Small update: if I put one card and the tag I get the “multi card” flag set.
If I put the two cards in the field, I get the SN of one of the cards and the “multi card” flag not set !
And, as already said, if i place the two cards and the tag in the field, the “multi card” flag doesnot get set.
And it seems the ISO15693_Inventory (0x10) command doesn’t work as documented (sending the command as detailed on page 29 of the docs results in a "parameter error), just like MF_GET_SNR (that doesn’t halt the card as said on page 24).
PS: LEDs need the current limiter resistor, right? And how much current is available for them and for the buzzer?
Please, some decent documentation is needed to avoid wasting time!