I have installed several "NFC tools" apps, and I am able to read a NFC door card. It seems to be able to duplicate it (when I'll have a blank NFC card) or even write new NFC tags.
But I'd like to do something else:
How to make my Android device act as a NFC tag?
Example: since I can read and get the hexadecimal codes from my NFC door card, I'd like to make my smartphone act as a NFC card, so that, if I forget my door card, my smartphone could serve as a NFC tag.
How to do this?
PS: it is surely possible, because when paying with a smartphone ("contactless payment with phone"), the smartphone acts as a NFC device indeed for another reader (typically the shop credit card reader).