RFID reader documentation

Parallax, Inc. • RFID Reader Module (#28140) •Updated 09/2005 v1.1 Page 6

manufacturing cost), the Parallax RFID Reader Module's antenna was designed with a specific inductance

and "Q" factor for 170kHz RFID operation at a tag read distance of up to 1 ¾” - 3” inches.

Example Code

The following code examples read tags from a RFID Reader Module and compare the values to known

tags (stored in an EEPROM table).

' =========================================================================

' File....... RFID.BS1

' Purpose.... RFID Tag Reader / Simple Security System

' E-mail..... support@parallax.com

' Started....

' Updated.... 07 FEB 2005

' {$STAMP BS1}

' {$PBASIC 1.0}

' =========================================================================

' -----[ Program Description ]---------------------------------------------

' Reads tags from a Parallax RFID reader and compares to known tags (stored

' in EEPROM table). If tag is found, the program will disable a lock.

' -----[ Revision History ]------------------------------------------------

' -----[ I/O Definitions ]-------------------------------------------------

SYMBOL Enable = 0 ' low = reader on

SYMBOL RX = 1 ' serial from reader

SYMBOL Spkr = 2 ' speaker output

SYMBOL Latch = 3 ' lock/latch control

' -----[ Constants ]-------------------------------------------------------

SYMBOL LastTag = 2 ' 3 tags; 0 to 2

' -----[ Variables ]-------------------------------------------------------

SYMBOL tag0 = B0 ' RFID bytes buffer

SYMBOL tag1 = B1

SYMBOL tag2 = B2

SYMBOL tag3 = B3

SYMBOL tag4 = B4

SYMBOL tag5 = B5

SYMBOL tag6 = B6

SYMBOL tag7 = B7

SYMBOL tag8 = B8

SYMBOL tag9 = B9

SYMBOL tagNum = B10 ' from EEPROM table

SYMBOL pntr = B11 ' pointer to char in table

SYMBOL char = B12 ' character from table