CH4 - GINA Project

samaljunid wrote: How to build up my own RFID pasif reader without buying the set? How to build the RFID pasif reader by using PIC Microchip IC?

It would take a lot of tinkering to build your own reader. It can be done, but it's outside the scope of the book, and outside of my time constraints to be able to detail it here. Basically, you have to build a resonator and read variances in the field as the passive tag pulls power from the reader field and sends back its ID to you. The data encoding method and data bit rate would all have to be taken into account and you'd have to program your PIC to adjust for data timing and decipher the data encoding method... then you could build your own reader.

Honestly though, if you don't want to buy a kit, but also don't want to go through the hassle of building it from scratch, you can easily just buy an RFID reader IC like the one used on the Phidgets USA reader board... it's an EM4907 and it does pretty much everything you need... it generates the resonant field (you supply tuned antenna), decodes the RFID tag ID, etc. It's a fairly cheap IC, so if you just don't want to buy the kit because of the cost, building your own reader using this IC is far more economical than using a PIC and all the extra parts required to build it from scratch.

It seems the only problem you might experience is that the system simply doesn't register any tag reads at all. The best way is to just download and check. I'm trying to get the author of modified pGina DLL files for RFIDGina to recompile with the new drivers and give me the source so I can post it.

Excellent news . I will look forward to it being posted, let the bugging of Amal commence!

I have just downloaded the Windows GINA replacement.  Unfortunately it doesn't work for me.  When I try to login using the RFID reader, the card is read and then I get an Error dialog for WINLOGON.EXE as soon as I press OK the system reboots.

Fortunately if I enter my credentials from the keyboard it works OK, so I can get in and remove the registry entries, though Winlogon still errors out it is no longer critical and the desktop loads OK.

I am running Windows XP Professional with all the latest service pack and hotfixes.  Trying to login using a domain account.  It so happens that I am currently getting the "You must change your password in 5 days" dialog.  Maybe your replacement GINA doesn't account for this particular situation?

Thanks, Dan

To answer your questions

    - Regular 32 bit windows

    - No other GINA replacements loaded

My guess is the change password dialog - so let me get rid of that and see if it fixes the problem, I'll report back later.

Thanks for the exceptionally quick reply.