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