Just a note about the Long-Range RFID modules available from Linksprite and other places.
After a lot of playing around and searching I have found that there are two slightly different versions - one that communicates over USB, the other by UART/TTL serial. The hardware is the same (and they may have connectors for both) but the firmware in the Microcontroller is slightly different.
Before purchasing one of these devices, be SURE that you are purchasing the UART version for use with the Arduino serial ports....
If I obtain further information (such as how to reflash the microcontroller) will post it here.
Found some more info on the LinkSprite Forums: http://www.linksprite.com/forum/index.php?topic=150.0 . Is it possible to convert the USB version of the Sold Digi RFID reader to serial interface by downloading the appropriate firmware to it? If so, can you send me the firmware file and instructions how to do this. This project is now moving fast.
USB can be converted into TTL.And baud rate only through to download program is modified. First, you need a programmer and, refer to the attachment "2012_08_14_12_56_11.jpg" Second, please note that the chips AS399X. If it is AS3991, please download "as399xdemo3991uart115200 hex" or "as399xdemo3991uart_9600.hex" If it is AS3992, please download "as399xdemo115200_3992.hex" or "as399xdemo_9600_3992.hex" Connection method, please refer to annex "IMAG0253.jpg" Third,JTAG conversion module Schematic please download "SCH _ C2CKC2D.pdf" Usually we don't recommend that their download program.Avoid the wrong operation, and cause the damage of the module.Usually customers request, we help the customer to complete.