RFID Reader documentation v2.1

ManualsBrandsParallax ManualsBasic Stamp - Educational Boards & KitsRFID reader module

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RFID Card Reader, Serial (#28140)

RFID Card Reader, USB (#28340)

Introduction

Designed in cooperation with Grand Idea Studio (http://www.grandideastudio.com/), the Parallax Radio

Frequency Identification (RFID) Card Readers provide a low-cost solution to read passive RFID

transponder tags up to 4 inches away. The RFID Card Readers can be used in a wide variety of hobbyist

and commercial applications, including access control, automatic identification, robotics navigation,

inventory tracking, payment systems, and car immobilization. The RFID Card Reader is available in a TTL

version for microcontroller interfacing as well as a USB version for direct connection to a PC, Mac or Linux

computer.

Features

 Low-cost method for reading passive RFID transponder tags

 2400 bps serial interface

 Enable input allows module to be enabled/disabled by software

 USB version connects directly to PC, Mac or Linux machine and requires no additional wiring

 Bi-color LED for visual indication of status

Summary of content (11 pages)

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Web Site: www.parallax.com Forums: forums.parallax.com Sales: sales@parallax.com Technical: support@parallax.com Office: (916) 624-8333 Fax: (916) 624-8003 Sales: (888) 512-1024 Tech Support: (888) 997-8267 RFID Card Reader, Serial (#28140) RFID Card Reader, USB (#28340) Introduction Designed in cooperation with Grand Idea Studio (http://www.grandideastudio.
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RFID Compatibility The Parallax RFID Card Reader works exclusively with the EM Microelectronics-Marin SA EM4100-family of passive read-only transponder tags at 125 kHz. A variety of different tag types and styles exist with the most popular made available from Parallax. Each transponder tag contains a unique identifier (one of 240, or 1,099,511,627,776 possible combinations) that is read by the RFID Card Reader and transmitted to the host via a simple serial interface.
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Connecting and Testing (Serial Version) The Parallax RFID Card Reader serial version can be integrated into any microcontroller design using only four connections (VCC, /ENABLE, SOUT, GND). Use the following circuit for connecting the Parallax RFID Card Reader to the BASIC Stamp microcontroller. Pin Pin Name Type 1 VCC P Function System power, +5V DC input. Module enable pin. Active LOW digital input. Bring this pin LOW to 2 /ENABLE I enable the RFID reader and activate the antenna.
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Connecting and Testing (USB Version) The Parallax RFID Card Reader USB can be connected to any PC, Mac or Linux computer with a USB port and the appropriate FTDI USB drivers installed. The drivers should be installed prior to connecting the hardware to your computer. The drivers for PC can be obtained from the Parallax website by going to the Support tab and selecting Downloads/FTDI USB Drivers. Other drivers, including Mac and Linux can be downloaded from the FTDI website at the following URL. http://www.
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Interference The Parallax RFID Card Reader, like many RF devices, may experience RF noise in its frequency range. This may cause the reader to transmit a spurious tag response when no tag is near the unit. This will not affect most uses of the RFID Card Reader. To completely prevent spurious responses, it is recommended to simply read two responses in a row within a given amount of time (e.g. 1 second) to ensure that you are reading a valid tag and not a “tag” generated by noise.
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waves generated by the reader in order to transmit its data back to the reader. The reader receives the modulated waves and converts them into digital data. There are two major types of tag technologies. "Passive tags" are tags that do not contain their own power source or transmitter. When radio waves from the reader reach the chip’s antenna, the energy is converted by the antenna into electricity that can power up the microchip in the tag (known as "parasitic power").
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' -----[ I/O Definitions ]------------------------------------------------SYMBOL SYMBOL SYMBOL SYMBOL Enable RX Spkr Latch = = = = 0 1 2 3 ' ' ' ' low = reader on serial from reader speaker output lock/latch control ' -----[ Constants ]------------------------------------------------------SYMBOL LastTag = 2 ' 3 tags; 0 to 2 ' -----[ Variables ]------------------------------------------------------SYMBOL SYMBOL SYMBOL SYMBOL SYMBOL SYMBOL SYMBOL SYMBOL SYMBOL SYMBOL tag0 tag1 tag2 tag3 tag4 tag5 t
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pntr = tagNum * IF char <> tag1 pntr = tagNum * IF char <> tag2 pntr = tagNum * IF char <> tag3 pntr = tagNum * IF char <> tag4 pntr = tagNum * IF char <> tag5 pntr = tagNum * IF char <> tag6 pntr = tagNum * IF char <> tag7 pntr = tagNum * IF char <> tag8 pntr = tagNum * IF char <> tag9 GOTO Tag_Found Bad_Char: NEXT 10 + THEN 10 + THEN 10 + THEN 10 + THEN 10 + THEN 10 + THEN 10 + THEN 10 + THEN 10 + THEN 1 : READ Bad_Char 2 : READ Bad_Char 3 : READ Bad_Char 4 : READ Bad_Char 5 : READ Bad_Char 6 : READ Bad
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' -----[ Revision History ]-----------------------------------------------' -----[ I/O Definitions ]------------------------------------------------Enable RX Spkr Latch PIN PIN PIN PIN 0 1 2 3 ' ' ' ' low = reader on serial from reader speaker output lock/latch control ' -----[ Constants ]------------------------------------------------------#SELECT $STAMP #CASE BS2, BS2E, BS2PE T1200 CON 813 T2400 CON 396 T4800 CON 188 T9600 CON 84 T19K2 CON 32 TMidi CON 12 T38K4 CON 6 #CASE BS2SX, BS2P T1200 CON 2063
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LastTag CON 3 #DEFINE __No_SPRAM = ($STAMP < BS2P) ' does module have SPRAM? ' -----[ Variables ]------------------------------------------------------#IF __No_SPRAM #THEN buf VAR #ELSE chkChar VAR #ENDIF tagNum idx char VAR VAR VAR Byte(10) ' RFID bytes buffer Byte ' character to test Nib Byte Byte ' from EEPROM table ' tag byte index ' character from table ' -----[ EEPROM Data ]----------------------------------------------------Tag1 Tag2 Tag3 DATA DATA DATA "0F0184F20B" "0F01D9D263" "04129
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Bad_Char: NEXT ' try next tag Bad_Tag: tagNum = 0 GOSUB Show_Name FREQOUT Spkr, 1000 */ TmAdj, 115 */ FrAdj PAUSE 1000 GOTO Main ' print message ' groan Tag_Found: GOSUB Show_Name HIGH Latch FREQOUT Spkr, 2000 */ TmAdj, 880 */ FrAdj LOW Latch GOTO Main ' ' ' ' print name remove latch beep restore latch END ' -----[ Subroutines ]----------------------------------------------------' Prints name associated with RFID tag Show_Name: DEBUG DEC tagNum, ": " LOOKUP tagNum, [Name0, Name1, Name2, Name3], idx D