Hi All,
I have an application for a low security access control system. What I
propose is to use 256 byte Smart Cards (correct name?) as electronic
keys to enter rooms internal to a business. This is not a Fort Knox type
application, the customer just wants to limit customer access to the room
that they've paid to use. Has anyone used these type of cards before?
IIRC, they are basically a 256 byte EEPROM with an I2C interface. Farnell
do have the cards & reader frame/contact assembly quite cheaply. The
assembly has a switch which closes when the card is fully inserted into it.
Are there any rules on applying power to the card? Do you have to switch
power on/off when the card is inserted/removed or is the +5V rail always
left applied to the reader contacts? I'm planning to have a PIC in each
reader with a RS485 network to log access from a central PC. The PC
will also program the cards each time with a new access code tied to the
room booking system. The PC will update the reader PIC with the new
code at the same time. Thinking about it, this is more or less like Hotels
use use these days for room access. Any comments welcome.  :-)
Regards...
___________________________________________
David Duffy        Audio Visual Devices P/L
U8, 9-11 Trade St, Cleveland 4163 Australia
Ph: +61 7 38210362   Fax: +61 7 38210281
New Web: www.audiovisualdevices.com.au
New email: avd@audiovisualdevices.com.au
___________________________________________

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.