Ok so this reader will read mifare cards of 125kHz only. I have cards and tags for 13.56MHz so I would need to get new cards. Because I dont see any UHF 13.56Mhz readers, im guessing because UHF starts higher. So I really need a UHF reader and a set of UHF tags/cards as well, right?
I have seen 13MHz USB readers before (although I can't remember if I tried it on a pi), and I don't know where it came from (I didn't get it).
Normally UHF refers to much higher frequencies (300MHz - 3000MHz), if rfid/nfc stuff refers to 13MHz as UHF then they're doing something different to the rest of things using rf systems,