RFID Reader

Overview

 This is a low frequency (125Khz) RFID Reader With Serial Output with at range of 8-12cm. It is a compact units with built in antenna and can be directly connected to the PC using RS232 protocol.

RFID Reader:

Features:

• Voltage: 5 vdc
• Current: <50ma
• Operating Frequency: 125 khz
• Read Distance: 10 cm
• Along with two RFID Cards.
• Serial and TTL Output

RFID Principles:

Many types of RFID exist, but at the highest level, we can divide RFID devices into two classes: active and passive. Active tags require a power source—they’re either connected to a powered infrastructure or use energy stored in an inte-grated battery. In the latter case, a tag’s lifetime is limited by the stored energy, balanced against the number of read operations the device must undergo. One example of an active tag is the transponder attached to an aircraft that identi-fies its national origin. Another example is a LoJack device attached to a car, which incorpo-rates cellular technology and a GPS to locate the car if stolen. However, batteries make the cost, size, and life-time of active tags impractical for the retail trade.Passive RFID is of interest because the tags don’t require batteries or maintenance. The tags also have an indefinite operational life and are small enough to fit into a practical adhesive label. A pas-sive tag consists of three parts: an antenna, a semiconductor chip attached to the antenna, and some form of encapsulation. The tag reader is responsible for pow-ering and communicating with a tag. The tag antenna captures energy and transfers the tag’s ID (the tag’s chip coordinates this process). The encap-sulation maintains the tag’s integrityand protects the antenna and chip from environmental conditions or reagents. The encapsulation could be a small glass vial  or a laminar plastic substrate with adhesive on one side to enable easy attachment to goods .  Two fundamentally different RFID design approaches exist for transferring power from the reader to the tag: mag-netic induction and electromagnetic (EM) wave capture. These two designs take advantage of the EM properties associated with an RF antenna—the near field and the far field. Both can transfer enough power to a remote tag to sustain its operation—typically between 10 W and 1 mW, depending on the tag type. (For comparison, the nominal power an Intel XScale processor consumes is approximately 500 mW, and an Intel Pentium 4 consumes up to 50 W.) Through various modulation techniques, near- and far-field-based sig-nals can also transmit and receive data.

Interfacing With 8051:

ARM Schematic:

ARM Code: 

For ARM code CLICK HERE

ATMEL Schematic:

ATMEL Code:

For ATMEL Code CLICK HERE

PIC Schematic:

PIC Code:

For PIC Code CLICK HERE