I have installed an MFRC522 RFID reader in my house. The main use so far is to tell the house I've arrived using an RFID keychain, by leaving it in the key holder.
I would also like for the house to detect when I'm gone, and I was thinking that, if I can detect when a tag is present, I should also be able to detect when it is not. However, this poses some challenges like the following:
- Should I be constantly reading the tag until it disappears from range? (when I take it from the key holder).
- What if I have more than one RFID Keychain/Tag in the range of the reader? (because there could be other keychains in the same key holder). Would I get multiple readings or could one tag interfere with another in some way?
I realize that maybe this is not the typical RFID scenario when the tag is scanned and then moved away from the reader. I've been searching about "RFID tag absence detection" but I've only found what seemed to me like very theoretical papers.
Do you have any advice or experience in implementing something like this?