AN3255 Datasheet, PDF (1/24 Pages) STMicroelectronics – Building an RFID short-range reader using the STM8S-DISCOVERY

AN3255
Application note
Building an RFID short-range reader
using the STM8S-DISCOVERY
Application overview
High frequency 13,56 MHz RFID solutions offer ideal close-proximity identification for
product authentication, parcel tracking, document management, library and ticketing
applications.
This application note describes how to build an RFID (radio frequency identification) short-
range reader using STMicroelectronics STM8S-DISCOVERY and ISO14443 type-B CR14
contactless coupler. The STM8S-DISCOVERY and the CR14 communicate through an I²C
bus.
The resulting RFID reader can exchange data with ISO 14443-2 type-B proximity PICCs
(proximity integrated coupling cards) also called tags. Communications are possible only
when the tags are present in the electromagnetic field generated by the reader built-in
antenna.
Once the STM8S-DISCOVERY is powered up through a USB cable connected to the host
PC, an electromagnetic field is generated by the RFID reader. A beep is emitted and the
LED LD1 briefly lights up when an ISO 14443-2 type-B proximity tag is detected by the
reader and its unique identifier (UID) successfully read.
The STM8S-DISCOVERY can be used to evaluate the main features of all STM8S MCUs,
even if it is built on an STM8S105C6T6.
Reference documents
■ STM8S-DISCOVERY evaluation board user manual (UM0817).
■ Developing and debugging your STM8S-DISCOVERY application code (UM0834).
■ User manual “CR14 and CRX14 reference design PCB Gerber files” (UM0672) and RFID
Gerber files.
■ CR14 datasheet: “Low cost ISO14443 type-B contactless coupler chip with anti-collision
and CRC management”
■ SRI2K datasheet: “13,56 MHz short-range contactless memory chip with 2048 bit
EEPROM and anti-collision functions”
■ Application note “Antenna (and associated components) matching-circuit calculation of
the CRX14 coupler” (AN1806)
■ Application note “How to design a 13.56 MHz customized antenna” (AN2866)
These documents can be downloaded from http://www.st.com.
October 2010
Doc ID 17784 Rev 1
1/24
www.st.com