Web Site: www.parallax.com Office: (916) 624-8333 Forums: forums.parallax.com Fax: (916) 624-8003 Sales: sales parallax.com Sales: (888) 512-1024 Technical: support parallax.com Tech Support: (888) 997-8267 RFID Read/Write Module, Serial ( 28440) Designed in cooperation with Grand Idea Studio (www.grandideastudio.com), the Parallax Radio Frequency Identification (RFID) Read/Write Module provides a low-cost solution to read and write passive RFID transponder tags up to 3 inches away. The RFID transponder tags provide a unique serial number and can store up to 116 bytes of user data, which can be password protected to allow only authorized access. The RFID Read/Write Module can be used in a wide variety of hobbyist and commercial applications, including access control, user identification, robotics navigation, inventory tracking, payment systems, car immobilization, and manufacturing automation. Features y Low-cost method for reading and writing passive, 125 kHz RFID transponder tags y Up to 116 bytes of user data storage on a single tag y Optional security features prevent tag from being read or written without password y Bi-color LED for visual indication of status Key Specifications y Power requirements: +5 VDC < 10 mA idle, approx. 100-200 mA active y Communication: asynchronous serial 9600 bps, (8N1) 5 V TTL-level, non-inverted y Dimensions: 3.25 x 2.45 in (8.26 x 6.2 cm) RFID Tag Compatibility The RFID Read/Write Module works exclusively with the EM Microelectronics EM4x50 1kbit R/W transponder tags. A variety of different tag types and styles exist, with the most popular ones made available from Parallax. 32 Each tag contains a unique, read-only serial number (one of 2 , or 4,294,967,296 possible combinations) and 116 bytes of user data area stored in a non-volatile EEPROM (Electrically Erasable Read Only Memory). The user data area can be optionally secured with a 32-bit password to allow only authorized read and write operations. The RFID Read/Write Module provides, with a single command, legacy support for the EM Microelectronics EM4100 read-only tags that are used with Parallaxs RFID Card Reader Serial ( 28140) and USB ( 28340). Copyright Parallax Inc. RFID Read/Write Module, Serial ( 28440) v1.0 6/29/2010 Page 1 of 10 Connections The RFID Read/Write Module easily interfaces to any host microcontroller using only four connections (VCC, SIN, SOUT, GND). Pin Pin Name Type Function 1 VCC P System power. +5V DC input. Serial input from host. TTL-level interface, 9600 bps, 8 data 2 SIN I bits, no parity, 1 stop bit. Serial output to host. TTL-level interface, 9600 bps, 8 data bits, 3 SOUT O no parity, 1 stop bit. System ground. Connect to power supplys ground (GND) 4 GROUND G terminal. Note: Type: I = Input, O = Output, P = Power, G = Ground Use the following example circuit for connecting the Parallax RFID Read/Write Module: Copyright Parallax Inc. RFID Read/Write Module, Serial ( 28440) v1.0 6/29/2010 Page 2 of 10