ib technology
Operation of MicroRWD module only with 5 volt external supply
With a MicroRWD module fitted and the 13.56MHz or 125kHz antenna selected, the module
can be powered from an external 5 volt stabilised supply connected to CON J3 or CON J9.
The interface and communication pins can also be accessed directly from CON J9. For this
case the links J2, J4, J5, J7 can be removed to ensure that only the MicroRWD module is
powered and the MAX202 and the USB module (if fitted) are OFF.
Operation of MicroRWD module using RS232 interface
The MicroRWD module can be powered from an external 5 volt stabilised or 9-12 volt un-
regulated supply (Link J2 set accordingly). For RS232 communication, link J7 should be
closed to power the MAX202 device. A standard RS232 extension cable (straight-through,
pin-to-pin) is used to connect CON J10 to a PC COM port or other host RS232 interface.
Operation of MicroRWD module using USB interface (if fitted)
The MicroRWD module can be connected to and powered from an external USB bus.
To ensure the board consumes minimum power, links J2 and J7 should be removed to
disconnect the MAX202 power and regulator supply. Links J4 and J5 should then be closed
to connect the external USB bus 5 volt supply to the USB module and the MicroRWD itself.
The Universal RFID socket board uses the low-cost FTDI (Future Technology Devices
International Ltd) MM232R “serial to USB converter” module. If not already fitted, the
module can be purchased on-line from
http://www.ftdichip.com/
FTDI USB – serial interface module MM232R
The USB module should be connected to the PC USB port using a standard USB connecting
cable. All the Windows applications for the MicroRWD module currently communicate with
the serial COM ports and assume RS232 connection. FTDI provide a VCP (Virtual COM
Port) driver for the MM232R module that allows standard RS232 communication programs to
operate over the USB bus. The VCP drivers for various Operating Systems can be
downloaded from
http://www.ftdichip.com/Drivers/VCP.htm
and installed according to the
supplied instructions (VCP driver file: CDM 2.00.00 or later). With the Universal RFID
board connected to the USB bus, the Windows applications can be run in the usual manner
with a COM port selected higher than the maximum COM port number on the PC being used.
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