2.1) consists of microcontroller interfaced with an RFID module by an RS232, microcontroller is not directly connected to rs232 because RS-232 signal levels are far too high TTL electronics, and the negative RS-232 voltage for high can’t be handled at all by computer logic. To receive serial data from an RS-232 interface the voltage has to be reduced. Also the low and high voltage level has to be inverted.
This level converter uses a Max232 and five capacitors. The max232 is quite cheap (less than 5 dollars) or if you are lucky you can get a free sample from Maxim.
The MAX232 from Maxim was the first IC which in one package contains the necessary drivers and receivers to adapt the RS-232 signal voltage levels to TTL logic. It became popular, because it just needs one voltage (+5V or +3.3V) and generates the necessary RS-232 voltage levels.
Book with RFID, the block diagram is nothing but the rfid tag attached to the book which contains a chip and antenna, RFID reader also has an antenna which reads the information from the tag
MICRO CONTROLLER VERSUS MICRO PROCESSOR:
What is the difference between a Microprocessor and Microcontroller? By microprocessor is meant the general purpose Microprocessors such as Intel's X86 family (8086, 80286, 80386, 80486, and the Pentium) or Motorola's 680X0 family (68000, 68010, 68020, 68030, 68040, etc). These microprocessors contain no RAM, no ROM, and no I/O ports on the chip itself. For this reason, they are commonly referred to as general-purpose Microprocessors.
A system designer using a general-purpose microprocessor such as the Pentium or the 68040 must add RAM, ROM, I/O ports, and timers externally to make them functional. Although the addition of external RAM, ROM, and I/O ports makes these systems bulkier and much more expensive, they have the advantage of versatility such that the designer can decide on the amount of RAM, ROM and I/O ports needed to fit the task at hand. This is not the case with Microcontrollers.
A Microcontroller has a CPU (a microprocessor) in addition to a fixed amount of RAM, ROM, I/O ports, and a timer all on a single chip. In other words, the processor, the RAM, ROM, I/O ports and the timer are all embedded together on one chip; therefore, the designer cannot add any external memory, I/O ports, or timer to it. 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.
In many applications, for example a TV remote control, there is no need for the computing power of a 486 or even an 8086 microprocessor. These applications most often require some I/O operations to read signals and turn on and off certain bits.
SERIAL PORTS:
Each 8051 microcomputer contains a high speed full duplex (means you can simultaneously use the same port for both transmitting and receiving purposes) serial port which is software configurable in 4 basic modes: 8 bit UART; 9 bit UART; inter processor Communications page link or as shift register I/O expander.
For the standard serial communication facility, 8051 can be programmed for UART operations and can be connected with regular personal computers, teletype writers, modem at data rates between 122 bauds and 31 kilo bauds. Getting this facility is made very simple using simple routines with option to elect even or odd parity. You can also establish a kind of Inter processor communication facility among many microcomputers in a distributed environment with automatic recognition of address/data. Apart from all above, you can also get super fast I/O lines using low cost simple TTL or CMOS shift registers.
RFID INTRODUCTION:
RFID (Radio Frequency Identification) allows an item, for example a library book, to be tracked and communicated with by radio waves. This technology is similar in concept to a cell phone. RFID is a broad term for technologies that use radio waves to automatically identify people or objects.
There are several methods of identification, but the most common is to store a serial number that identifies a person or object, and perhaps other information, on a microchip that is attached to an antenna (the chip and the antenna together are called an RFID transponder or an RFID tag). The antenna enables the chip to transmit the identification information to a reader. The reader converts the radio waves reflected back from the RFID tag into digital information that can then be passed on to computers that can make use of it .
The heart of the system is the RFID tag, which can be fixed inside a book's back cover or directly onto CDs and videos. This tag is equipped with a programmable chip and an antenna. Each paper-thin tag contains an engraved antenna and a microchip with a capacity of at least 64 bits.
History of RFID tags
In 1946 Léon Theremin invented an espionage tool for the Soviet Union which retransmitted incident radio waves with audio information. Sound waves vibrated a diaphragm which slightly altered the shape of the resonator, which modulated the reflected radio frequency. Even though this device was a passive covert listening device, not an identification tag, it has been attributed as the first known device and a predecessor to RFID technology. The technology used in RFID has been around since the early 1920s according to one source (although the same source states that RFID systems have been around just since the late 1960s).
Similar technology, such as the IFF transponder invented by the United Kingdom in 1939, was routinely used by the allies in World War II to identify airplanes as friend or foe. Transponders are still used by military and commercial aircraft to this day.
Another early work exploring RFID is the landmark 1948 paper by Harry Stockman, titled "Communication by Means of Reflected Power" (Proceedings of the IRE, pp 1196–1204, October 1948). Stockman predicted that "…considerable research and development work has to be done before the remaining basic problems in reflected-power communication are solved, and before the field of useful applications is explored."
Mario Cardullo's U.S. Patent 3,713,148 in 1973 was the first true ancestor of modern RFID; a passive radio transponder with memory. The initial device was passive, powered by the interrogating signal, and was demonstrated in 1971 to the New York Port Authority and other potential users and consisted of a transponder with 16 bit memory for use as a toll device.
The basic Cardullo patent covers the use of RF, sound and light as transmission medium. The original business plan presented to investors in 1969 showed uses in transportation (automotive vehicle identification, automatic toll system, electronic license plate, electronic manifest, vehicle routing, vehicle performance monitoring), banking (electronic check book, electronic credit card), security (personnel identification, automatic gates, surveillance) and medical (identification, patient history).
A very early demonstration of reflected power (modulated backscatter) RFID tags, both passive and semi-passive, was done by Steven Depp, Alfred Koelle and Robert Freyman at the Los Alamos Scientific Laboratory in 1973. The portable system operated at 915 MHz and used 12 bit tags. This technique is used by the majority of today's UHF and microwave RFID tags.
