Emilio Ficara writes:
The circuit is based on low-cost AtTiny2313 ATMEL microcontroller. It is able to read 125KHz RFID tags. Every tag is read then decoded, and its code is transmitted as ascii chars on the serial output. If the RFID code read is the same that is recorded in the micro non-volatile memory, then a relay pulses for 1,5 seconds, acting as electronic lock. The code stored in non-volatile memory is taken from the FIRST tag that is read from the circuit after burning the micro. The downloadable zip file contains the schematic diagram, the printed circuit board layout (single face, PDF 1:1 format) and the object file to burn in the micro. The circuit was published by me on italian magazine “CQ Elettronica” in the May 2009 issue, but the zip file can be freely downloaded from my site.
Generic 125KHz RFID tag reader and electronic - [Link]