Hi All,
I have been looking around and not had much luck in finding someone with a similar problem (i.e. answer).
To date I have an application that reads and writes data to Mifare 1K Classic cards. The 'basic' sequence of events is:
Look for a card -> Read some data -> Write some data -> Sleep -> Look for card.... etc.
To speed things up I'd really like my app to be able to process multiple cards (i.e. instead of presenting 1 card to the reader each time, you present 2 or even 5).
Now I'm pretty sure I've read in some of the NXP documentation that multiple cards can be read in the field - it's just that you can't tell which one will get preference - so my assumption that you could some how put a card to sleep after you were finished with it. As such I decided to try the HALT A command like so:
Look for a card -> Read some data -> Write some data -> HALT A-> Look for card....
And to my disappointment the card read on the second go was.... (drum roll) the first one again.
I was wondering if anyone had any wisdom to cast on my situation? Am I going on a wild goose chase? Will I never find the holy grail of multiple cards?
Thanks for reading and please let me know if you have any info... or know anywhere I can look for info (I promise I'm not just one of these lazy people that doesn't bother looking at the doco before asking questions; I look at it mighty quickly though...). Or even just have a good story to tell... 
Cheers,
Aaron